Compensation (delay methods)These methods require the use a special clock, called a delay clock. There are two main forms which provide compensation for both the time lost in physically making a move and to make it such that a player can avoid having an ever-decreasing amount of time remaining.
- Bronstein delay, invented by David Bronstein. When it becomes a player's turn to move, the clock waits for the delay period before starting to subtract from the player's remaining time. For example, if the delay is five seconds, the clock waits for five seconds before counting down. The time is not accumulated. If the player moves within the delay period, no time is subtracted from his remaining time.
- Fischer delay, invented by Bobby Fischer. When it becomes a player's turn to move, the delay is added to the player's remaining time. For example, if the delay is five seconds and the player has ten minutes remaining on his clock, when his clock is activated, he now has ten minutes and five seconds remaining. Time can be accumulated, so if the player moves within the delay period, his remaining time actually increases. This style of time control is common on internet chess servers, where the delay is termed an "increment".
Penalty formatsSuch methods exact a points penalty, or fine, on the player who breaches their time limit. One example occurs in Go, where the Ing Rules enforce fines on breaches of main time and overtime periods. In tournament Scrabble the time control is standardized to 25 minutes per side with a 10-point penalty for each minute or part thereof that is used in excess, so that overstepping the allotted time by 61 seconds carries a 20-point penalty.
Time troubleFrequently, players use up a large portion of their time early in the game, and are left with only a few minutes for the final moves. A player with little time is said to be in time trouble, and is forced to play quickly, increasing the probability of making blunders.
Rules governing time trouble in ChessFIDE has some additional rules regarding players in time trouble.
The first rule regards the recording of moves. A player with less than five minutes remaining, in a game where there is not a 30-second or greater time increment per move, is not required to keep score as usual. However if the player makes the time control, he must update the scoresheet before making a move as soon as the flag falls, marking expiry of the first, and now passed, time control. If only one player is in time trouble and not recording moves, the opponent's scoresheet may be used to update the score. In the case of mutual time pressure, where both players have stopped recording the moves, the tournament director or an assistant should be on hand to record the moves as they are played, and their notes can be used to update the scoresheets upon passage of the time control. If the game score is not recorded by anybody during the time pressure period, the players, shall endeavor to reconstruct the moves of the game, under the control of the tournament director, if this is not possible the game continues with the next move being regarded as the first move of the next time control.
The second rule regards the arbiter's possibility of ending a game as drawn due to a player's lack of effort in winning the game by "normal means". Occasionally it happens in a sudden death time control without increments that a player has trouble in physically executing an indefinite series of moves in the time remaining. The opponent could try playing on this, and continue to play on in the hopes of winning by time forfeit, rather than by winning the position on the board. To prevent this FIDE has article 10.2 A player with less than two minutes remaining can, if he considers that the opponent is no longer trying to win the game by normal means, claim a draw and summon the arbiter. The arbiter may accept the claim (which ends the game immediately as a draw), reject the claim (after which the game continues, with the opponent receiving two additional minutes), or postpone the decision. In this case the opponent may be given two minutes extra, and the game continues until the arbiter makes a call or the claimant's flag falls after which the arbiter makes a decision. Decisions made by the arbiter under 10.2 are final.
USCF versionTournaments governed under the rules of the United States Chess Federation have a similar rule to FIDE's 10.2, called the "insufficient losing chances" rule. A player with less than two minutes remaining without time delay can petition the tournament director for a draw on the grounds that the opponent has no reasonable chance of winning the position, had both players had ample time. In USCF's guidelines, this would mean an average tournament player (class C) having a less than a 10% probability of losing the position against a master, with both players having sufficient time. The tournament director may accept the claim (ending the game as drawn), reject the claim and penalize the claimant with one minute less time, or postpone the decision. If the tournament director postpones the decision, there is the option of substituting a non-delay clock with a delay clock with the claimant having his remaining time halved. Since the insufficient losing chances rules calls upon discretion from the tournament director, clocks with the time delay feature are preferred over clocks without them.
Notes and references
- Game time controls on BrainKing
- A sudden death time control determines the 2008 [[U.S. Women's Chess Championship] ]