In chess and some other abstract strategy games, the threefold repetition rule (also known as repetition of position) states that a player can claim a draw if the same position occurs three times, or will occur after their next move, with the same player to move. The repeated positions need not occur in succession. The idea behind the rule is that if the position is repeated three times, no progress is being made.
In chess, in order for a position to be considered the same, each player must have the same set of legal moves each time, including the possible rights to castle and capture en passant. Positions are considered the same if the same type of piece is on a given square. So, for instance, if a player has two knights and the knights are on the same squares, it does not matter if the positions of the two knights have been exchanged. The game is not automatically drawn if a position occurs for the third time – one of the players, on their turn to move, must claim the draw with the arbiter.
In shogi, a fourfold repetition (千日手 sennichite) is required to end in a draw. Each player must have the same pieces in hand as well as the same position on the board. The result is a draw unless one player is giving perpetual check; in that case, that player loses.
|
| This article uses algebraic notation to describe chess moves. |
The relevant rule in the FIDE laws of chess is 9.2, which reads:
While the rule does not require that the position occur thrice on nearly consecutive moves, it happens this way very often in practice, typically with one of the kings being put into perpetual check. The intermediate positions and moves do not matter – they can be the same or different. The rule applies to positions, not moves.
Draws by this method used to be uncommon (Brace 1977:236).
The seventeenth,[1] eighteenth,[2] and twentieth[3] games of the 1972 World Championship match between Bobby Fischer and Boris Spassky were declared draws because of threefold repetition, although the twentieth game was an incorrect claim (see #Incorrect claims below).
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
In the third game[4] of the 1971 Candidates Final Match between Bobby Fischer and Tigran Petrosian, Petrosian (with a better position) accidentally allowed a position to be repeated three times (see diagram). Play continued:
and then Fischer wrote his next move
on his scoresheet, which is the third appearance of the position with Black to move, and he claimed a draw.[5] At first Petrosian was not aware of what was going on. Incidentally, this was the first time a draw by threefold repetition had been claimed in his career (Plisetsky & Voronkov 2005:283–84), (Kasparov 2004:422–23), (Byrne 1971:682). This also illustrates that the intermediate moves do not need to be the same – just the positions.
Players sometimes repeat a position once not in order to draw, but to gain time on the clock (when an increment is being used) or to bring themselves closer to the time control (at which point they will receive more time). Occasionally, players miscount and inadvertently repeat the position more than once, thus allowing their opponent to claim a draw in an unfavourable position. Adams versus Ponomariov, Wijk aan Zee 2005 may have been a recent example of this (Friedel 2005).
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
As noted above, one of the players must claim a draw by threefold repetition for the rule to be applied, otherwise the game continues. In the fifth game[6] of the 1921 World Chess Championship match between José Raúl Capablanca and Emanuel Lasker, the same position occurred three times, but no draw was claimed. From the position in the diagram, after 34... h5, the moves were:
The game continued; Lasker blundered and resigned on move 46. Capablanca repeated the position to gain time on the clock (i.e. get in some quick moves before time control) (Kasparov 2003:266–67). (Capablanca went on to win the match and became world champion.)
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
The first game between world champion Emanuel Lasker and future (1927) world champion Alexander Alekhine ended in a short draw, due to a forced repetition of positions: 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Nf6 5. Nc3 Bb4 6. Nxc6 bxc6 7. Bd3 d5 8. exd5 cxd5 9. O-O O-O 10. Bg5 Be6 11. Qf3 Be7 12. Rfe1 h6 13. Bxh6 gxh6 14. Rxe6 fxe6 15. Qg3+ Kh8 16. Qg6 and the players agreed to a draw because Black cannot avoid the repetition of positions: 16... Qe8 17. Qxh6+ Kg8 18. Qg5+ Kh8 19. Qh6+ (Hooper & Whyld 1992) (under Repetition of Position).
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
Interestingly, these two players had another game[7] in 1914 in which Alekhine (this time with the black pieces) again achieved a draw by a similar process (Bott & Morrison 1966:14).
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
A famous draw by threefold repetition occurred in a game[8] between Viktor Korchnoi and Lajos Portisch in 1970 in the Russia (USSR) vs Rest of the World match. Portisch allowed a threefold repetition in a winning position and was criticized by teammate Bobby Fischer for allowing it (Brady 1973:163). If Portisch had won the game, the match would have been a tie. Play continued:
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
In the game between Garry Kasparov and Deep Blue, the players agreed to a draw, because if White played 50. g8=Q, Black could get a draw by threefold repetition: 50... Rd1+, 51. K-any, Rd2+ 52. Kb1 Rd1+, etc. (Hsu 2002:251–52).
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
Some chess opening lines have been analyzed out to a draw by threefold repetition, such as this position from a line of the Giuoco Piano. White has nothing better than to force a draw:
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
Another example is this position from a line of the Pirc Defence. Black can get a draw after the moves 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 c5 6.Bb5+ Bd7 7. e5 Ng4 8. e6 fxe6 9.Ng5 (diagram) Bxb5! 10.Nxe6 Bxd4!! 11.Nxd8 Bf2+ and White cannot escape the checks.
Even top players have made incorrect claims of a draw under this rule. The Karpov versus Miles game is an example of the right to castle must be the same in all positions. The Fischer versus Spassky game is an example that it must be the same player's move in all three positions.
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
The clause about the right to capture en passant and the right to castle is a subtle but important one. In a game between grandmasters Anatoly Karpov and Anthony Miles (Tilburg 1986), Karpov had less than five minutes remaining on his clock, in which to finish a specified number of moves or forfeit the game. He claimed a draw by repetition after checking his scoresheet carefully, whereupon it was pointed out to him that in the first occurrence of position, Black's king had had the right to castle, whereas in the second and third it had not. Tournament rules stipulated that a player be penalized with three minutes of their time for incorrect claims, which left Karpov's flag on the verge of falling. By then, Miles had had his fun, and took the draw. (Miles should have readily accepted a draw in that position, but Karpov was close to losing the game because of time control). See the diagram for the position after 22. Nb5. The game continued 22. ... Ra4 23. Nc3 Ra8 24. Nb5 Ra4 25. Nc3 Ra8 26. Nb5. Black could castle queenside the first time the position in the diagram occurred, but not when the position was repeated.[9]
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
In the twentieth game of the Bobby Fischer versus Boris Spassky World Chess Championship 1972, Fischer called the arbiter Lothar Schmid to claim a draw because of threefold repetition. Spassky did not dispute it and signed the scoresheets before the arbiter ruled (Gligorić 1972:119). After the draw had been agreed, it was pointed out that the position had occurred after White's forty-eighth and fiftieth moves, and again after Black's fifty-fourth move (the final position). So the claim was actually invalid because it was not the same player's turn to move in all three instances, but the draw result stood (Alexander 1972:137–38).[10]
| a | b | c | d | e | f | g | h | ||
| 8 | 8 | ||||||||
| 7 | 7 | ||||||||
| 6 | 6 | ||||||||
| 5 | 5 | ||||||||
| 4 | 4 | ||||||||
| 3 | 3 | ||||||||
| 2 | 2 | ||||||||
| 1 | 1 | ||||||||
| a | b | c | d | e | f | g | h |
At various times in the history of chess, the rule has been variously formulated. In Tim Harding's MegaCorr database (a collection of correspondence chess games), the notes to a game between the cities of Pest and Paris played between 1842 and 1845 state that a sixfold repetition was necessary to claim a draw. The game went: 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Bd6 7.O-O O-O 8.c4 Be6 9.Qc2 f5 10.Qb3 dxc4 11.Qxb7 c6 12.Bxe4 fxe4 13.Ng5 Bf5 14.Nc3 Qd7 15.Qxd7 Nxd7 16.Ngxe4 Bc7 17.Re1 Rab8 18.Re2 Nb6 19.Nc5 Bd6 20.N5e4 Bc7 21.Nc5 Bd6 22.N5e4 Bc7 23.Nc5 Bd6 24.N5e4 Bc7 25.Nc5 Bd6 26.N5e4 Bc7 27.Nc5 and now instead of taking the sixfold repetition draw with 27...Bd6 28.N5e4 Bc7, Paris diverged with 27...Bd3 and went on to lose the game.
The first use of such a rule was in a tournament was in London in 1883, but was stated vaguely:
... if a series of moves be repeated three times the opponent can claim a draw.
The rule was stated more precisely after the tournament and was based on positions instead of moves. The rules for the first official World Chess Championship 1886 match between Wilhelm Steinitz and Johannes Zukertort stated:
... if both players repeat the same series of moves six times in succession, then either player may claim a draw.
In two of the games the same position was repeated three times. The rule was modified soon afterward to be based on positions instead of moves and for three repetitions (McCrary 2004).
|
|
|||||