In November 2006, reigning world chess champion Vladimir Kramnik competed in the World Chess Challenge: Man vs. After 55.Bd5 Kh7 56.Kf7 Kh8 the players agreed to a draw.Ĭhandler had numerous moves that would have maintained his winning position, the fastest being 54.h4 and 54.Bf5 according to the Shredder tablebase. Black controls the h8 square and cannot be chased or squeezed away from it, and so White cannot promote his pawn. gxh6+?, but instead of the expected 54.Kxh6, Polgar played 54.Kh8, leading to almost the same king, bishop, and rook pawn versus bare king situation as Chandler had calculated that he would avoid, and the small difference that White has two rook pawns rather than one has no effect on the result. But Chandler calculates further, and realizes that it is he who will win control over the h8 square after 55.Kf6, and thereby win the game. However, since the bishop is unable to control the promotion square h8, Black will draw if she is able to get her king to control h8 due to the wrong rook pawn fortress. Chandler realized that after 54.gxh6+ Kxh6 he will be left with the considerable material advantage of a rook pawn and bishop against a bare king. His opponent, Susan Polgar, played the wily trap 53.Ng8–h6 !?. In the diagram position, Chandler is completely winning. In this example, from a tournament in Biel in 1987, the game did not result in a loss for the blunderer, but led to an embarrassing draw for the British GM Murray Chandler. The US Chess Federation also implemented this rule, effective as of Janu(a change to rule 15A), although it is not universally enforced. However, in 2005 the International Chess Federation ( FIDE) banned it, instead requiring that the move be made before being written down. This practice was not uncommon even at the grandmaster level. One technique formerly recommended to avoid blunders was to write down the planned move on the score sheet, then take one last look before making it. Neglecting these possibilities leaves a player vulnerable to simple tactical errors. In particular, checks, captures, and threats need to be considered at each move. In chess annotation, blunders are typically marked with a double question mark, " ?", after the move.Įspecially among amateur and novice players, blunders often occur because of a faulty thought process where they do not consider the opponent's forcing moves. A weak move from a novice player might be explained by the player's lack of skill, while the same move from a master might be called a blunder.
What qualifies as a "blunder" rather than a normal mistake is somewhat subjective. While the opponent making a blunder may seem like a stroke of luck, giving the opponent opportunities to blunder is an important skill in over the board chess. Although blunders are more common in amateur games, all human players make them, even at the world championship level. It is usually caused by some tactical oversight, whether it be from time trouble, overconfidence or carelessness. In chess, a blunder is a critically bad move.