The Chess Clock – It’s Getting Complicated Out There

My favorite type chess clock.

A chess (or game) clock consists of two adjacent clock and buttons to stop one clock while starting the other, such that the two component clocks never run simultaneously.

Game clocks are used in two-player games where the players move in turn. The purpose is to keep track of the total time each player takes for his or her own moves, and ensure that neither player overly delays the game.

Nearly every competitive board game has adopted the “chess” clock.

The first time that game clocks were used in a chess tournament was in the London Chess Tournament – 1883!

The simplest time control is "sudden death", in which players must make a predetermined number of moves in a certain amount of time or forfeit immediately.

The players may take more or less time over any individual move. The opening moves in chess are often played quickly due to their familiarity, which leaves the players more time to consider more complex and unfamiliar positions later.

Analog clocks are equipped with a "flag" (a Dutch invention) that falls to indicate the exact moment the player's time has expired. Analog clocks use mechanical buttons. Pressing the button on one player's side physically stops the movement of that player's clock and releases the hold on the opponent's.

The drawbacks of the mechanical clocks include accuracy and matching of the two clocks, and matching of the indicators (flags) of time expiration. Additional time cannot easily be added for more complex time controls, especially those that call for an increment or delay on every move. However, a malfunctioning analog clock is a less serious event than a malfunctioning digital clock.

In 1973, to address the issues with analog clocks, Bruce Cheney, a Cornell University Electrical Engineering student and chess player, created the first digital chess clock as a project for an undergraduate EE course. Typical of most inventions, it was crude compared to the products on the market 30 years later and was limited by the technology that existed at the time. The clock only had one mode: time ran forward. It could be reset, but not set. It did not count the number of moves. But it successfully addressed the original goals of the project (accurate and matched timing).

Digital clocks and Internet gaming have spurred a wave of experimentation with more varied and complex time controls than the traditional standard.  One particularly notable development, which has gained quite wide acceptance in chess, was proposed by former world champion Bobby Fischer, who in 1988 filed for a US patent (awarded in 1989) for a new type of digital chess clock.

Fischer's digital clock gave each player a fixed period of time at the start of the game and then added a small amount after each move. In this way, the players would never be desperately short of time, but games could also be completed more quickly, doing away with the need for adjournments (in which a game is left incomplete to be finished at a later date).

Although it was slow to catch on, a large number of top class tournaments use Fischer's system, though usually in combination with the more traditional clocks (at lower levels, more traditional clocks are still employed, as they are cheaper). 

There are six main types of time controls: (1) Fischer (invented by Bobby Fischer), (2) Bronstein (invented by David Bronstein), (3) Simple Delay, (4) Game Word and (5) Hour Glass, (6) Simple count down with a fixed amount of time.

The first three time controls implement some sort of delay clock, a small amount of time that is added for each move. The reason is that with a sudden-death time limit, all moves must be completed in the specified time, or the player loses. With a small delay added at each move, the player always has at least that much time to make a move. The two types of delay clocks differ in how the delay is implemented. The last two time controls are somewhat different, as they do not rely on time delay, as explained below.

1) Fischer—before a player has made his move, a specified time increment is added to his clock. Time can be accumulated, so if the player moves within the delay period, his remaining time actually increases. For example, if the delay time is five seconds, and a player has four seconds left on his clock, as soon as his opponent moves, he receives the increment and has nine seconds to make a move. If he takes two seconds to move, on the start of his next move he has twelve seconds. There is also a variant of this time control that adds the delay after a player makes his move (Fischer after), so the delay is added to the player's remaining time and is available for his next move. If however time runs out during his move, the game ends without the delay time being added. This variant prevents the player who is in time-trouble to take advantage of the extra-time.

2) Bronstein delay—with the Bronstein timing method, the increment is always added after the move. But unlike Fischer, not always the maximum increment is added. If a player expends more than the specified increment, then the entire increment is added to the player's clock. But if a player has moved faster than the time increment, only the exact amount of time expended by the player is added. For example, if the delay is five seconds, the player has ten seconds left in his clock before his turn and during his turn he spends three seconds, after he presses the clock button to indicate the end of his turn, his clock increases by only three seconds (not five).

3) Simple delay—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. This time control is similar to a Bronstein with time added before the move.

4) Word—it is a sudden death time control, without any increment or delay. The difference here is that when the time expires by dropping to zero, a flag is set, and the clock immediately starts counting up without limit. This time control applies to games where the amount of time used after the allowed time can be subtracted from the player's score as a penalty, such as Tournament or Club Scrabble.

5) Hour Glass—a player loses in this time control when he allows the difference between both clocks to reach the specified total amount. For example, if the total is defined as one minute, both players start their clocks at thirty seconds. Every second the first player uses to think in his moves is subtracted from his clock and added to his opponent's clock. If he uses thirty seconds to move, the difference between the clocks reaches one minute, and the time flag falls to indicate that he loses by time. If he has used twenty nine seconds and then pushes the clock's button, he has one second left on his clock and his opponent has fifty-nine seconds.

6) Count Down – run out of time and you lose. Still my favorite!

As a charter member of the KISS (keep it simple stupid) Club, I still think all that was ever needed - with the invention of the more accurate digital clocks - was slight buzzer and/or light to activate when time ran out, instead of the flag! Right now if feels like you need a college degree in Digital Clock Setting in order to play chess.

But the digital clock is not going away – the analog clock (see picture) is.