Chess clock Chess clock A chess clock consists of two adjacent clocks with buttons to stop one clock while starting the other, so that the two clocks never run simultaneously. Chess clocks are used in chess and other two-player games where the players move in turn. The purpose is to keep track of the total time each player takes for their own moves, and ensure that neither player overly delays the game. Chess clocks were first used extensively in tournament chess, and are often called game clocks. The first time that game clocks were used in a chess tournament was in the
White and Black in chess with an extra tempo. As late as the mid-to-late 19th century, the practice of White moving first had not yet become standard. George Walker in his popular treatise "The Art of Chess-Play: A New Treatise on the Game of Chess" (4th edition 1846), set forth the rules of London's St. George's Chess Club promulgated in June, 1841. "Law III" provided that the player who moved first had the choice of color; if the players played more games at the same sitting, the first move would alternate, but each player would continue to use the same colored pieces as he had