Cheating in Chess - Touch-move Rule

Touch-move Rule

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 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 and allow Polgár the win. 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 ¼ second. Cognitive psychologist Robert Solso stated that that is too short a time to make a conscious decision.

A 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 move was allowed to stand. This incident earned Matulović the nickname "J'adoubovic".