The chess clock

In chess clubs and chess tournaments every game is played with a chess clock. The control of thinking time is a necessary component of a tournament game.  It prevents one player from unfairly prolonging the length of a game and is an important element in competitive chess. The player who has the foresight to divide up his playing time, will later at critical moments have an advantage over an opponent who already finds himself in time trouble (Zeitnot).
Whenever a player has the move his clock is running. As soon as he has played his move he uses the hand which has moved the piece on the board to press a button on his side of the clock. This button stops his own clock and starts his opponent’s.
Whoever oversteps the time control set for the game loses. There is an exception for positions which cannot be won even with the weakest possible play by the opponent.. The clock shows when the time limit has been exceeded for the mode of play for which it has been set. According to the rules of chess the opponent must notice this and claim the win. If it is not noticed that the opponent has overstepped the time limit the game simply continues. In blitz chess it can happen that both players overstep the limit. Then the game is drawn.
Nowadays in tournament and club chess three types of time control are usual:

  1. Tournament thinking time: usually a player must make 40 moves within a fixed time, normally two hours. For the remainder of the game a fixed total time is set, e.g. 30 minutes per player. In this mode a game cannot last longer than five hours. There remains enough time to be able to carry out deep calculation of variations in difficult positions.
  2. Blitz or rapid games: a fixed time is agreed for the whole game. A specially popular one is five minute blitz. Each player has five minutes for the whole game. The clock shows a countdown of the time remaining.
  3. Blitz game with Fischer clock: the clock invented by world champion Bobby Fischer is able to credit to a player extra thinking time (an increment) for each move he has made, e.g. two seconds. This only works with modern digital clocks. It makes for a calmer form of blitz chess in which in the final phase the decision is not reached on purely physical ability to press the clock more quickly. Yet it is this dexterity in making rapid and accurate moves which constitutes the attracrion of blitz chess (“the clock is a piece”).  

The chess clock provldes an elegant way to deal with players who are late in tournaments. At the pre-determined starting time for a round all the clocks are simply started. That way anyone who is late loses some of his thinking time, If a player does not appear within an hour the he loses the game to a walkover.
The first tournament played with chess clocks took place in 1883 in London.

Digitale Schachuhr von DGT Projects

Heuer Schachuhr (1970) | Photo: Stephen Kong
Sutton Coldfieds Chess Timer (1938) | Photo: Stephen Kong
Tanner Schachuhr (1900) | Photo: Stephen Kong