Cheating in chess refers to a deliberate violation of the rules of chess or other unethical behaviour that is intended to give an unfair advantage to a player or team. Cheating can occur in many forms and can take place before, during, or possibly even after a game. Commonly cited instances of cheating include: collusion with spectators or other players, linking to remote computers, rating manipulation, misuse of the touch-move rule, and the pre-arranged draw. Many suspiciously-motivated practices are not comprehensively covered by the rules of chess and so, on ethical or 'moral conduct' grounds only, may be judged by some as acceptable, and by others as cheating.
Even if an arguably unethical action is not covered explicitly by the rules, article 12.1 of the FIDE laws of chess states: "The players shall take no action that will bring the game of chess into disrepute." For example, while deliberately sneaking a captured piece back onto the board may be construed as an illegal move that is sanctioned by a time bonus to the opponent and a reinstatement of the last legal position, the rule forbidding actions that bring chess into disrepute may also be invoked to hand down a more severe sanction such as the loss of the game.
Cheating at chess is almost as old as the game itself, and may even have caused chess-related deaths. According to one legend, a dispute over cheating at chess led King Canute to murder a Danish nobleman. One of the most anthologized chess stories is Slippery Elm (1929) by Percival Wilde, involving a ruse to allow a weak player to beat the club champion, using messages passed on "Slippery Elm" brand throat lozenges. Television shows have engaged the plot of cheating in chess, including a Mission: Impossible episode and a Cheers episode.
In contrast to the modern methods of cheating by playing moves calculated by machines, in the 18th and 19th centuries, the public were hoaxed by the opposite deception in which machines played moves of hidden humans. The first and most famous of the chess automaton hoaxes was The Turk (1770), followed by Ajeeb (1868), and Mephisto (1886).
Over the years, there have been many accusations of collusion, either of players deliberately losing (often to help a friend or teammate get a title norm), or of players agreeing to draws to help both players in a tournament. One of the earliest evidences is with the Fifth American Chess Congress in 1880, when Preston Ware accused James Grundy of reneging on a deal to draw the game, with Grundy instead trying to play for a win. A contemporary newspaper article noted "Ware’s avowal of his right to sell a game in a tourney was a novelty in chess ethics ... Ware’s veracity has not been questioned, only his obliquity of moral vision ..." In later defense of Ware's ethics, six prior allegations of similar collusion and bribery were listed from 1876 to 1880 alone.
Researchers at Washington University in St. Louis claim that Soviet chess masters may have colluded in world chess championships held from 1940 to 1964. The study argues that Soviet players agreed to draws between themselves to improve their standings. While it is generally believed that this collusion sometimes happened, opinions differ over how effective it was. For example, if a leading player draws his game, it may allow his rivals to gain ground on him by winning their games. The most infamous alleged instance, the 1962 Candidates' Tournament, is discussed further at the World Chess Championship 1963 article.
In 2011, IM Greg Shahade wrote that "prearrangement of results is extremely commonplace, even at the highest levels of chess. This especially holds true for draws... There is a bit of a code of silence at the top levels of chess." The subject had been partially broached (in the USA context) by Alex Yermolinsky a few years earlier, saying " It's no secret how people act when facing a last round situation when a draw gives no prize ... People will just dump games, period." Concerning an incident involving 2006 US Championship qualification, Shahade blamed the Swiss system itself for creating perverse incentives. Frederic Friedel reported that the PCA had considered running a series of open tournaments in 1990s, but for similar reasons given by John Nunn ultimately declined, saying that deliberately losing games was "very real in the many open tournaments that are staged all over the world."
In chess, the "touch-move" rule states that if a player (whose turn it is to move) touches one of his pieces, it must be moved if it has a legal move. In addition, if a piece is picked up and released on another square, the move must stand if it is a legal move. If an opponent's piece is touched, it must be captured if it is legal to do so. These rules are often difficult to enforce because the only witnesses are the two players themselves. Nevertheless, violations of these rules are considered to be cheating.
In one famous instance, Garry Kasparov changed his move against Judit Polgár in 1994 after momentarily letting go of a piece. Kasparov went on to win the game. The tournament officials had videotape proving that his hand left the piece, but refused to release the video evidence. A factor counting against Polgár was that she waited a whole day before complaining, and such claims must be made during the game. The videotape revealed that Kasparov did let go of the piece for one quarter second. Cognitive psychologist Robert Solso stated that it is too short a time to make a conscious decision.
Another famous incident occurred in a game between Milan Matulović and István Bilek at the Sousse Interzonal in 1967. Matulović played a losing move but then took it back after saying "J'adoube" ("I adjust" - which should be announced before adjusting pieces on their square). His opponent complained to the arbiter but the modified move was allowed to stand. This incident earned Matulović the nickname "J'adoubovic".
The 2003 European Championship saw a "takeback game" between Zurab Azmaiparashvili and Vladimir Malakhov, who eventually finished first and second in the event. To quote the book Smart Chip by Genna Sosonko:
Both grandmasters were fighting for the lead, and the encounter had huge sporting significance. In an ending that was favourable to him, Azmai[parashvili] picked up the bishop, intending to make a move with it instead of first exchanging rooks. Malakhov recalled: "Seeing that the rooks were still on the board, he said something like, "Oh, first the exchange, of course." put his bishop back, took my rook, and the game continued. I don't know what should have been done differently in this situation --- in Azmai's place, some might have resigned immediately, and in my place, some would have demanded that he make a move with his bishop but I didn't want to ruin the logical development of the duel, so I didn't object when Azmai made a different move: the mistake was obviously nothing to do with chess! When we signed the score sheets, Azmai suggested to me that we consider the game a draw. After the game I was left with an unpleasant aftertaste, but that was due mainly to my own play."
Technology has been used by chess cheats in several ways. Perhaps the most common way is to use a chess program while playing chess remotely, e.g. on the Internet. Another type of cheating, with the aim of boosting one's rating on an Internet chess site, is to sign on with a different IP address and user name (a form of sockpuppetry) to play and lose against themselves. Electronic communication with an accomplice during face-to-face competitive chess is another reported type of cheating. Games can be analyzed after the fact to give a probabilistic determination on whether a player received surreptitious help.
The great multiplication of technological cheating incidents in chess makes it wise to concentrate on those which are either at a high level, or are of historical significance.
In the sixth round a player came to me and said he suspected his opponent, W.S. from L., was using illicit aids during the game. He often left the board for protracted periods of time to go to the toilet, even when (especially when) it was his turn to play. He had done this in earlier rounds against other players as well. I watched W.S. and noticed that he played a number of moves very rapidly and then disappeared in the toilet. I followed him and could hear no sound coming from the stall. I looked under the door and saw that his feet were pointing sideways, so that he could not have been using the toilet. So I entered the neighbouring stall, stood on the toilet bowl and looked over the dividing wall. I saw W.S. standing there with a handheld PC which displayed a running chess program. He was using a stylus to operate it. I immediately disqualified the player. When confronted he claimed that he was only checking his emails, so I asked him to show me the computer, which he refused to do. There are witnesses for my investigation in the toilet, and we will ask the chess federation of our state to ban the player from playing in other tournaments.
Since the introduction of Elo ratings in the 1960s, a number of attempts have been made to manipulate the rating system, either to deliberately inflate one's rating or to disguise one's strength by deliberately losing rating points.
Sandbagging involves deliberately losing rated games in order to lower one's rating so that one is eligible to enter the lower rated section of a tournament with substantial prize money. This is most common in the United States, where the prize money for large open tournaments can be over $10,000, even in the lower rated sections. Sandbagging is very difficult to detect and prove, so USCF has included minimum ratings based on previous ratings or money winnings to minimize the effect.
A limited pool of players who rarely or never play against players from outside of that pool can cause distortions in the Elo rating system, especially if one or more of the players is significantly stronger than the others, or if the results are deliberately manipulated.
Claude Bloodgood was accused of manipulating the USCF rating system in this way; at his peak in 1996 his USCF rating was in excess of 2700, the second highest in the country at the time. As a long-term prison inmate he was necessarily restricted in the range of opponents available to him. The USCF suspected that he had deliberately inflated the ratings of his opponents; Bloodgood denied this, attributing his inflated rating to a quirk in the rating system resulting from his regularly playing against a limited pool of much weaker players.
There was widespread reporting of anomalous Burmese (Myanmar) rating movements in the late 1990s, with Milan Novkovic giving an analysis of manipulation in Schach magazine.
The most notable international example of ratings manipulation involves Romanian Alexandru Crisan, who allegedly falsified tournament reports to gain a Grandmaster title and was ranked 33rd in the world on the April 2001 FIDE rating list. A committee overseeing the matter recommended his rating be erased and his Grandmaster title revoked. While the Romanian Chess Federation initially favored action against Crisan, eventually he himself became the RCF president and changed the policy, creating such a situation that FIDE intervened to broker a resolution regarding many problems in the RCF, including Crisan's rating. Crisan then was arrested and imprisoned on fraud charges relating to his management of the company Urex Rovinari and disappeared from chess, thus failing to fulfill the conditions of the resolution and so activating the above recommendations regarding title revocation. FIDE did not fully update its online information until August 2015, when all his titles were removed and his rating adjusted downwards to 2132. When writing about the Crisan case, Ian Rogers alleges that Andrei Makarov (at the time a FIDE vice-president and Russian chess federation president) had arranged an IM title for himself through non-existing tournaments in 1994.
Rumors of rigged tournaments are not unheard of in the chess world. For instance, in 2005, FIDE refused to ratify norms from the Alushta (Ukraine) tournaments, claiming that the games did not meet ethical expectations. A number of players involved protested over the matter. A different Ukrainian tournament in 2005 was found to be completely fake. Usually the strongest players are not involved in these, as they are more for careerist players to gain title norms or small rating gains, but Zurab Azmaiparashvili was alleged to have rigged the results of the Strumica tournament of 1995 to allow him to reach the chess elite. In 2003, Sveshnikov referred to these high-profile Crisan and Azmaiparashvili incidents as "open secrets", at a time when both purported culprits were heavily involved in FIDE politics.
A player with no knowledge of chess can achieve a 50% score in simultaneous chess by replicating the moves made by one of his white opponents in a match against a black opponent, and vice versa; the opponents in effect play each other rather than the giver of the simul. This may be considered cheating in some events such as Basque chess. This can be used against any even number of opponents. Stage magician Derren Brown used the trick against eight out of nine leading British chess players in his television show.