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American football, referred to simply as football in the United States and Canada and also known as gridiron, is a
team sport A team sport includes any sport where individuals are organized into opposing sports team, teams which compete to win. Team members act together towards a shared objective. This can be done in a number of ways such as outscoring the opposing ...
played by two teams of eleven players on a rectangular
field Field may refer to: Expanses of open ground * Field (agriculture), an area of land used for agricultural purposes * Airfield, an aerodrome that lacks the infrastructure of an airport * Battlefield * Lawn, an area of mowed grass * Meadow, a grassl ...

field
with goalposts at each end. The offense, the team with possession of the oval-shaped
football Football is a family of s that involve, to varying degrees, a to score a . Unqualified, normally means the form of football that is the most popular where the word is used. Sports commonly called ''football'' include (known as ''soccer'' ...
, attempts to advance down the field by
running Running is a method of terrestrial locomotion Terrestrial locomotion has evolved Evolution is change in the heritable Heredity, also called inheritance or biological inheritance, is the passing on of Phenotypic trait, traits from ...
with the ball or passing it, while the
defense Defense or defence may refer to: Tactical, martial, and political acts or groups * Defense (military) A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is ...
, the team without possession of the ball, aims to stop the offense's advance and to take control of the ball for themselves. The offense must advance at least ten yards in four downs or plays; if they fail, they turn over the football to the defense, but if they succeed, they are given a new set of four downs to continue the
drive Drive or The Drive may refer to: Motoring * Driving, the act of controlling a vehicle * Road trip, a journey on roads Roadways Roadways called "drives" may include: * Driveway, a private road for local access to structures, abbreviated "drive" * ...

drive
. Points are scored primarily by advancing the ball into the opposing team's
end zone The end zone is the Goal (sport), scoring area on the field, according to gridiron football, gridiron-based codes of football. It is the area between the end line and Goal line (gridiron football), goal line bounded by the sidelines. There are ...
for a
touchdown A touchdown (abbreviated as TD) is a scoring play in gridiron football Gridiron football,
touchdown
or kicking the ball through the opponent's goalposts for a
field goal A field goal (FG) is a means of scoring in gridiron football Gridiron football, ...

field goal
. The team with the most points at the end of a game wins. American football evolved in the United States, originating from the sports of
soccer Association football, more commonly known as simply football or soccer, is a team sport A team sport includes any sport Sport pertains to any form of Competition, competitive physical activity or game that aims to use, maintain ...
and
rugby Rugby may refer to: Sports Rugby codes * Rugby football in various forms: ** Rugby league: 13 players per side *** Masters Rugby League *** Mod league *** Rugby league nines *** Rugby league sevens *** Touch (sport) *** Wheelchair rugby league ** ...
. The first American football match was played on November 6, 1869, between two college teams,
Rutgers Rutgers University (RU; ), officially known as Rutgers, The State University of New Jersey, is a Public university, public land-grant research university based in New Brunswick, New Jersey. Chartered in 1766, Rutgers was originally called Queen' ...
and
Princeton Princeton University is a private Private or privates may refer to: Music * "In Private "In Private" was the third single in a row to be a charting success for United Kingdom, British singer Dusty Springfield, after an absence of nearly two ...
, using rules based on the rules of soccer at the time. A set of rule changes drawn up from
1880 Events January–March * January 22 Events Pre-1600 *613 __NOTOC__ Year 613 ( DCXIII) was a common year starting on MondayA common year starting on Monday is any non-leap year A leap year (also known as an intercalary year or b ...
onward by
Walter Camp Walter Chauncey Camp (April 7, 1859 – March 14, 1925) was an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven ...
, the "Father of American Football", established the snap, the
line of scrimmage In gridiron football Gridiron football,"Gridiron football"
''Encyclop ...
, eleven-player teams, and the concept of downs. Later rule changes legalized the
forward pass In several forms of football Football is a family of team sport A team is a neutral_zone_and_specified_the_size_and_shape_of_the_football._The_sport_Comparison_of_American_and_Canadian_football.html" ;"title="neutral zone (gridiron football)">neutral zone and specified the size and shape of the football. The sport is_closely_related_to_ is_closely_related_to_Canadian_football">Comparison_of_American_and_Canadian_football">is_closely_related_to_Canadian_football,_which_evolved_in_parallel_with_and_at_the_same_time_as_the_American_game_(although_their_rules_were_Burnside_rules.html" ;"title="Canadian_football.html" ;"title="Comparison of American and Canadian football">is closely related to Canadian football">Comparison of American and Canadian football">is closely related to Canadian football, which evolved in parallel with and at the same time as the American game (although their rules were Burnside rules">developed independently from those of Camp). Most of the features that distinguish American football from rugby and soccer are also present in Canadian football. The two sports are considered the primary variants of gridiron football. American football is the most popular sport in the United States. The most popular forms of the game are Professional football (gridiron), professional and college football, with the other major levels being
high school A secondary school describes an institution that provides secondary education Secondary education covers two phases on the International Standard Classification of Education The International Standard Classification of Education (ISCED) is a ...
and youth football. , nearly 1.1 million high school athletes and 70,000 college athletes play the sport in the United States annually. The
National Football League The National Football League (NFL) is a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any s ...
, the most popular American football league, has the highest average attendance of any professional sports league in the world. Its championship game, the
Super Bowl The Super Bowl is the annual championship game of the National Football League (NFL). It has served as the final game of every NFL season since 1966, replacing the NFL Championship Game. Since 2004, the game has been played on the first Sunday ...
, ranks among the most-watched club sporting events in the world. The league has an annual revenue of around US$15 billion, making it the most valuable sports league in the world. Other professional leagues exist worldwide, but the sport does not have the international popularity of other American sports like
baseball Baseball is a bat-and-ball gameBat-and-ball may refer to: *Bat-and-ball games Bat-and-ball games (or safe haven games) are field games played by two opposing teams, in which the action starts when the defending team throws a ball at ...

baseball
or
basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular court A court is any person or institution, often as a government institution, with the authority to Adjudication, ...

basketball
.


Etymology and names

In the United States, American football is referred to as "football". The term "football" was officially established in the rulebook for the 1876 college football season, when the sport first shifted from soccer-style rules to rugby-style rules. Although it could easily have been called "rugby" at this point, Harvard, one of the primary proponents of the rugby-style game, compromised and did not request the name of the sport be changed to "rugby". The terms " gridiron" or "American football" are favored in English-speaking countries where other types of
football Football is a family of s that involve, to varying degrees, a to score a . Unqualified, normally means the form of football that is the most popular where the word is used. Sports commonly called ''football'' include (known as ''soccer'' ...
are popular, such as the United Kingdom, Ireland, New Zealand, and Australia.


History


Early history

American football evolved from the sports of
rugby Rugby may refer to: Sports Rugby codes * Rugby football in various forms: ** Rugby league: 13 players per side *** Masters Rugby League *** Mod league *** Rugby league nines *** Rugby league sevens *** Touch (sport) *** Wheelchair rugby league ** ...
and
soccer Association football, more commonly known as simply football or soccer, is a team sport A team sport includes any sport Sport pertains to any form of Competition, competitive physical activity or game that aims to use, maintain ...
. Rugby, like American football, is a sport where two competing teams vie for control of a ball, which can be kicked through a set of goalposts or run into the opponent's goal area to score points. What is considered to be the first American football game was played on November 6, 1869, between
Rutgers Rutgers University (RU; ), officially known as Rutgers, The State University of New Jersey, is a Public university, public land-grant research university based in New Brunswick, New Jersey. Chartered in 1766, Rutgers was originally called Queen' ...
and
Princeton Princeton University is a private Private or privates may refer to: Music * "In Private "In Private" was the third single in a row to be a charting success for United Kingdom, British singer Dusty Springfield, after an absence of nearly two ...
, two college teams. They consisted of 25 players per team and used a round ball that could not be picked up or carried. It could, however, be kicked or batted with the feet, hands, head or sides, with the objective being to advance it into the opponent's goal. Rutgers won the game 6–4. Collegiate play continued for several years with matches played using the rules of the host school. Representatives of Yale,
Columbia Columbia may refer to: * Columbia (personification), the historical female national personification of the United States, and a poetic name for the Americas Places North America Natural features * Columbia Plateau, a geologic and geographic regio ...

Columbia
, Princeton and Rutgers met on October 19, 1873, to create a standard set of rules for use by all schools. Teams were set at 20 players each, and fields of were specified. Harvard abstained from the conference, as they favored a rugby-style game that allowed running with the ball. After playing
McGill University McGill University is a public university, public research university located in Montreal, Quebec, Canada. Founded in 1821 by royal charter granted by George IV, King George IV,Frost, Stanley Brice. ''McGill University, Vol. I. For the Advanceme ...
using both Canadian and American rules, the Harvard players preferred the Canadian style of having only 11 men on the field, running the ball without having to be chased by an opponent, the forward pass, tackling, and using an oblong instead of a round ball. An 1875 Harvard–Yale game played under rugby-style rules was observed by two Princeton athletes who were impressed by it. They introduced the sport to Princeton, a feat the
Professional Football Researchers Association The Professional Football Researchers Association (PFRA) is an organization of researchers whose mission is to preserve and, in some cases, reconstruct professional football history. It was founded on June 22, 1979 in Canton, Ohio by writer/histo ...
compared to "selling
refrigerator A refrigerator (colloquially fridge) is a commercial and home appliance A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household A household co ...

refrigerator
s to
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Eskimo
s". Princeton, Harvard, Yale, and Columbia then agreed to intercollegiate play using a form of
rugby union Rugby union, commonly known simply as rugby, is a Contact sport#Terminology, close-contact team sport that originated in England in the first half of the 19th century. One of the Comparison of rugby league and rugby union, two codes of rugby f ...
rules with a modified scoring system. These schools formed the
Intercollegiate Football Association The Intercollegiate Football Association (IFA), also known as the American Intercollegiate Football Association, was one of the earliest college football College football is gridiron football consisting of American football in the United Stat ...
, although Yale did not join until 1879. Yale player
Walter Camp Walter Chauncey Camp (April 7, 1859 – March 14, 1925) was an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven ...
, now regarded as the "Father of American Football", secured rule changes in 1880 that reduced the size of each team from 15 to 11 players and instituted the snap to replace the chaotic and inconsistent
scrum Scrum may refer to: * Scrum (rugby), a method of restarting play in rugby union and rugby league ** Scrum (rugby union), scrum in rugby union * Scrum, an offensive melee formation in Japanese game Bo-taoshi * Media scrum, an impromptu press confe ...
.


Evolution of the game

The introduction of the snap resulted in an unexpected consequence. Prior to the snap, the strategy had been to punt if a scrum resulted in bad field position. However, a group of Princeton players realized that as the snap was uncontested, they could now hold the ball indefinitely to prevent their opponent from scoring. In 1881, in a game between Yale and Princeton, both teams used this strategy to maintain their undefeated records. Each team held the ball, gaining no ground, for an entire half, resulting in a 0–0 tie. This "block game" proved extremely unpopular with both teams' spectators and fans. A rule change was necessary to prevent this strategy from taking hold, and a reversion to the scrum was considered. However, Camp successfully proposed a rule in 1882 that limited each team to three downs, or tackles, to advance the ball . Failure to advance the ball the required distance within those three downs would result in control of the ball being forfeited to the other team. This change effectively made American football a separate sport from rugby, and the resulting five-yard lines added to the field to measure distances made it resemble a gridiron in appearance. Other major rule changes included a reduction of the field size to and the adoption of a scoring system that awarded four points for a touchdown, two for a safety and a goal following a touchdown, and five for a goal from the field. Additionally, tackling below the waist was legalized, and a static
line of scrimmage In gridiron football Gridiron football,"Gridiron football"
''Encyclop ...
was instituted. Despite these new rules, football remained a violent sport. Dangerous mass-formations like the
flying wedge A flying wedge (also called flying V or wedge formation, or simply wedge) is a configuration created from a body moving forward in a triangular formation. This V-shaped arrangement began as a successful military strategy in ancient times when inf ...
resulted in serious injuries and deaths. A 1905 peak of 19 fatalities nationwide resulted in a threat by President
Theodore Roosevelt Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or his initials T. R., was an American politician, statesman, conservationist, naturalist, historian, and writer who served as the 26th president o ...

Theodore Roosevelt
to abolish the game unless major changes were made. In response, 62 colleges and universities met in New York City to discuss rule changes on December 28, 1905. These proceedings resulted in the formation of the Intercollegiate Athletic Association of the United States, later renamed the
National Collegiate Athletic Association The National Collegiate Athletic Association (NCAA) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and ...
(NCAA). The legal
forward pass In several forms of football Football is a family of team sport A team is a
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._Other_rule_changes_introduced_that_year_included_the_reduction_of_playing_time_from_70_to_60_minutes_and_an_increase_of_the_distance_required_for_a_first_down_from_._To_reduce_infighting_and_dirty_play_between_teams,_the_Neutral_zone_(gridiron_football).html" ;"title="Harvard_Stadium#Impact_on_American_Football.html" "title="roup (disambiguation), group of individuals (human or non-human) working together to achieve their goal. As defined by Professor Leigh Thompson (academic), ...
was introduced in 1906, although its impact was initially minimal due to the restrictions placed on its use. The idea of a 40-yard-wider field was opposed by Harvard due to the size of the new Harvard Stadium#Impact on American Football">Harvard Stadium Harvard Stadium is a U-shaped college football stadium in the northeast United States The United States of America (USA), commonly known as the United States (U.S. or US), or America, is a country Contiguous United States, primarily located ...
. Other rule changes introduced that year included the reduction of playing time from 70 to 60 minutes and an increase of the distance required for a first down from . To reduce infighting and dirty play between teams, the Neutral zone (gridiron football)">neutral zone was created along the width of the football before the snap. Scoring was also adjusted: points awarded for field goals were reduced to three in 1909 and points for touchdowns were raised to six in 1912. Also in 1912, the field was shortened to long, two end zones were created, and teams were given four downs instead of three to advance the ball . The roughing the passer penalty was implemented in 1914, and eligible players were first allowed to catch the ball anywhere on the field in 1918.


Professional era

On November 12, 1892,
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Pudge Heffelfinger
was paid $500 to play a game for the
Allegheny Athletic Association The Allegheny Athletic Association was an athletic club that fielded the first ever professional American football player and later the first fully professional football team. The organization was founded in 1890 as a regional athletic club in Al ...
in a match against the Pittsburgh Athletic Club. This is the first recorded instance of a player being paid to participate in a game of American football, although many athletic clubs in the 1880s offered indirect benefits, such as helping players attain employment, giving out trophies or watches that players could pawn for money, or paying double in expense money. Despite these extra benefits, the game had a strict sense of amateurism at the time, and direct payment to players was frowned upon, if not prohibited outright. Over time, professional play became increasingly common, and with it came rising salaries and unpredictable player movement, as well as the illegal payment of college players who were still in school. The
National Football League The National Football League (NFL) is a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any s ...
(NFL), a group of professional teams that was originally established in 1920 as the American Professional Football Association, aimed to solve these problems. This new league's stated goals included an end to bidding wars over players, prevention of the use of college players, and abolition of the practice of paying players to leave another team. By 1922, the NFL had established itself as America's premier professional football league. The dominant form of football at the time was played at the collegiate level. The upstart NFL received a boost to its legitimacy in 1925, however, when an NFL team, the
Pottsville Maroons The Pottsville Maroons were an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American ...
, defeated a team of
Notre Dame Notre Dame, French for "Our Lady", a title of Mary, mother of Jesus, most commonly refers to: * Notre-Dame de Paris, a cathedral in Paris, France * University of Notre Dame, a university in Indiana, United States ** Notre Dame Fighting Irish, the u ...
all-stars in an
exhibition game An exhibition game (also known as a friendly, a scrimmage, a demonstration, a preseason game, a warmup match, or a preparation match, depending at least in part on the sport) is a sporting event Sport pertains to any form of competitive p ...

exhibition game
. A greater emphasis on the passing game helped professional football to distinguish itself further from the college game during the late 1930s. Football, in general, became increasingly popular following the 1958 NFL Championship game, a match between the
Baltimore Colts Baltimore ( , locally: ) is the most populous city The United Nations uses three definitions for what constitutes a city, as not all cities in all jurisdictions are classified using the same criteria. Cities may be defined as the city prope ...
and the
New York Giants The New York Giants are a professional American football team based in the New York metropolitan area. The Giants compete in the National Football League (NFL) as a member club of the league's National Football Conference (NFC) NFC East, East ...

New York Giants
that is still referred to as the "Greatest Game Ever Played". The game, a 23–17 overtime victory by the Colts, was seen by millions of television viewers and had a major impact on the popularity of the sport. This, along with the innovations introduced by the new
American Football League The American Football League (AFL) was a major professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any ...
(AFL) in the early 1960s, helped football to become the most popular sport in the United States by the mid-1960s. The rival AFL arose in 1960 and challenged the NFL's dominance. The AFL began in relative obscurity but eventually thrived, with an initial television contract with the
ABC ABC are the first three letters of the Latin script known as the alphabet. ABC or abc may also refer to: Arts, entertainment, and media Broadcasting * American Broadcasting Company, a commercial U.S. TV broadcaster ** Disney–ABC Television ...
television network. The AFL's existence forced the conservative NFL to expand to Dallas and Minnesota in an attempt to destroy the new league. Meanwhile, the AFL introduced many new features to professional football in the United States: official time was kept on a scoreboard clock rather than on a watch in the referee's pocket, as the NFL did; optional two-point conversions by pass or run after touchdowns; names on the jerseys of players; and several others, including expansion of the role of minority players, actively recruited by the league in contrast to the NFL. The AFL also signed several star college players who had also been drafted by NFL teams. Competition for players heated up in 1965, when the AFL
New York Jets The New York Jets are a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangula ...
signed rookie
Joe Namath Joseph William Namath (; ; born May 31, 1943) is a former American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any ...

Joe Namath
to a then-record $437,000 contract (equivalent to $ in ). A five-year, $40 million
NBC The National Broadcasting Company (NBC) is an American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the United States The United States of America (USA), c ...
television contract followed, which helped to sustain the young league. The bidding war for players ended in 1966 when NFL owners approached the AFL regarding a merger, and the two leagues agreed on one that took full effect in 1970. This agreement provided for a common draft that would take place each year, and it instituted an annual World Championship game to be played between the champions of each league. This championship game began play at the end of the 1966 season. Once the merger was completed, it was no longer a championship game between two leagues and reverted to the NFL championship game, which came to be known as the
Super Bowl The Super Bowl is the annual championship game of the National Football League (NFL). It has served as the final game of every NFL season since 1966, replacing the NFL Championship Game. Since 2004, the game has been played on the first Sunday ...
. College football maintained a tradition of postseason
bowl games In North America, a bowl game is one of a number of post-season college football College football is gridiron football consisting of American football in the United States, American football played by teams of student athletes fielded by H ...

bowl games
. Each bowl game was associated with a particular conference and earning a spot in a bowl game was the reward for winning a conference. This arrangement was profitable, but it tended to prevent the two top-ranked teams from meeting in a true national championship game, as they would normally be committed to the bowl games of their respective conferences. Several systems have been used since 1992 to determine a national champion of college football. The first was the
Bowl Coalition The Bowl Coalition was formed through an agreement among Division I-A college football College football is gridiron football consisting of American football in the United States, American football played by teams of student athletes fielded b ...
, in place from 1992 to 1994. This was replaced in 1995 by the
Bowl Alliance The Bowl Alliance was an agreement among college football bowl games (specifically the Sugar, Orange, and Fiesta Bowls) for the purpose of trying to match the top two teams in a national championship bowl game and to provide quality bowl game mat ...
, which gave way in 1997 to the
Bowl Championship Series The Bowl Championship Series (BCS) was a selection system that created five bowl game In North America, a bowl game is one of a number of post-season college football games that are primarily played by teams belonging to the NCAA's Divisio ...
(BCS). The BCS arrangement proved to be controversial, and was replaced in 2014 by the
College Football Playoff The College Football Playoff (CFP) is an annual postseason knockout invitational tournament to determine a national champion for the National Collegiate Athletic Association (NCAA) NCAA Division I Football Bowl Subdivision, Division I Footbal ...
(CFP).


Teams and positions

A football game is played between two teams of 11 players each.NFL Rules 2012, p. 21.NFHS Rules 2012, p. 11. Playing with more on the field is punishable by a penalty.NCAA Rules 2011–2012, p. 107.NFHS Rules 2012, pp. 71–72. Teams may substitute any number of their players between downs;NFL Rules 2012, pp. 21–22.NCAA Rules 2011–2012, pp. 53–54.NFHS Rules 2012, pp. 45–46. this "platoon" system replaced the original system, which featured limited substitution rules, and has resulted in teams utilizing specialized offensive, defensive and
special teams In American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American football field, field with ...
units. Individual players in a football game must be designated with a
uniform number In team A team is a group of individuals (human or non-human) working together to achieve their goal A goal is an idea of the future or desired result that a person or a group of people envision, Planning, plan and commit to achieve. ...
between 1 and 99. NFL teams are required to number their players by a league-approved numbering system, and any exceptions must be approved by the
Commissioner A commissioner is, in principle, a member of a commission Commission or commissioning may refer to: Business and contracting * Commission (remuneration), a form of payment to an agent for services rendered ** Commission (art), the purchase or the ...

Commissioner
. NCAA and NFHS teams are "strongly advised" to number their offensive players according to a league-suggested numbering scheme.NCAA Rules 2011–2012, pp. 21–22.NFHS Rules 2012, pp. 16–17. Although the sport is played almost exclusively by men, women are eligible to play in high school, college, and professional football. No woman has ever played in the NFL, but women have played in high school and college football games. In 2018, 1,100 of the 225,000 players in
Pop Warner Little Scholars Pop Warner Little Scholars, commonly known simply as Pop Warner, is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized ...
youth football were girls, and around 11% of the 5.5 million Americans who report playing tackle football are female according to the Sports and Fitness Industry Association. Women can also serve as officials; Sarah Thomas became the NFL's first female official in 2015.


Offensive unit

The role of the offensive unit is to advance the football down the field with the ultimate goal of scoring a
touchdown A touchdown (abbreviated as TD) is a scoring play in gridiron football Gridiron football,
touchdown
. The offensive team must line up in a legal
formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary m ...
before they can snap the ball. An offensive formation is considered illegal if there are more than four players in the
backfield The offensive backfield is the area of an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any sport Sport pe ...

backfield
or fewer than five players numbered 50–79 on the offensive line.NCAA Rules 2011–2012, p. 15.NFL Rules 2012, pp. 21–24.NFHS Rules 2012, pp. 57–58. Players can line up temporarily in a position whose eligibility is different from what their number permits as long as they report the change immediately to the referee, who then informs the defensive team of the change.NFL Rules 2012, pp. 36, 40. Neither team's players, except the
center Center or centre may refer to: Mathematics *Center (geometry) In geometry, a centre (or center) (from Ancient Greek language, Greek ''κέντρον'') of an object is a point in some sense in the middle of the object. According to the speci ...
(C), are allowed to line up in or cross the neutral zone until the ball is snapped. Interior offensive linemen are not allowed to move until the snap of the ball. The main backfield positions are the
quarterback The quarterback (commonly abbreviated "QB"), colloquially known as the "signal caller", is a position in gridiron football Gridiron football,
quarterback
(QB), halfback/tailback (HB/TB) and fullback (FB). The quarterback is the leader of the offense. Either the quarterback or a coach calls the plays. Quarterbacks typically inform the rest of the offense of the play in the
huddle In sport, a huddle is an action of a team gathering together, usually in a tight circle, to strategize, motivate or celebrate. It is a popular strategy for keeping opponents insulated from sensitive information, and acts as a form of insulation wh ...

huddle
before the team lines up. The quarterback lines up behind the center to take the snap and then hands the ball off, throws it or runs with it. The primary role of the halfback, also known as the running back or tailback, is to carry the ball on running plays. Halfbacks may also serve as receivers. Fullbacks tend to be larger than halfbacks and function primarily as blockers, but they are sometimes used as runners in short-yardage situations and are seldom used in passing situations. The
offensive line Image:Linemen.svg, 350px, A diagram of the linemen, with defensive linemen (in 4-3 formation) in red and offensive linemen in green. In gridiron football, a lineman is a player who specializes in play at the line of scrimmage. The linemen of the ...
(OL) consists of several players whose primary function is to
block Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 t ...
members of the defensive line from tackling the ball carrier on running plays or sacking the quarterback on passing plays. The leader of the offensive line is the center, who is responsible for snapping the ball to the quarterback, blocking, and for making sure that the other linemen do their jobs during the play. On either side of the center are the guards (G), while
tackles Tackle may refer to: * In football: ** Tackle (football move), a play in various forms of football ** Tackle (gridiron football position), a position in American football and Canadian football ** Dump tackle, a forceful move in rugby of picking up ...
(T) line up outside the guards. The principal receivers are the
wide receiver A wide receiver (WR), also referred to as a wideout, historically a split end, is an eligible receiver in gridiron football. A key skill position of the offense (American football), offense, WR gets its name from the player being split out "wi ...

wide receiver
s (WR) and the
tight end The tight end (TE) is a position in American football, arena football, and Canadian football, on the offense (sports), offense. The tight end is often a hybrid position with the characteristics and roles of both an offensive lineman and a wide re ...
s (TE). Wide receivers line up on or near the line of scrimmage, split outside the line. The main goal of the wide receiver is to catch passes thrown by the quarterback, but they may also function as decoys or as blockers during running plays. Tight ends line up outside the tackles and function both as receivers and as blockers.


Defensive unit

The role of the defense is to prevent the offense from scoring by
tackling Tackle may refer to: * In football: ** Tackle (football move) Most forms of football Football is a family of team sport A team is a contact Contact may refer to: Interaction Physical interaction * Contact (geology)A geological co ...
the ball carrier or by forcing turnovers (
interception In ball-playing competitive Competition is a rivalry A rivalry is the state of two people or groups engaging in a lasting competitive relationship. Rivalry is the "against each other" spirit between two competing sides. The relationsh ...

interception
s or
fumble A fumble in gridiron football Gridiron football,"Gridiron football"
...
s). The
defensive line In gridiron football, a lineman is a player who specializes in play at the line of scrimmage. The linemen of the team currently in possession of the ball are the offensive line, while linemen on the opposing team are the defensive line. A numbe ...
(DL) consists of
defensive end Defensive end (DE) is a defensive position in the sport of gridiron football Gridiron football,
s (DE) and
defensive tackles A defensive tackle (DT) is a position in American football that will typically line up on the line of scrimmage, opposite one of the Guard (American football), offensive guards, however he may also line up opposite one of the Tackle (gridiron footb ...
(DT). Defensive ends line up on the ends of the line, while defensive tackles line up inside, between the defensive ends. The primary responsibilities of defensive ends and defensive tackles are to stop running plays on the outside and inside, respectively, to pressure the quarterback on passing plays, and to occupy the line so that the
linebacker A linebacker (LB or backer) is a playing position in gridiron football. Linebackers are members of the defensive team, and line up approximately three to five yards (4 m) behind the line of scrimmage and behind the defensive linemen. They re ...

linebacker
s can break through. Linebackers line up behind the defensive line but in front of the defensive backfield. They are divided into two types: middle linebackers (MLB) and outside linebackers (OLB). Linebackers are the defensive leaders and call the defensive plays. Their diverse roles include defending the run, pressuring the quarterback, and guarding backs, wide receivers and tight ends in the passing game. The
defensive back In gridiron football Gridiron football,"Gridiron football"
''Encyclopæ ...
field, often called the secondary, consists of
cornerback A cornerback (CB) is a members of the defensive back In gridiron football, defensive backs (DBs), also called the secondary, are the players on the defensive side of the ball who play farthest back from the line of scrimmage. They are distin ...

cornerback
s (CB) and safeties (S). Safeties are themselves divided into free safeties (FS) and strong safeties (SS). Cornerbacks line up outside the defensive formation, typically opposite a receiver to be able to cover them. Safeties line up between the cornerbacks but farther back in the secondary. Safeties are the last line of defense and are responsible for stopping deep passing plays as well as running plays.


Special teams unit

The special teams unit is responsible for all kicking plays. The special teams unit of the team in control of the ball tries to execute field goal (FG) attempts, punts and kickoffs, while the opposing team's unit will aim to block or return them. Three positions are specific to the field goal and PAT (point-after-touchdown) unit: the
placekicker Placekicker, or simply kicker (PK or K), is the player in gridiron football who is responsible for the kicking duties of Field goal (football), field goals and extra points. In many cases, the placekicker also serves as the team's kickoff specia ...
(K or PK), holder (H) and
long snapper In gridiron football, the long snapper (or deep snapper) is a special teams specialist whose duty is to snap the football over a longer distance, typically around 15 yards during Punt (gridiron football), punts, and 7–8 yards during Field goa ...
(LS). The long snapper's job is to snap the football to the holder, who will catch and position it for the placekicker. There is not usually a holder on kickoffs, because the ball is kicked off a tee; however, a holder may be used in certain situations, such as if wind is preventing the ball from remaining upright on the tee. The player on the receiving team who catches the ball is known as the
kickoff returner 200px, Devin Hester fielding a punt during special teams practice at the Chicago Bears">special_teams.html" ;"title="Devin Hester fielding a punt during special teams">Devin Hester fielding a punt during special teams practice at the Chicago Bears ...
(KR). The positions specific to punt plays are the punter (P), long snapper,
upback In American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American football field, field with go ...
and
gunner Gunner, the Gunner, Gunners or the Gunners may refer to: Places * Gunner Bay, Bermuda * Gunner River, New Zealand * Gunners Park and Shoebury Ranges, a nature reserve in Essex, England * Gunners Pond, Newfoundland and Labrador, Canada * Mount Gunn ...
. The long snapper snaps the football directly to the punter, who then drops and kicks it before it hits the ground. Gunners line up split outside the line and race down the field, aiming to tackle the
punt returner A return specialist or kick returner is a player on the special teams unit of a gridiron football team who specializes in returning punt (gridiron football), punts and kickoff (gridiron football), kickoffs. There are few players who are exclusivel ...
(PR)—the player who catches the punt. Upbacks line up a short distance behind the line of scrimmage, providing additional protection to the punter.


Rules


Scoring

In football, the winner is the team that has scored more points at the end of the game. There are multiple ways to score in a football game. The touchdown (TD), worth six points, is the most valuable scoring play in American football. A touchdown is scored when a live ball is advanced into, caught in, or recovered in the opposing team's end zone. The scoring team then attempts a try or conversion, more commonly known as the point(s)-after-touchdown (PAT), which is a single scoring opportunity. A PAT is most commonly attempted from the two- or three-yard line, depending on the level of play. If a PAT is scored by a placekick or dropkick through the goal posts, it is worth one point, typically called the extra point. If it is scored by what would normally be a touchdown it is worth two points, typically called the
two-point conversion 2005. The Bucs won on the conversion 36-35. --> In gridiron football, a two-point conversion or two-point convert is a play a team attempts instead of kicking a one-point conversion (gridiron football), conversion immediately after it scores a tou ...
. In general, the extra point is almost always successful while the two-point conversion is a much riskier play with a higher probability of failure; accordingly, extra point attempts are far more common than two-point conversion attempts. A field goal (FG), worth three points, is scored when the ball is placekicked or dropkicked through the uprights and over the crossbars of the defense's goalposts.NFL Rules 2012, pp. 57–59.NCAA Rules 2011–2012, pp. 79–80.NFHS Rules 2012, p. 66. After a PAT attempt or successful field goal, the scoring team must kick the ball off to the other team. A
safety Safety is the state of being "safe", the condition of being protected from harm Harm is a moral A moral (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European language ...
is scored when the ball carrier is tackled in their own end zone. Safeties are worth two points, which are awarded to the defense. In addition, the team that conceded the safety must kick the ball to the scoring team via a
free kick A free kick is an action used in several codes of football Football is a family of team sport A team is a [group (disambiguation), group of individuals (human or non-human) working together to achieve their goal. As defined by Professor ...
.NFL Rules 2012, p. 60


Field and equipment

Football games are played on a rectangular
field Field may refer to: Expanses of open ground * Field (agriculture), an area of land used for agricultural purposes * Airfield, an aerodrome that lacks the infrastructure of an airport * Battlefield * Lawn, an area of mowed grass * Meadow, a grassl ...

field
that measures long and wide. Lines marked along the ends and sides of the field are known as the end lines and sidelines. Goal line (American football), Goal lines are marked inward from each end line.NFL Rules 2012, p. v, 1.NCAA Rules 2011–2012, pp. 18–19, 23–24.NFHS Rules 2012, pp. 11–12, 13, 28. Weighted pylons are placed the sidelines on the inside corner of the intersections with the goal lines and end lines. White markings on the field identify the distance from the end zone. Inbound lines, or
hash marks A hash mark in sports is a short line, running perpendicular to sidelines or sideboards, that is used to mark locations. Usage in ice hockey In ice hockey, the hash marks are two pairs of parallel lines on either side of the face-off circles in ...
, are short parallel lines that mark off increments.
Yard lines The rectangular Pitch (sports field), field of play used for American football games measures long between the goal lines, and () wide. The field is made of grass. In addition, there are end zones extending another past the goal lines to the "end ...
, which can run the width of the field, are marked every . A one-yard-wide line is placed at each end of the field; this line is marked at the center of the two-yard line in professional play and at the three-yard line in college play. Numerals that display the distance from the closest goal line in yards are placed on both sides of the field every ten yards.
Goalposts In sport, a goal may refer to either an instance of scoring, or to the physical structure or area where an attacking team must send the ball or puck in order to score points. The structure of a goal varies from sport to sport, and one is placed ...
are located at the center of the plane of the two end lines. The crossbar of these posts is above the ground, with vertical uprights at the end of the crossbar apart for professional and collegiate play, and apart for high school play. The uprights extend vertically on professional fields, a minimum of on college fields, and a minimum of on high school fields. Goal posts are padded at the base, and orange ribbons are normally placed at the tip of each upright as indicators of wind strength and direction.NFL Rules 2012, p.  2.NCAA Rules 2011–2012, p. 18.NFHS Rules 2012, p. 14. The
football Football is a family of s that involve, to varying degrees, a to score a . Unqualified, normally means the form of football that is the most popular where the word is used. Sports commonly called ''football'' include (known as ''soccer'' ...
itself is an oval ball, similar to the balls used in rugby or
Australian rules football Australian rules football, officially known as Australian football, or simply called "Aussie rules", "football Football is a family of team sport A team is a
_At_all_levels_of_play,_the_football_is_inflated_to__and_weighs_;NCAA_Rules_2011–2012,_p. 20.NFL_Rules_2012,_p. 3._beyond_that,_the_exact_dimensions_vary_slightly._In_professional_play_the_ball_has_a_long_axis_of_,_a_long_circumference_of_,_and_a_short_circumference_of_._In_college_and_high_school_play_the_ball_has_a_long_axis_of_,_a_long_circumference_of_,_and_a_short_circumference_of_.


_Duration_and_time_stoppages

Football_games_last_for_a_total_of_60_minutes_in_professional_and_college_play_and_are_divided_into_two_halves_of_30_minutes_and_four_quarters_of_15_minutes.NFL_Rules_2012,_p. 14.NCAA_Rules_2011–2012,_p. 45._High_school_football_games_are_48_minutes_in_length_with_two_halves_of_24_minutes_and_four_quarters_of_12_minutes.NFHS_Rules_2012,_pp. 38–39._The_two_halves_are_separated_by_a_
_period,_and_the_first_and_third_quarters_are_followed_by_a_short_break.NFHS_Rules_2012,_p. 39._Before_the_game_starts,_the_referee_and_each_team's_captain_(sports).html" "title="half-time.html" "title="roup (disambiguation), group of individuals (human or non-human) working ...
. At all levels of play, the football is inflated to and weighs ;NCAA Rules 2011–2012, p. 20.NFL Rules 2012, p. 3. beyond that, the exact dimensions vary slightly. In professional play the ball has a long axis of , a long circumference of , and a short circumference of . In college and high school play the ball has a long axis of , a long circumference of , and a short circumference of .


Duration and time stoppages

Football games last for a total of 60 minutes in professional and college play and are divided into two halves of 30 minutes and four quarters of 15 minutes.NFL Rules 2012, p. 14.NCAA Rules 2011–2012, p. 45. High school football games are 48 minutes in length with two halves of 24 minutes and four quarters of 12 minutes.NFHS Rules 2012, pp. 38–39. The two halves are separated by a half-time">halftime In several team sport A team sport includes any sport where individuals are organized into opposing sports team, teams which compete to win. Team members act together towards a shared objective. This can be done in a number of ways such a ...
period, and the first and third quarters are followed by a short break.NFHS Rules 2012, p. 39. Before the game starts, the referee and each team's captain (sports)">captain Captain is a title for the commander of a military unit, the commander of a ship, aeroplane, spacecraft, or other vessel, or the commander of a port, fire department or police department, election precinct, etc. The captain is a military rank in a ...
meet at midfield for a coin toss. The visiting team can call either "heads" or "tails"; the winner of the toss chooses whether to receive or kick off the ball or which goal they wish to defend. They can defer their choice until the second half. Unless the winning team decides to defer, the losing team chooses the option the winning team did not select—to receive, kick, or select a goal to defend to begin the second half. Most teams choose to receive or defer, because choosing to kick the ball to start the game allows the other team to choose which goal to defend. Teams switch goals following the first and third quarters. If a down is in progress when a quarter ends, play continues until the down is completed.NFL Rules 2012, pp. 14–18NCAA Rules 2011–2012, pp. 47–53.NFHS Rules 2012, pp. 38–45 Games last longer than their defined length due to play stoppages—the average NFL game lasts slightly over three hours. Time in a football game is measured by the game clock. An operator is responsible for starting, stopping and operating the game clock based on the direction of the appropriate
official An official is someone who holds an office (function or Mandate (politics), mandate, regardless whether it carries an actual Office, working space with it) in an organization or government and participates in the exercise of authority, (either th ...
.NCAA Rules 2011–2012, pp. 16, 41. A separate
play clock A play clock, also called a delay-of-game timer, is a countdown clock intended to speed up the pace of the game in gridiron football Gridiron football,delay of game :''For Association football, see Timewasting.'' :''For the administrative decision to cease play and resume at a later time and/or day, see Delay (game)''. Delay of game is an action in a sports game in which a player or team deliberately stalls ...

delay of game
infraction has been committed. If the play clock expires before the ball has been snapped or free-kicked, a delay of game foul is called on the offense. The play clock is set 25 seconds after certain administrative stoppages in play and to 40 seconds when play is proceeding without such stoppages.NCAA Rules 2011–2012, pp. 41, 46–47.NFHS Rules 2019.


Advancing the ball and downs

There are two main ways the offense can advance the ball:
running Running is a method of terrestrial locomotion Terrestrial locomotion has evolved Evolution is change in the heritable Heredity, also called inheritance or biological inheritance, is the passing on of Phenotypic trait, traits from ...
and passing. In a typical play, the center passes the ball backwards and between their legs to the quarterback in a process known as the snap. The quarterback then either hands the ball off to a back, throws the ball, or runs with it. The play ends when the player with the ball is tackled or goes out-of-bounds or a pass hits the ground without a player having caught it. A forward pass can be legally attempted only if the passer is behind the line of scrimmage; only one forward pass can be attempted per down. Like in rugby, players can also pass the ball backwards at any point during a play. In the NFL, a down also ends immediately if the runner's helmet comes off. The offense is given a series of four plays, known as downs. If the offense advances ten or more yards in the four downs, they are awarded a new set of four downs. If they fail to advance ten yards, possession of the football is turned over to the defense. In most situations, if the offense reaches their fourth down they will
punt Punt or punting may refer to: Boats *Punt (boat), a flat-bottomed boat with a square-cut bow developed on the River Thames *Falmouth Quay Punt, a small sailing vessel hired by ships anchored in Falmouth harbour *Norfolk Punt, a type of racing ding ...
the ball to the other team, which forces them to begin their drive from farther down the field; if they are in
field goal rangeField goal range is the part of the field in American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangula ...
, they might attempt to score a field goal instead. A group of officials, the chain crew, keeps track of both the downs and the distance measurements. On television, a yellow line is electronically superimposed on the field to show the first down line to the viewing audience.


Kicking

There are two categories of kicks in football: scrimmage kicks, which can be executed by the offensive team on any down from behind or on the line of scrimmage,NFL Rules 2012, p. 50.NCAA Rules 2011–2012, p. 34.NFHS Rules 2012, p. 32. and free kicks.NFL Rules 2012, p. 6.NCAA Rules 2011–2012, p. 30.NFHS Rules 2012, p. 27. The free kicks are the kickoff, which starts the first and third quarters and overtime and follows a try attempt or a successful field goal; the safety kick follows a safety.NFL Rules 2012, pp. 8–9.NFHS Rules 2012, pp. 31–32. On a kickoff, the ball is placed at the 35-yard line of the kicking team in professional and college play and at the 40-yard line in high school play. The ball may be drop-kicked or place-kicked. If a place kick is chosen, the ball can be placed on the ground or a tee; a holder may be used in either case. On a safety kick, the kicking team kicks the ball from their own 20-yard line. They can punt, drop-kick or place-kick the ball, but a tee may not be used in professional play. Any member of the receiving team may catch or advance the ball. The ball may be recovered by the kicking team once it has gone at least ten yards and has touched the ground or has been touched by any member of the receiving team.NFL Rules 2012, pp. 29–30.NCAA Rules 2011–2012, pp. 61–64.NFHS Rules 2012, pp. 15, 46, 52–53. The three types of scrimmage kicks are place kicks, drop kicks, and punts. Only place kicks and drop kicks can score points. The place kick is the standard method used to score points, because the pointy shape of the football makes it difficult to reliably drop kick. Once the ball has been kicked from a scrimmage kick, it can be advanced by the kicking team only if it is caught or recovered behind the line of scrimmage. If it is touched or recovered by the kicking team beyond this line, it becomes dead at the spot where it was touched.NFL Rules 2012, pp. 33–34, 50–53.NCAA Rules 2011–2012, pp. 55–56, 63–64.NFHS Rules 2012, pp. 49,  53–54. The kicking team is prohibited from interfering with the receiver's opportunity to catch the ball. The receiving team has the option of signaling for a
fair catch A fair catch is a feature of American football and several other football, codes of football, in which a player attempting to catch a ball kicked by the opposing team – either on a kickoff (gridiron football), kickoff or punt (gridiron football), ...
, which prohibits the defense from blocking into or tackling the receiver. The play ends as soon as the ball is caught and the ball may not be advanced.NFL Rules 2012, pp. 7, 54–55.NCAA Rules 2011–2012, pp. 30, 66–67.NFHS Rules 2012, pp. 27, 56.


Officials and fouls

Officials are responsible for enforcing game rules and monitoring the clock. All officials carry a
whistle A whistle is an instrument which produces sound from a stream of gas, most commonly air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large ...

whistle
and wear black-and-white striped shirts and black hats except for the referee, whose hat is white. Each carries a weighted yellow flag that is thrown to the ground to signal that a
foul Foul may refer to: __NOTOC__ In sports * Foul (sports), an unfair or illegal sports act, including: ** Foul (association football), in football (soccer) ** Professional foul, in football (soccer) or rugby ** Foul (basketball) * Foul ball, in baseba ...
has been called. An official who spots multiple fouls will throw their hat as a secondary signal. The seven officials (of a standard seven-man crew; lower levels of play up to the college level use fewer officials) on the field are each tasked with a different set of responsibilities: * The referee is positioned behind and to the side of the offensive backs. The referee is charged with oversight and control of the game and is the authority on the score, the down number, and any rule interpretations in discussions among the other officials. The referee announces all penalties and discusses the infraction with the offending team's captain, monitors for illegal hits against the quarterback, makes requests for first-down measurements, and notifies the head coach whenever a player is ejected. The referee positions themselves to the passing arm side of the quarterback. In most games, the referee is responsible for spotting the football prior to a play from scrimmage. * The umpire is positioned in the defensive backfield, except in the NFL, where the umpire is positioned lateral to the referee on the opposite side of the formation. The umpire watches play along the line of scrimmage to make sure that no more than 11 offensive players are on the field before the snap and that no offensive linemen are illegally downfield on pass plays. The umpire monitors contact between offensive and defensive linemen and calls most of the holding penalties. The umpire records the number of timeouts taken and the winner of the coin toss and the game score, assists the referee in situations involving possession of the ball close to the line of scrimmage, determines whether player equipment is legal, and dries wet balls prior to the snap if a game is played in rain. * The back judge is positioned deep in the defensive backfield, behind the umpire. The back judge ensures that the defensive team has no more than 11 players on the field and determines whether catches are legal, whether field goal or extra point attempts are good, and whether a
pass interference In American and Canadian Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are c ...
violation occurred. The back judge is also responsible for the play clock, the time between each play, when a visible play clock is not used. * The head linesman/down judge is positioned on one end of the line of scrimmage. The head linesman/down judge watches for any line-of-scrimmage and illegal use-of-hands violations and assists the line judge with illegal shift or illegal motion calls. The head linesman/down judge also rules on out-of-bounds calls that happen on their side of the field, oversees the chain crew and marks the forward progress of a runner when a play has been whistled dead. * The side judge is positioned twenty yards downfield of the head linesman. The side judge mainly duplicates the functions of the field judge. On field goal and extra point attempts, the side judge is positioned lateral to the umpire. * The line judge is positioned on the end of the line of scrimmage, opposite the head linesman. They supervise player substitutions, the line of scrimmage during punts, and game timing. The line judge notifies the referee when time has expired at the end of a quarter and notifies the head coach of the home team when five minutes remain for halftime. In the NFL, the line judge also alerts the referee when two minutes remain in the half. If the clock malfunctions or becomes inoperable, the line judge becomes the official timekeeper. * The field judge is positioned twenty yards downfield from the line judge. The field judge monitors and controls the
play clock A play clock, also called a delay-of-game timer, is a countdown clock intended to speed up the pace of the game in gridiron football Gridiron football,chain crew The chain crew at work during a Rutgers Scarlet Knights football game. The rear rod (right) marks the 21-yard line and the forward rod marks the 11. The "box" is behind the rear rod, to be visible to the press box across the field. In gridiron foot ...
, are responsible for moving the chains. The chains, consisting of two large sticks with a 10-yard-long chain between them, are used to measure for a first down. The chain crew stays on the sidelines during the game, but if requested by the officials they will briefly bring the chains on to the field to measure. A typical chain crew will have at least three people—two members of the chain crew will hold either of the two sticks, while a third will hold the down marker. The down marker, a large stick with a dial on it, is flipped after each play to indicate the current down and is typically moved to the approximate spot of the ball. The chain crew system has been used for over 100 years and is considered to be an accurate measure of distance, rarely subject to criticism from either side.


Safety and brain health

Football is a full-contact sport, and injuries are relatively common. Most injuries occur during training sessions, particularly ones that involve contact between players. To try to prevent injuries, players are required to wear a set of equipment. At a minimum players must wear a
football helmet The football helmet is a piece of American football protective equipment, protective equipment used mainly in gridiron football. It consists of a duroplast, hard plastic shell with thick padding on the inside, a Face mask (gridiron football), fac ...
and a set of
shoulder pads Shoulder pads are a piece of protective equipment used in many contact sports such as gridiron football, lacrosse, and ice hockey. Most modern shoulder pads consist of a Shock absorber, shock absorbing foam material with a hard plastic outer cove ...

shoulder pads
, but individual leagues may require additional padding such as thigh pads and guards, knee pads, chest protectors, and
mouthguard A mouthguard is a protective device for the mouth that covers the teeth and gums to prevent and reduce injury to the teeth A tooth (plural teeth) is a hard, calcification, calcified structure found in the jaws (or mouths) of many vertebrates ...

mouthguard
s.NFL Rules 2012, pp. 24–27.NCAA Rules 2011–2012, p.  22.NFHS Rules 2012, pp. 17–19. Most injuries occur in the lower extremities, particularly in the knee, but a significant number also affect the upper extremities. The most common types of injuries are strains,
sprain A sprain, also known as a torn ligament, is an injury resulting in the stretching or tearing of ligaments A ligament is the fibrous connective tissue Connective tissue is one of the four basic types of animal Animals (also called Meta ...
s,
bruise A bruise, also known as a contusion, is a type of hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding Bleeding, also known as a hemorrhage, haemorrhage, or simply blood loss, is blood Blood is a bod ...

bruise
s, fractures,
dislocations In materials science The interdisciplinary field of materials science, also commonly termed materials science and engineering, covers the design and discovery of new materials, particularly solids. The intellectual origins of materials scienc ...
, and
concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury A head injury is any injury that results in trauma to the skull The skull is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that con ...

concussion
s. Repeated
concussions A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration or b ...
(and possibly sub-concussive head impacts) can increase a person's risk in later life for CTE (
chronic traumatic encephalopathy Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease A neurodegenerative disease is caused by the progressive loss of structure or function of neuron A neuron or nerve cell is an membrane potential#Cell excitability, elec ...
) and mental health issues such as
dementia Dementia manifests as a set of related symptoms, which usually surface when the brain is damaged by injury or disease. The symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or ...
,
Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a chronic condition, long-term neurodegeneration, degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disea ...
, and
depression Depression may refer to: Mental health * Depression (mood), a state of low mood and aversion to activity * Mood disorders characterized by depression are commonly referred to as simply ''depression'', including: ** Dysthymia ** Major depressive ...
. Concussions are often caused by helmet-to-helmet or upper-body contact between opposing players, although helmets have prevented more serious injuries such as
skull fracture A skull fracture is a break in one or more of the eight bones that form the cranial portion of the skull The skull is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of the skeleton in most vertebrate an ...
s. Various programs are aiming to reduce concussions by reducing the frequency of helmet-to-helmet hits;
USA Football USA Football is the national governing body for amateur American football in the United States is the most popular . The has the highest and . In the United States the game is most often referred to as simply "". Organization in the Unit ...
's "Heads Up Football" program aims to reduce concussions in youth football by teaching coaches and players about the signs of a concussion, the proper way to wear football equipment and ensure it fits, and proper tackling methods that avoid helmet-to-helmet contact. However, a study in the ''Orthopaedic Journal of Sports Medicine'' found that Heads Up Football was ineffective; the same study noted that more extensive reforms implemented by
Pop Warner Little Scholars Pop Warner Little Scholars, commonly known simply as Pop Warner, is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized ...
and its member teams were effective in significantly reducing concussion rates. A 2018 study performed by the VA Boston Healthcare System and the
Boston University School of Medicine The Boston University School of Medicine (BUSM) is one of the graduate schools of Boston University. Founded in 1848, the medical school was the first institution in the world to formally educate female physicians. Originally known as the New E ...
found that tackle football before age 12 was correlated with earlier onset of symptoms of CTE, but not with symptom severity. More specifically, each year a player played tackle football under age 12 predicted earlier onset of cognitive, behavioral, and mood problems by an average of two and a half years.Age of First Exposure to Tackle Football and Chronic Traumatic Encephalopathy
, ''Annals of Neurology'', Michael L. Alosco PhD, Jesse Mez MD, MS, Yorghos Tripodis PhD, Patrick T. Kiernan BA, Bobak Abdolmohammadi BA, Lauren Murphy BA, Neil W. Kowall MD, Thor D. Stein MD, PhD, Bertrand Russell Huber MD, PhD, Lee E. Goldstein MD, PhD, Robert C. Cantu MD, Douglas I. Katz MD, Christine E. Chaisson MPH, Brett Martin MS, Todd M. Solomon PhD, Michael D. McClean ScD, Daniel H. Daneshvar MD, PhD, Christopher J. Nowinski PhD, Robert A. Stern PhD, Ann C. McKee MD, April 30, 2018.


Leagues and tournaments

The
National Football League The National Football League (NFL) is a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any s ...
(NFL) and the
National Collegiate Athletic Association The National Collegiate Athletic Association (NCAA) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and ...
(NCAA) are the most popular football leagues in the United States. The National Football League was founded in 1920 and has since become the largest and most popular sport in the United States. The NFL has the highest average attendance of any sporting league in the world, with an average attendance of 66,960 during the 2011 NFL season. The NFL championship game is called the Super Bowl, and is among the biggest events in club sports worldwide. It is played between the champions of the
National Football Conference The National Football Conference (NFC) is one of the two Athletic conference, conferences of the National Football League (NFL). The NFC and its counterpart, the American Football Conference (AFC), each contain 16 teams organized into 4 Division ...
(NFC) and the
American Football Conference The American Football Conference (AFC) is one of the two Athletic conference, conferences of the National Football League (NFL), the highest professional level of American football in the United States. This conference currently contains 16 team ...
(AFC), and its winner is awarded the
Vince Lombardi Trophy The Vince Lombardi Trophy is the trophy A trophy is a tangible, durable reminder of a specific achievement, and serves as a recognition or evidence of merit. Trophies are often awarded for sports, sporting events, from youth sports to professi ...
.
College football College football (french: football universitaire) is gridiron football Gridiron football,
is the third-most popular sport in the United States, behind professional baseball and professional football. The NCAA, the largest collegiate organization, is divided into three Divisions:
Division IDivision 1 and variants may refer to: Association football * Azadegan League, second tier of the men's senior football in Iran * Brisbane Premier League Division 1, second tier of the men's senior football in Brisbane, Queensland, Australia * Danis ...
, Division II and Division III. Division I football is further divided into two subdivisions: the
Football Bowl Subdivision The NCAA Division I Football Bowl Subdivision (FBS), formerly known as Division I-A, is the highest level of college football College football (french: football universitaire) is gridiron football Gridiron football,
(FBS) and the
Football Championship Subdivision NCAA Division I (D-I) is the highest level of intercollegiate athletics sanctioned by the National Collegiate Athletic Association The National Collegiate Athletic Association (NCAA) is a nonprofit organization that regulates student athle ...
(FCS). The champions of each level of play are determined through NCAA-sanctioned playoff systems; while the champion of Division I-FBS was historically determined by various polls and ranking systems, the subdivision adopted a four-team playoff system in 2014.
High school football High school football is gridiron football played by high school teams in the United States and Canada. It ranks among the most popular interscholastic sports in both countries, but its popularity is declining. According to the ''Washington Post ...
is the most popular sport in the United States played by boys; over 1.1 million boys participated in the sport from 2007 to 2008 according to a survey by the
National Federation of State High School Associations The National Federation of State High School Associations (NFHS) is the body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material o ...
(NFHS). The NFHS is the largest organization for high school football, with member associations in all
50 states The United States, United States of America is a federal republic consisting of 50 U.S. state, states, a Capital districts and territories#United States, federal district (Washington, D.C., the capital city of the United States), five major t ...
as well as the
District of Columbia ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument The Washington Monument is an obelisk within the National Mall The National Mall is a Landscape architecture, landscape ...
. USA Football is the governing body for youth and amateur football, and Pop Warner Little Scholars is the largest organization for youth football.


Other professional leagues

Several professional football leagues have been formed outside the auspices of the NFL. One such league, the XFL, is currently operating as of 2020.


Rival leagues

The most successful league to directly compete with the NFL was the American Football League (AFL), which existed from 1960 to 1969. The AFL became a significant rival in
1964 Events * January 1 January 1 or 1 January is the first day of the year in the Gregorian Calendar. There are 364 days remaining until the end of the year (365 in leap years). This day is known as New Year's Day since the day marks t ...
before signing a five-year, US$36 million television deal with NBC. AFL teams began signing NFL players to contracts, and the league's popularity grew to challenge that of the NFL. The two leagues merged in the 1970 season, and all the AFL teams joined the NFL. An earlier league, the
All-America Football Conference The All-America Football Conference (AAFC) was a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven pl ...
(AAFC), was in play from 1946 to 1949. After it had dissolved, two AAFC teams, the
Cleveland Browns The Cleveland Browns are a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any sport Spor ...
and the
San Francisco 49ers The San Francisco 49ers (also written as the San Francisco Forty Niners) are a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport ...
, became members of the NFL; another member, the
Baltimore Colts Baltimore ( , locally: ) is the most populous city The United Nations uses three definitions for what constitutes a city, as not all cities in all jurisdictions are classified using the same criteria. Cities may be defined as the city prope ...
joined the league, but folded after just a year in the NFL. Other attempts to start rival leagues since the AFL merged with the NFL in 1970 have been far less successful, as professional football salaries and the NFL's television contracts began to escalate out of the reach of competitors and the NFL covered more of the larger cities. The
World Football League The World Football League (WFL) was an American football league that played one full season in 1974 in sports, 1974 and most of its second in 1975 in sports, 1975. Although the league's proclaimed ambition was to bring American football onto a wo ...
(WFL) played for two seasons, in 1974 and 1975, but faced such severe monetary issues it could not pay its players. In its second and final season the WFL attempted to establish a stable credit rating, but the league disbanded before the season could be completed. The
United States Football League The United States Football League (USFL) was an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a r ...
(USFL) operated for three seasons from 1983 to 1985. Originally not intended as a rival league, the entry of owners who sought marquee talent and to challenge the NFL led to an escalation in salaries and ensuing financial losses. A subsequent US$1.5 billion antitrust lawsuit against the NFL was successful in court, but the league was awarded only $1 in damages, which was automatically tripled to $3 under antitrust law.


Complementary national leagues

The original XFL was created in 2001 by
Vince McMahon Vincent Kennedy McMahon (; born August 24, 1945) is an American professional wrestling Professional wrestling is a form of entertainment and performing art, which combines athletics with performance. It comprises of exhibitions, called ...

Vince McMahon
and lasted for only one season. Despite television contracts with NBC and
UPN The United Paramount Network (UPN) was an American broadcast Broadcasting is the distributionDistribution may refer to: Mathematics *Distribution (mathematics) Distributions, also known as Schwartz distributions or generalized func ...

UPN
, and high expectations, the XFL suffered from low quality of play and poor reception for its use of tawdry professional wrestling gimmicks, which caused initially high ratings and attendance to collapse. (The current XFL, also owned by McMahon, does not include those gimmicks.) The United Football League (UFL) began in
2009 2009 was designated as: *International Year of Astronomy 200px, Euro gold and silver commemorative coins (Austria)#2009 Coinage, International Year of Astronomy commemorative coin. The International Year of Astronomy (IYA2009) was a year-l ...
but folded after suspending its 2012 season amid declining interest and lack of major television coverage. The
Alliance of American Football The Alliance of American Football (AAF) was a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven play ...
lasted less than one season, unable to keep investors.


International play

American football leagues exist throughout the world, but the game has yet to achieve the international success and popularity of
baseball Baseball is a bat-and-ball gameBat-and-ball may refer to: *Bat-and-ball games Bat-and-ball games (or safe haven games) are field games played by two opposing teams, in which the action starts when the defending team throws a ball at ...

baseball
and
basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular court A court is any person or institution, often as a government institution, with the authority to Adjudication, ...

basketball
. It is not an
Olympic sport Olympic sports are contested in the Summer Olympic Games and Winter Olympic Games. The 2020 Summer Olympics included 33 sports; the 2022 Winter Olympics will include seven sports. Each Olympic sport is represented by an Sports governing body, in ...
, but it was a
demonstration sport A demonstration sport is a sport which is played to promote it, rather than as part of standard medal competition. This occurs most commonly during the Olympic Games The modern Olympic Games or Olympics (french: Jeux olympiques) are leadin ...
at the
1932 Summer Olympics The 1932 Summer Olympics, officially known as the Games of the X Olympiad, was an international multi-sport event that was held from July 30 to August 14, 1932, in Los Angeles Los Angeles ( ; xgf, Tovaangar; es, Los Ángeles, , ), co ...
. At the international level, Canada, Mexico, and Japan are considered to be second-tier, while Austria, Germany, and France would rank among a third tier. These countries rank far below the United States, which is dominant at the international level.
NFL Europa The World League of American Football (shortened to WLAF or World LeagueThe abbreviation "World League" was often used ifield signsads< ...
, the of the NFL, operated from 1991 to 1992 and then from 1995 to 2007. At the time of its closure, NFL Europa had five teams based in Germany and one in the Netherlands. In Germany, the
German Football League The German Football League (GFL) is an American football league in Germany and was formed in 1979. Playing rules are based on those of the American NCAA. In 1999, the league switched its name from ''American-Football-Bundesliga'' to ''German Fo ...
(GFL) has 16 teams and has operated for over 40 seasons, with the league's championship game, the
German Bowl The German Bowl is the annual national championship game in the sport of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of ...
, closing out each season. The league operates in a
promotion and relegation In sports league A sports league is a group of sports team A sports team is a group of individuals who play sport Sport pertains to any form of Competition, competitive physical activity or game that aims to use, maintain or improve p ...
structure with
German Football League 2 The German Football League 2 (GFL) is the second tier of American football in Germany, below the German Football League. Until 2007, the league was known as the ''2. Bundesliga''. League structure The ''GFL 2'', formerly the ''2. Bundesliga'', whi ...
(GFL2), which also has 16 teams. The
BIG6 European Football League The BIG6 European Football League (BIG6) is a European Cup style tournament for European American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport playe ...
functions as a continental championship for Europe. The competition is contested between the top six European teams. The
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed. The Guardian' and Telegraph' use Britain as a synonym for the United Kingdom. Some prefer to use Britain as shorth ...

United Kingdom
also operated several teams within NFL Europe during the League's tenure, the resulting rise in popularity of the sport brought the NFL back to the country in 2007 where they now hold the
NFL International Series File:NFL International Series 2010.jpg, 300px, Opening ceremony at Wembley Stadium before the Denver Broncos vs. San Francisco 49ers game in 2010 The NFL International Series is a series of American football games during the NFL regular season, N ...
in
London London is the capital Capital most commonly refers to: * Capital letter Letter case (or just case) is the distinction between the letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowerc ...

London
, currently consisting of four regular season games. The continuing interest and growth in both the sport and the series has led to the possible formation of a potential NFL franchise in London An American football league system already exists within the UK, the BAFANL, which has ran under various guises since 1983. It currently has 70 teams operating across the tiers of contact football in which teams aim to earn promotion to the Division above, with the Premier Division teams competing to win the
Britbowl The Britbowl is the championship game of the British American Football National League, and formerly the British American Football League (BAFL) in the United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly kn ...
, the annual British Football Bowl game that has been played since 1985. In 2007 the
British Universities American Football League The British Universities American Football League (BUAFL), is an American football league contested by university teams in the United Kingdom as part of the British Universities and Colleges Sport (BUCS) organisation. The league was formed by the ...
was formed. From 2008, the BUAFL was officially associated with the
National Football League The National Football League (NFL) is a professional American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes any s ...
(NFL), through its partner organisation NFL UK. In 2012, BUAFL's league and teams were absorbed into BUCS after American football became an official BUCS sport. Over the period 2007 to 2014, the BUAFL grew from 42 teams and 2,460 participants to 75 teams and over 4,100 people involved. American football federations are present in
Africa Africa is the world's second-largest and second-most populous continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', ...
,
the Americas The Americas (also collectively called America) is a landmass comprising the totality of North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to East and West. ''North' ...
,
Asia Asia () is Earth's largest and most populous continent, located primarily in the Eastern Hemisphere, Eastern and Northern Hemisphere, Northern Hemisphere of the Earth, Hemispheres. It shares the continental landmass of Eurasia with the cont ...
,
Europe Europe is a continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of scienc ...
and
Oceania Oceania (, , ) is a geographic region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Eart ...
; a total of 64 national football federations exist as of July 2012. The
International Federation of American Football The International Federation of American Football (IFAF) is the international governing body A governing body is a group of people that has the authority to exercise governance Governance is all the processes of interactions be they thro ...
(IFAF), an international governing body composed of continental federations, runs tournaments such as the
IFAF World Championship The IFAF World Championship of American Football (also known as the IFAF World Cup) is an international gridiron competition held every four years and contested by teams representing member nations. The competition is run by the International Fe ...
, the IFAF Women's World Championship, the IFAF U-19 World Championship and the Flag Football World Championship. The IFAF also organizes the annual International Bowl game. The IFAF has received provisional recognition from the
International Olympic Committee The International Olympic Committee (IOC; french: Comité international olympique, ''CIO'') is a non-governmental sports organisation based in Lausanne , neighboring_municipalities= Bottens Bottens is a municipalities of Switzerland, m ...
(IOC). Several major obstacles hinder the IFAF goal of achieving status as an Olympic sport. These include the predominant participation of men in international play and the short three-week Olympic schedule. Large team sizes are an additional difficulty, due to the Olympics' set limit of 10,500 athletes and coaches. American football also has an issue with a lack of global visibility.
Nigel Melville Nigel David Melville (born 6 January 1961) is a former England national rugby union team scrum half and captain and currently serves as Director of Professional Rugby for Rugby Football Union. Melville became the youngest player to captain Englan ...
, the CEO of
USA Rugby USA Rugby (officially the United States of America Rugby Football Union, Ltd.) is the national Sport governing body, governing body for the sport of rugby union in the United States. Its role is to serve as "the national governing body charged wi ...
, noted that "American football is recognized globally as a sport, but it's not played globally." To solve these concerns, major effort has been put into promoting
flag football Flag football is a variant of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American ...
, a modified version of American football, at the international level.


Popularity and cultural impact


United States

"Baseball is still called the national pastime, but football is by far the more popular sport in American society", according to ESPN.com's Sean McAdam. In a 2014 poll conducted by , professional football ranked as the most popular sport, and college football ranked third behind only professional football and baseball; 46% of participants ranked some form of the game as their favorite sport. Professional football has ranked as the most popular sport in the poll since 1985, when it surpassed baseball for the first time. Professional football is most popular among those who live in the eastern United States and rural areas, while college football is most popular in the southern United States and among people with graduate and post-graduate degrees. Football is also the most-played sport by high school and college athletes in the United States. In a 2012 study, the NCAA estimated there were around 1.1 million high school football players and nearly 70,000 college football players in the United States; in comparison, the second-most played sport, basketball, had around 1 million participants in high school and 34,000 in college. The Super Bowl is the most popular single-day sporting event in the United States, and is among the biggest club sporting events in the world in terms of TV viewership. The NFL makes approximately $10 billion annually. Super Bowl games account for seven of the top eight most-watched broadcasts in American history;
Super Bowl XLIX Super Bowl XLIX was an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American footba ...
, played on February 1, 2015, was watched by a record 114.4 million Americans. American football also plays a significant role in American culture. The day on which the Super Bowl is held is considered a ''de facto'' national holiday, and in parts of the country like
Texas Texas (, ; Spanish Spanish may refer to: * Items from or related to Spain: **Spaniards, a nation and ethnic group indigenous to Spain **Spanish language **Spanish cuisine Other places * Spanish, Ontario, Canada * Spanish River (disambigu ...

Texas
, the sport has been compared to a religion. Football is also linked to other holidays; New Year's Day is traditionally the date for several college football bowl games, including the Rose Bowl. However, if New Year's Day is on a Sunday, the bowl games are moved to another date so as not to conflict with the typical NFL Sunday schedule.
Thanksgiving Thanksgiving is a national holiday A holiday is a day set aside by custom Custom may refer to: Sense: Customary * Convention (norm), a set of agreed, stipulated or generally accepted rules, norms, standards or criteria, often taking th ...
football Football is a family of s that involve, to varying degrees, a to score a . Unqualified, normally means the form of football that is the most popular where the word is used. Sports commonly called ''football'' include (known as ''soccer'' ...
is an American tradition, hosting many high school, college, and professional games. Steve Deace of ''
USA Today ''USA Today'' (stylized in all uppercase) is an American daily middle-market newspaper A middle-market newspaper is a newspaper that caters to readers who like entertainment as well as the coverage of important news events. Middle-market sta ...
'' wrote that Americans are passionate about football "because it embodies everything we love about
American exceptionalism American exceptionalism is the theory that the United States is inherently different from other nations. Implicit rules such as playing through pain and sacrificing for the better of the team are promoted in football culture. The safety of the sport has also sparked national controversy in
American popular culture The culture of the United States of America is primarily of Western origin, but is influenced by a multicultural ethos that includes African, Native American, Asian, Pacific Island This is a list of islands in the Pacific Ocean, collecti ...
. It is often received as "overly aggressive", and defamiliarized in popular culture. The 2015 film ''
Concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury A head injury is any injury that results in trauma to the skull The skull is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that con ...
'' aimed to shed light on the sport's safety, specifically in the NFL by having
Will Smith Willard Carroll Smith Jr. (born September 25, 1968) is an American actor, rapper, and film producer. Smith has been nominated for five Golden Globe Awards The Golden Globe Awards are accolades bestowed by the 87 members of the Hollywo ...

Will Smith
portray Dr. Bennet Omalu, a
neuropathologist Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the clinica ...
who was the first to discover and publish findings of chronic traumatic encephalopathy or CTE.


Other countries

In Canada, the game has a significant following. According to a 2013 poll, 21% of respondents said they followed the NFL "very closely" or "fairly closely", making it the third-most followed league behind the
National Hockey League The National Hockey League (NHL; french: Ligue nationale de hockey—LNH) is a professional ice hockey sports league, league in North America comprising 32 teams—25 in the United States and 7 in Canada. It is considered to be the premier pr ...
(NHL) and
Canadian Football League The Canadian Football League (CFL; french: Ligue canadienne de football, LCF, links=no) is a professional sports league A sports league is a group of sports team A sports team is a group of individuals who play sport Sport pertains ...
(CFL). American football also has a long history in Mexico, which was introduced to the sport in 1896. It was the second-most popular sport in Mexico in the 1950s, with the game being particularly popular in colleges. The ''
Los Angeles Times The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper A newspaper is a containing written and is often typed in black ink with a white or gray background. Newspapers can cover a wide variety of fields such as , ...

Los Angeles Times
'' notes the NFL claims over 16 million fans in Mexico, which places the country third behind the U.S. and Canada. American football is played in Mexico both professionally and as part of the college sports system. A professional league, the
Liga de Fútbol Americano Profesional The Professional American Football League ( or ''LFA'') is a professional American football spring Sports league, league in Mexico, founded in 2016. Starting with four teams, the LFA has since expanded to eight members as of 2019. The championshi ...
(LFA), was founded in 2016. Japan was introduced to the sport in 1934 by Paul Rusch, a teacher and Christian missionary who helped to establish football teams at three universities in Tokyo. Play was halted during World War II, but the sport began growing in popularity again after the war. , there are more than 400 high school football teams in Japan, with over 15,000 participants, and over 100 teams play in the Kantoh Collegiate Football Association (KCFA). The college champion plays the champion of the
X-League The X-League () is the top-level American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular Amer ...
(a semi-professional league where teams are financed by corporations) in the
Rice Bowl The Japan Championship Rice Bowl is an annual American football national championship game held in Japan every January 3 that determines the champion of the X-League. Prior to the 2022 edition, the game matched up the champions of the Japan X Bowl ...
to determine Japan's national champion. Europe is a major target for the expansion of the game by football organizers. In the United Kingdom in the 1980s, the sport was popular, with the 1986 Super Bowl being watched by over four million people (about 1 out of every 14 Britons). Its popularity faded during the 1990s, coinciding with the establishment of the
Premier League The Premier League, often referred to as the English Premier League or the EPL (legal name: The Football Association Premier League Limited), is the top level of the English football league system The English football league system, als ...
—top level of the
English football league system The English football league system, also known as the football pyramid, is a series of interconnected leagues for men's association football Association football, more commonly known as simply football or soccer, is a team sport played w ...
. According to
BBC America BBC America is an American basic cable Cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, ligh ...

BBC America
, there is a "social stigma" surrounding American football in the UK, with many Brits feeling the sport has no right to call itself "football" due to the lack of emphasis on kicking. Nonetheless, the sport has retained a following in the United Kingdom; the NFL operates a media network in the country, and since 2007 has hosted the
NFL International Series File:NFL International Series 2010.jpg, 300px, Opening ceremony at Wembley Stadium before the Denver Broncos vs. San Francisco 49ers game in 2010 The NFL International Series is a series of American football games during the NFL regular season, N ...
in London. Super Bowl viewership has also rebounded, with over 4.4 million Britons watching
Super Bowl XLVI Super Bowl XLVI was an American football game between the National Football Conference (NFC) champion 2011 New York Giants season, New York Giants and the American Football Conference (AFC) champion 2011 New England Patriots season, New England ...
. The sport is played in European countries like Switzerland, which has American football clubs in every major city, and Germany, where the sport has around 45,000 registered amateur players. In
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At 8.5 million square kilometers (3.2 million square miles) and with over 211 mill ...
, football is a growing sport. It was generally unknown there until the 1980s when a small group of players began playing on
Copacabana Beach wave pattern at Copacabana beach Image:Hotel copacabana palace.jpg, The Copacabana Palace, Copacabana Palace Hotel Copacabana () is a ''bairro'' (neighbourhood) located in the Rio de Janeiro#South Zone, South Zone of the city of Rio de J ...

Copacabana Beach
in
Rio de Janeiro Rio de Janeiro (; ), or simply Rio, is the List of largest cities in Brazil, second-most populous city in Brazil and the Largest cities in the Americas, sixth-most populous in the Americas. Rio de Janeiro is the capital of the Rio de Janeiro (s ...

Rio de Janeiro
. The sport grew gradually with 700 amateur players registering within 20 years. Games were played on the beach with modified rules and without the traditional football equipment due to its lack of availability in Brazil. Eventually, a tournament, the Carioca championship, was founded, with the championship Carioca Bowl played to determine a league champion. The country saw its first full-pad game of football in October 2008. According to ''
The Rio Times ''The Rio Times'' is an English Language, English-language newspaper and news and features website based in Rio de Janeiro, Brazil and one of the biggest newspapers in English in all of Latin America, with a reach twice as large as the second-plac ...
'', the sport is one of the fastest-growing sports in Brazil and is almost as commonly played as soccer on the beaches of Copacabana and
Botafogo Botafogo (local/standard alternative Brazilian Portuguese pronunciation: ) is a beachfront neighborhood ('' bairro'') in Rio de Janeiro, Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the ...

Botafogo
. Football in Brazil is governed by the Confederação Brasileira de Futebol Americano (CBFA), which had over 5,000 registered players as of November 2013. The sport's increase in popularity has been attributed to games aired on
ESPN ESPN (originally an initialism for Entertainment and Sports Programming Network) is an American multinational basic cable Cable television Cable television is a system of delivering television programming to consumers via radio frequen ...

ESPN
, which began airing in Brazil in 1992 with Portuguese commentary. The popularity and "easy accessibility" of non-contact versions of the sport in Brazil has led to a rise in participation by female players. According to ESPN, the American football audience in Brazil increased 800% between 2013 and 2016. The network, along with
Esporte Interativo Esporte Interativo (EI) ( en, Interactive Sport) is a subsidiary of WarnerMedia Warner Media, LLC, doing business as WarnerMedia, is an American multinational mass media and entertainment Entertainment is a form of activity that holds t ...

Esporte Interativo
, airs games there on cable television. Football is often associated in Brazil as being the sport of supermodel
Gisele Bündchen Gisele Caroline Bündchen (, , born 20 July 1980) is a Brazilian model, activist, and businesswoman. Since 2001, Bündchen has been one of the highest-paid models in the world. In 2007, she was the 16th richest woman in the entertainment in ...
's husband
Tom Brady Thomas Edward Patrick Brady Jr. (born August 3, 1977) is an American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport A team sport includes a ...

Tom Brady
. The NFL has expressed interest in having games in the country, and the Super Bowl has become a widely watched event in Brazil at bars and
movie theater A movie theater (American English), cinema (British English), or cinema hall (Indian English), also known as a picture house, the pictures, picture theater, the silver screen, or the movies, is a building that contains auditoria for viewing ...

movie theater
s.


Variations and related sports

Canadian football Canadian football () is a sport Sport pertains to any form of competitive Competition is a rivalry A rivalry is the state of two people or groups engaging in a lasting competitive relationship. Rivalry is the "against each other ...

Canadian football
, the predominant form of football in Canada, is closely related to American football—both sports developed from rugby and are considered to be the chief variants of gridiron football. Although both games share a similar set of rules, there are several key rule differences: for example, in Canadian football the field measures , including two 20-yard end zones (for a distance between goal lines of 110 yards), teams have three downs instead of four, there are twelve players on each side instead of eleven, fair catches are not allowed, and a
rouge Rouge is the French word for "red" and may refer to: Compounds * Rouge (cosmetics), a cosmetic used to color the cheeks and emphasize the cheekbones * Jeweler's rouge or iron(III) oxide * Rouging, a form of corrosion applicable to stainless st ...
, worth a single point is scored if the offensive team kicks the ball out of the defense's end zone. The Canadian Football League (CFL) is the major Canadian league and is the second-most popular sporting league in Canada, behind the National Hockey League. The NFL and CFL had a formal working relationship from 1997 to 2006. The CFL has a strategic partnership with two American football leagues, the German Football League (GFL) and the Liga de Futbol Americano Profesional (LFA). The Canadian rules were developed separately from the American game. Indoor football leagues constitute what ''
The New York Times ''The New York Times'' is an American daily newspaper based in New York City with a worldwide readership. Founded in 1851, the ''Times'' has since won List of Pulitzer Prizes awarded to The New York Times, 132 Pulitzer Prizes, the most of a ...

The New York Times
'' writer Mike Tanier described as the "most minor of minor leagues." Leagues are unstable, with franchises regularly moving from one league to another or merging with other teams, and teams or entire leagues dissolving completely; games are only attended by a small number of fans, and most players are
semi-professional Semi-professional sports are sport Sport pertains to any form of competitive Competition is a rivalry A rivalry is the state of two people or groups engaging in a lasting competitive relationship. Rivalry is the "against each other ...
athletes. The
Indoor Football League The Indoor Football League (IFL) is a professional indoor American football league created in 2008 out of the merger between the Intense Football League and United Indoor Football. It has one of the largest number of currently active teams among ...
is an example of a prominent indoor league. The
Arena Football League The Arena Football League (AFL) was a professional arena football, indoor American football league in the United States. It was founded in 1987 Arena Football League season, 1987, making it the third longest-running professional football league ...
, which was founded in 1987 and ceased operations in 2019, was one of the longest-lived indoor football leagues. In 2004, the league was called "America's fifth major sport" by ''
ESPN The Magazine ''ESPN The Magazine'' was an American monthly sports magazine A magazine is a periodical literature, periodical publication which is printing, printed in Coated paper, gloss-coated and Paint sheen, matte paper. Magazines are generally publish ...
''. There are several non-contact variants of football like
Flag football Flag football is a variant of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American ...
. In flag football the ballcarrier is not tackled; instead, defenders aim to pull a flag tied around their waist. Another variant, touch football, simply requires the ballcarrier to be touched to be considered downed. Depending on the rules used, a game of touch football may require the player be touched with either one or two hands to be considered down.


See also

*
American football strategy Strategy forms a major part of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American ...
*
Comparison of American football and rugby union A comparison of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American football field ...
*
Comparison of American football and rugby league A comparison between American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American football fi ...
*
Fantasy football (American) Fantasy football is a game in which the participants serve as general managers of Virtual reality, virtual professional American football teams. The competitors select their rosters by participating in a draft (sports), draft in which all relevan ...
*
List of American football players Lists of American football American football, referred to simply as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular American football field, field wi ...
*
List of American football stadiums by capacity The following is an incomplete list of current American football stadiums ranked by capacity. The list contains the home stadiums of all 32 professional teams playing in the NFL as well as the largest stadiums used by college football Colle ...
*
List of leagues of American and Canadian football This is a list of current and defunct leagues of American football and Canadian football. Leagues in North America Current professional leagues in North America Professional outdoor leagues ''Major'' * National Football League (NFL), 1920– ::O ...
* Steroid use in American football


Notes


Footnotes


References

* * * * * * * *


Further reading

*
Football: Great Writing About the National Sport
', edited by John Schulian; 2014 (New York:
Library of America The Library of America (LOA) is a nonprofit A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collective, public or so ...
)


External links

*
National Football League

International Federation of American Football

NFL 360, an introductory website to football rules

Excerpts of a 1903 football game between the University of Chicago and University of Michigan
{{DEFAULTSORT:American Football 1869 introductions American culture Ball games Football codes Sports originating in the United States Gridiron football