Definitions

# Threefold repetition

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 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 capture en passant and to castle. Positions are considered the same if the same type of piece is on a given square. So, for instance, if a player has two rooks and the rooks are on the same squares, it does not matter if the positions of the two rooks have been exchanged. The game is not automatically drawn if this happens — one of the players, on their turn to move, must claim the draw with the arbiter.

## The rule

The relevant rule in the FIDE laws of chess is 9.2, which reads:

The game is drawn, upon a correct claim by the player having the move, when the same position, for at least the third time (not necessarily by sequential repetition of moves)

a. is about to appear, if he first writes his move on his scoresheet and declares to the arbiter his intention to make this move, or

b. has just appeared, and the player claiming the draw has the move.

Positions as in (a) and (b) are considered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same.
Positions are not [considered to be] the same if a pawn that could have been captured en passant can no longer be captured or if the right to castle has been changed.

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 don't matter – they can be the same or different. The rule applies to positions, not moves.

## Examples

The seventeenth , eighteenth , and twentieth games of the 1972 World Championshop match between Bobby Fischer and Boris Spassky were declared draws because of threefold repetition, although the twentieth game was an incorrect claim (see below).

### Fischer versus Petrosian, 1971

In the third game 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:
30... Qe5
31. Qh5 Qf6
32. Qe2 (second time) Re5
33. Qd3 Rd5?
and then Fischer wrote his next move
34. Qe2 (third time)
on his scoresheet, which is the third appearance of the position with Black to move, and he claimed a draw. At first Petrosian was not aware of what was going on. Incidentally, this was the first time a draw by three-fold repetition had been claimed in his career , , .

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-Ponomariov, Wijk aan Zee 2005 may have been a recent example of this .

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 of the 1921 World Chess Championship match between Jose 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:

35. Qd8+ Kg7
36. Qg5+ Kf8 (second time)
37. Qd8+ Kg7
38. Qg5+ Kf8 (third time)

The game continued and Lasker resigned on move 46. (Capablanca went on to win the match and became world champion.)

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+ (under Repetition of Position).

Interestingly, these two players had another game in 1914 in which Alekhine (this time with the black pieces) again achieved a draw by a similar process .

### Korchnoi versus Portisch, 1970

A famous draw by three-fold repetition occurred in a game between Viktor Korchnoi and Lajos Portisch in 1970 in the Russia (USSR) vs Rest of the World match. Portisch allowed a three-fold repetition in a winning position and was criticized by teammate Bobby Fischer for allowing it . If Portisch had won the game, the match would have been a tie. Play continued:

64... Rh6+
65. Kg4 Rd6
66. Kh5 Kf6
67. Rb2 Kg7
68. Rb8 ½-½

### Kasparov versus Deep Blue, 1997

In the game Deep Blue versus Garry Kasparov#1997 Game 5, Kasparov vs. Deep Blue 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 three-fold repetition: 50... Rd1+, 51. K-any, Rd2+ 52. Kb1 Rd1+, etc .

### In the opening

Some chess opening lines have been analyzed out to a draw by three-fold repetition, such as this position from a line of the Giuoco Piano. White has nothing better than to force a draw:
21. Bg6+ Kf8
22. Bh7 etc
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.

## Incorrect claims

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. 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. In the twentieth game of the Bobby Fischer versus Boris Spassky World Chess Championship 1972, Fischer claimed a draw because of threefold repetition. Spassky did not dispute it and the arbiter Lothar Schmid agreed. 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 .

## History

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 .