Time controls

A time control is a mechanism in the tournament play of almost all two-player board games so that each round of the match can finish in a timely way and the tournament can proceed. Time controls are typically enforced by means of a game clock. Time pressure (or time trouble or zeitnot) is the situation of having very little time on a player's clock to complete their remaining moves.

In the case of chess, the World Chess Federation FIDE sets a single classical time control for all major FIDE events, according to the handbook: 90 minutes for the first 40 moves, followed by 30 minutes for the rest of the game, with an addition of 30 seconds per move (cf. Fischer delay below) starting from move one. Exceptions can be made, though; for example, the Candidates tournaments for the World Championship have been played at 120 minutes for 40 moves, followed by 60 minutes for 20 moves, followed by 15 minutes for the rest of the game, with a 30-second increment starting on move 61. Also, FIDE formulate different time controls for fast chess.

The amount of time given to each player to complete their moves will vary from game to game. However most games tend to change the classification of tournaments according to the length of time given to the players. Shorter time limits, which do not afford due consideration to moves, are afforded a lesser degree of importance. Indeed, shorter limits are normally given special names to distinguish them.

In chess, the categories of time limits are: 'lightning', 'bullet', 'blitz', and 'rapid'. 'Lightning' games are the fastest, with either a very short time limit per move (such as ten seconds) or a very short total time (such as one minute). 'Bullet' games typically give two or three minutes per player. 'Blitz' games typically give five to ten minutes per player, and 'rapid' games give between ten and sixty minutes. By way of contrast, for Go anything under twenty minutes could be considered blitz.

The exact approach to using a game clock to regulate games varies considerably.

This is the simplest methodology. Each player is assigned a fixed amount of time for the whole game: once a player's main time expires, he loses the game.

Each player's clock starts with a specified time (e.g. 1 minute, 10 min etc.). While Player 1 is deciding a move, player 1's clock time is decreasing and Player 2's clock time is increasing. This is similar to how an hourglass works; sand empties from one container and fills into the other. Moving slowly gives your opponent extra time. The sum of both clocks will always remain the same. There is no maximum amount of time allotted for a game with this timing method; as long as both players play quickly, the game will continue until its natural end. When time runs out on one player's clock the game is over and that player loses. Use of this time control is uncommon.

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