chess clock

A chess clock is a device used to regulate the time each player has to make their moves in a game of chess. The first time controls were introduced in 1861, initially using sandglasses, which were later replaced by mechanical clocks in 1883. These clocks feature two timers, each with a button that a player presses after completing a move, stopping their time and starting their opponent's.

Modern chess clocks often include a "flag" to clearly indicate when a player's time has expired. In the 1990s, the "Fischer clock" was patented, adding a small increment of time to a player's clock after each move, which helps prevent games from being decided solely by time pressure and reduces the need for adjournments. This innovation has made chess more spectator-friendly, particularly for television audiences.123