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Troitsky Line
The two knights endgame is a chess endgame with a king and two knights versus a king. In contrast to a king and two bishops (on opposite-colored squares), or a bishop and a knight, a king and two knights cannot checkmate against a lone king (however, the superior side can force stalemate). Although there are checkmate positions, a king and two knights cannot them against proper, relatively easy defense. Although the king and two knights cannot checkmate of the lone king, there are positions in which the king and two knights can force checkmate against a king and some additional material. The extra material of the defending side provides moves that prevent the defending king from being stalematedor, less commonly, the extra material obstructs the defending king from escaping check. The winning chances with two knights are insignificant except against a few pawns. These positions were studied extensively by A. A. Troitsky, who discovered the Troitsky line, a line on or behind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chess Kll45
Chess is a board game for two players. It is an abstract strategy game that involves no hidden information and no elements of chance. It is played on a square board consisting of 64 squares arranged in an 8×8 grid. The players, referred to as "White" and "Black", each control sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns, with each type of piece having a different pattern of movement. An enemy piece may be captured (removed from the board) by moving one's own piece onto the square it occupies. The object of the game is to " checkmate" (threaten with inescapable capture) the enemy king. There are also several ways a game can end in a draw. The recorded history of chess goes back to at least the emergence of chaturanga—also thought to be an ancestor to similar games like and —in seventh-century India. After its introduction in Persia, it spread to the Arab world and then to Europe. The modern rules of chess emerged in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promotion (chess)
In chess, promotion is the replacement of a pawn with a new piece when the pawn is moved to its . The player replaces the pawn immediately with a queen, rook, bishop, or knight of the same . The new piece does not have to be a previously captured piece. Promotion is mandatory when moving to the last rank; the pawn cannot remain as a pawn. Promotion to a queen is known as ''queening''; promotion to any other piece is known as '' underpromotion''. Promotion is almost always to a queen, as it is the most powerful piece. Underpromotion might be done for various reasons, such as to avoid stalemate or for tactical reasons related to the knight's unique movement pattern. Promotion or the threat of it often decides the result in an endgame. Rules When a pawn is promoted, it is removed from the board, and the new piece is placed on the square the pawn moved to. Any piece may be promoted to regardless of whether it has been captured. Consequently, a player might have two or more quee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Nunn
John Denis Martin Nunn (born 25 April 1955) is an English chess grandmaster, a three-time world champion in chess problem solving, a chess writer and publisher, and a mathematician. He is one of England's strongest chess players and was formerly in the world's top ten. Education and early life Nunn was born in London. As a junior, he showed a prodigious talent for chess and in 1967, at 12 years of age, he won the British under-14 Championship. At 14, he was London Under-18 Champion for the 1969–70 season and less than a year later, at just 15 years of age, he proceeded to Oriel College, Oxford, to read Mathematics. At the time, Nunn was Oxford's youngest undergraduate since Cardinal Wolsey in 1520. Graduating in 1973, he went on to gain a Doctor of Philosophy degree in 1978 with a thesis on finite H-spaces, supervised by John Hubbuck. In 1978, Nunn spent a year teaching Mathematics at Maidstone Grammar School, before returning to Oxford as a mathematics lecturer until 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fifty-move Rule
The fifty-move rule in chess states that a player can claim a draw if no has been made and no pawn has been moved in the last fifty moves (where a "move" consists of a player completing a turn followed by the opponent completing a turn). The purpose of this rule is to prevent a player with no chance of winning from obstinately continuing to play indefinitely or seeking to win by tiring the opponent. Chess positions with only a few pieces can be " solved", that is, the outcome of best play for both sides can be determined by exhaustive analysis; if the outcome is a win for one side or the other (rather than a draw), it is of interest to know whether the defending side can hold out long enough to invoke the fifty-move rule. The simplest common endings, called the basic checkmates, such as king and queen versus king, can all be won in well under 50 moves. However, in the 20th century it was discovered that certain endgame positions are winnable but require more than 50 moves (wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pawn (chess)
The pawn (♙, ♟) is the most numerous and weakest piece in the game of chess. It may move one square directly forward, it may move two squares directly forward on its first move, and it may capture one square diagonally forward. Each player begins a game with eight pawns, one on each square of their second . The white pawns start on a2 through h2; the black pawns start on a7 through h7. Individual pawns are referred to by the on which they stand. For example, one speaks of "White's f-pawn" or "Black's b-pawn". Alternatively, they can be referred to by the piece which stood on that file at the beginning of the game, e.g. "White's king bishop's pawn" or "Black's queen knight's pawn". It is also common to refer to a ''rook's pawn'', meaning any pawn on the a- or h-files, a ''knight's pawn'' (on the b- or g-files), a ''bishop's pawn'' (on the c- or f-files), a ''queen's pawn'' (on the d-file), a ''king's pawn'' (on the e-file), and a ''central pawn'' (on the d- or e-files). The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tempo (chess)
In chess and other chess-like games, a tempo (from ) is a "turn" or single move (a half-move or ply made either by White or Black). When a player achieves a desired result in one fewer move, the player is said to "gain a tempo"; conversely, when a player takes one more move than necessary, the player is said to "lose a tempo". Similarly, when a player forces their opponent to make moves not according to their initial plan, one is said to "gain tempo" because the opponent is wasting moves. A move that gains a tempo is often called "a move with tempo". A simple example of losing a tempo may be moving a rook from the h1-square to h5 and from there to h8 in the first diagram; simply moving from h1 to h8 would have achieved the same result with a tempo to spare. However, such maneuvers do not always lose a tempo—the rook on h5 may make some threat which needs to be responded to. In this case, since both players have "lost" a tempo, the net result in terms of time is nil, but the cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chess Pdl45
Chess is a board game for two players. It is an abstract strategy game that involves no hidden information and no elements of chance. It is played on a square board consisting of 64 squares arranged in an 8×8 grid. The players, referred to as "White" and "Black", each control sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns, with each type of piece having a different pattern of movement. An enemy piece may be captured (removed from the board) by moving one's own piece onto the square it occupies. The object of the game is to "checkmate" (threaten with inescapable capture) the enemy king. There are also several ways a game can end in a draw. The recorded history of chess goes back to at least the emergence of chaturanga—also thought to be an ancestor to similar games like and —in seventh-century India. After its introduction in Persia, it spread to the Arab world and then to Europe. The modern rules of chess emerged in Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrograde Analysis
In chess problems, retrograde analysis is a technique employed to determine which moves were played leading up to a given position. While this technique is rarely needed for solving ordinary chess problems, there is a whole subgenre of chess problems in which it is an important part; such problems are known as ''retros''. Retros may ask, for example, for a mate in two, but the main puzzle is in explaining the history of the position. This may be important to determine, for example, if castling is disallowed or an ''en passant'' capture is possible. Other problems may ask specific questions relating to the history of the position, such as, "Is the bishop on c1 promoted?". This is essentially a matter of logical reasoning, with high appeal for puzzle enthusiasts. Sometimes it is necessary to determine if a particular position is legal, with "legal" meaning that it could be reached by a series of legal moves, no matter how illogical. Another important branch of retrograde analysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viktor Korchnoi
Viktor Lvovich Korchnoi (, ; 23 March 1931 – 6 June 2016) was a Soviet (before 1976) and Swiss (after 1980) chess grandmaster (GM) and chess writer. He is considered one of the strongest players never to have become World Chess Champion. Born in Leningrad, Korchnoi defected to the Netherlands in 1976, and resided in Switzerland from 1978, becoming a Swiss citizen. Korchnoi played four matches against GM Anatoly Karpov, three of which were official. In 1974, Korchnoi lost to Karpov in the Candidates Tournament 1974, Candidates Tournament final. After GM Bobby Fischer declined to defend his title against Karpov, Karpov was declared World Chess Championship 1975, World Champion in 1975. In World Chess Championship 1978, 1978 and World Chess Championship 1981, 1981, Korchnoi won consecutive Candidates cycles and qualified to challenge Karpov for the World Chess Championship, but lost both matches. The two players also played a drawn training match of six games in 1971. Korchnoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatoly Karpov
Anatoly Yevgenyevich Karpov (, ; born May 23, 1951) is a Russian and former Soviet Grandmaster (chess), chess grandmaster, former World Chess Championship, World Chess Champion, and politician. He was the 12th World Chess Champion from 1975 to 1985, a three-time FIDE World Champion (1993, 1996, 1998), twice World Chess champion as a member of the USSR team (1985, 1989), and a six-time winner of Chess Olympiad, Chess Olympiads as a member of the USSR team (1972, 1974, 1980, 1982, 1986, 1988). The International Association of Chess Press awarded him nine Chess Oscars (1973–77, 1979, 1980, 1981, 1984). Karpov's chess tournament successes include over 160 first-place finishes. He had a peak Elo rating system, Elo rating of 2780, and his 102 total months world number one is the third-longest of all time, behind Magnus Carlsen and Garry Kasparov. Karpov is also an elected Member of the State Duma in Russia. Since 2006, he has chaired the Commission for Ecological Safety and Envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Chess Championship 1981
The 1981 World Chess Championship was played between Anatoly Karpov and Viktor Korchnoi in Merano, Italy from October 1 to November 19, 1981. Karpov won with six wins against two, with 10 draws. The two players had already played against each other in the World Chess Championship match 1978 in the Philippines, when Karpov also won. 1979 Interzonal tournaments Two Interzonals were held in 1979, one in Riga and the other in Rio de Janeiro. : The Riga interzonal was won in dominant fashion by Tal, who went through the tournament undefeated ahead of Polugaevsky. They were joined in the Candidates Tournament by Adorján, whose better tie-break score in the main tournament put him ahead of Ribli, after the two drew a playoff in Budapest 3-3. The game between Gruenfeld and Bouaziz was not played, as part of the Arab boycott of Israeli sportspeople. Bouaziz forfeited and Gruenfeld received a point. : The Interzonal in Rio saw Portisch, Petrosian and Hübner share first pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threefold Repetition
In chess, the threefold repetition rule states that a player may claim a draw if the same position occurs three times during the game. The rule is also known as repetition of position and, in the USCF rules, as triple occurrence of position.Article 14K.2 in Two positions are by definition "the same" if pieces of the same type and color occupy the same squares, the same player has the move, the remaining castling rights are the same and the possibility to capture ''en passant'' is the same. The repeated positions need not occur in succession. The game is not automatically drawn if a position occurs for the third time – one of the players, on their turn, must claim the draw with the arbiter. The claim must be made either before making the move which will produce the third repetition, or after the opponent has made a move producing a third repetition. By contrast, the fivefold repetition rule requires the arbiter to intervene and declare the game drawn if the same position occurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
