baseball Baseball is a bat-and-ball games, bat-and-ball sport played between two team sport, teams of nine players each, taking turns batting (baseball), batting and Fielding (baseball), fielding. The game occurs over the course of several Pitch ...

, the statistic innings pitched (IP) is the number of

inning In baseball, softball, and similar games, an inning is the basic unit of play, consisting of two halves or frames, the "top" (first half) and the "bottom" (second half). In each half, one team bats until three outs are made, with the other tea ...

s a

pitcher In baseball, the pitcher is the player who throws ("Pitch (baseball), pitches") the Baseball (ball), baseball from the pitcher's mound toward the catcher to begin each play, with the goal of out (baseball), retiring a batter (baseball), batter, ...

has completed, measured by the number of batters and baserunners that have been put out while the pitcher is on the pitching mound in a game. Three outs made is equal to one inning pitched. One out counts as one-third of an inning, and two outs as two-thirds of an inning. Sometimes, the statistic is written 34.1, 72.2, or 91.0, for example, to represent innings, innings, and 91 innings exactly, respectively. Runners

left on base This is an alphabetical list of selected unofficial and specialized terms, phrases, and other jargon used in baseball, along with their definitions, including illustrative examples for many entries. 0–9 0 :"Oh and ..." See #count, coun ...

by a pitcher are not counted in determining innings pitched. It is possible for a pitcher to enter a game, give up several hits and possibly even several runs, and be removed before achieving any outs, thereby recording a total of zero innings pitched. Alternatively, it is possible for a pitcher to enter a situation where there are two runners on base and no outs. He could throw one pitch that results in a triple play, and for that one pitch, he would be credited with a full-inning pitched.

Decline

Major League Baseball Major League Baseball (MLB) is a professional baseball league composed of 30 teams, divided equally between the National League (baseball), National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. MLB i ...

, the only active players in the top 100 all-time at the end of the season were Tom Glavine (ranked 30th with IP),

Randy Johnson Randall David Johnson (born September 10, 1963), nicknamed, "the Big Unit," is an American former professional baseball pitcher who played 22 seasons in Major League Baseball (1988–2009) for six teams, primarily the Seattle Mariners and Arizo ...

(ranked 38th with ),

Jamie Moyer Jamie Moyer (born November 18, 1962) is an American former professional baseball pitcher. Over his 25-year career in Major League Baseball (MLB), Moyer pitched for the Chicago Cubs, Texas Rangers (baseball), Texas Rangers, St. Louis Cardinals, Ba ...

(ranked 45th with ) and

John Smoltz John Andrew Smoltz (born May 15, 1967), nicknamed "Smoltzie" and "Marmaduke", is an American former baseball pitcher who played 21 seasons in Major League Baseball from 1988 to 2009, all but the last year with the Atlanta Braves. An eight-time Ma ...

(ranked 74th with 3473). By the end of the season, only two active players were in the top 100 all-time: CC Sabathia (ranked 73rd with 3470), and Bartolo Colón (ranked 74th with ). This is because over time, innings pitched have declined. Several factors are responsible for this decline: *From 1876 to 1892, pitchers threw from fifty feet and exerted less stress on their arms (also pitchers often threw underhand in this era). In this era, season totals of 600 innings pitched were not uncommon. *In 1893, the mound (the pitching rubber, to be more precise) was moved back to the current distance of sixty feet, six inches. However, they still often threw 400 innings in a season. This was because the

home run In baseball, a home run (abbreviated HR) is scored when the Baseball (ball), ball is hit in such a way that the batting (baseball), batter is able to circle the bases and reach home plate safe (baseball), safely in one play without any error ( ...

was far less common and pitchers often conserved arm strength throughout the game. *From 1920 to the 1980s, the four-man pitching rotation was well established. Pitchers could no longer throw 400 innings in a season, as the

meant a run could be scored at any time. The league leader in innings pitched often threw somewhat more than 300 innings. Occasionally, innings pitched would spike, as in the early 1970s, when Wilbur Wood pitched innings in and then innings in . *From the 1980s to the present, the four-man rotation was replaced with the five-man rotation, with a weak fifth man who would often be skipped on off days. Also, managers starting using their

bullpen In baseball, the bullpen (or simply the pen) is the area where relief pitchers warm up before entering a game. A team's roster of relief pitchers is also metonymically referred to as "the bullpen". These pitchers usually wait in the bullpen if ...

s more and more, accelerating the decline in innings pitched. As of the start of the 2022 season no pitcher has thrown 250 innings since Justin Verlander in 2011.

Records

All-time leaders

Single-season leaders

Source:

References

External links

Career Leaders & Records for Innings Pitched
at Baseball-Reference.com {{DEFAULTSORT:Innings Pitched Pitching statistics