--- title: "Chess clock" url: "https://georgelichess.com/glossary/chess-clock.md" canonical_url: "https://georgelichess.com/glossary/chess-clock" last_updated: "2026-11-07" type: "reference" summary: "A chess clock is a pair of linked timers of which only one runs at a time. The clock turns chess into a race as well as a puzzle." related: ["https://georgelichess.com/glossary/flagging.md", "https://georgelichess.com/glossary/increment.md", "https://georgelichess.com/glossary/delay.md", "https://georgelichess.com/glossary/time-control.md", "https://georgelichess.com/glossary/arbiter.md", "https://georgelichess.com/glossary/illegal-move.md", "https://georgelichess.com/glossary/category/rules-notation.md", "https://georgelichess.com/glossary.md"] --- # Chess clock > **For AI agents:** the complete index of GeorgeLiChess pages is [llms.txt](https://georgelichess.com/llms.txt). Every page is also served as markdown at its URL plus .md. A chess clock is a pair of linked timers of which only one runs at a time. The clock turns chess into a race as well as a puzzle. A chess clock is a pair of linked timers of which only one runs at a time; after each move a player presses their side to stop their own time and start the opponent's. The clock turns chess into a race as well as a puzzle. Each player has a time display with a flag. When you make your move, you press your side, which stops your time and starts your opponent's, and that press completes the move. The time between moving on the board and pressing counts against you. Press with the same hand that made the move, and do not hover over the clock or press it hard. [Time controls](https://georgelichess.com/glossary/time-control.md) are specified in advance. Some add a fixed bonus after each move, called an [increment](https://georgelichess.com/glossary/increment.md), and others give a delay at the start of each turn before the main time begins to count down. The Laws describe the delay mode precisely: a fixed extra time at each turn, and the main time only runs once that extra time has expired. Everything on a clock is treated as correct unless it is evidently faulty. The [arbiter](https://georgelichess.com/glossary/arbiter.md) decides where the clock is placed, White's clock is started at the scheduled start time, and you may pause the clock only to call the arbiter. Practice clock handling in training games, because careless presses become [illegal moves](https://georgelichess.com/glossary/illegal-move.md) or penalties. It sits close to [Correspondence chess](https://georgelichess.com/glossary/correspondence-chess.md). Correspondence chess is played over a long period, with moves sent by post, email or a website, so each player has days to think about every move. Also worth reading is [Simultaneous exhibition](https://georgelichess.com/glossary/simultaneous-exhibition.md). A simultaneous exhibition is an event in which one strong player plays many opponents at once, moving from board to board while each opponent has time to think between visits. Also worth reading is [Flagging](https://georgelichess.com/glossary/flagging.md). Flagging is winning, or claiming to win, on time because an opponent's clock has run out; the flag-fall loses the game unless the other side could never checkmate. Knowing "Chess clock" is the easy part; what to practice next depends on your rating, and the [improvement plans by rating band](https://georgelichess.com/improve.md) list the habits worth building at each level. ## Related terms - [Flagging](https://georgelichess.com/glossary/flagging.md) - [Increment](https://georgelichess.com/glossary/increment.md) - [Delay](https://georgelichess.com/glossary/delay.md) - [Time control](https://georgelichess.com/glossary/time-control.md) - [Arbiter](https://georgelichess.com/glossary/arbiter.md) - [Illegal move](https://georgelichess.com/glossary/illegal-move.md) ## Guides that go further - [How to choose a chess coach](https://georgelichess.com/how-to-choose-a-chess-coach.md): What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid. - [How much does chess coaching cost?](https://georgelichess.com/chess-coaching-cost.md): Published rates for private, group and subscription chess coaching, with the source and the date of each. - [The first lesson](https://georgelichess.com/book/first-lesson.md): A game review, a read on your level and a written study plan from George Li. ## Sources - FIDE Laws of Chess (effective 1 January 2023) (Articles 6.1 and 6.2), read 2026-10-21: https://handbook.fide.com/chapter/E012023 - FIDE Laws of Chess (effective 1 January 2023) (Articles 6.3 and 6.5 to 6.6), read 2026-10-21: https://handbook.fide.com/chapter/E012023 - FIDE Laws of Chess (effective 1 January 2023) (Articles 6.10 and 6.11), read 2026-10-21: https://handbook.fide.com/chapter/E012023 [Book your first lesson](https://georgelichess.com/book.md) and George Li reviews your games and builds a study plan around them. Questions about lessons: write to hello@georgelichess.com. ## Related - [Flagging in chess](https://georgelichess.com/glossary/flagging.md) - [Increment in chess](https://georgelichess.com/glossary/increment.md) - [Delay in chess](https://georgelichess.com/glossary/delay.md) - [Time control in chess](https://georgelichess.com/glossary/time-control.md) - [Arbiter in chess](https://georgelichess.com/glossary/arbiter.md) - [Illegal move in chess](https://georgelichess.com/glossary/illegal-move.md) - [Chess terms: Rules, notation and equipment](https://georgelichess.com/glossary/category/rules-notation.md) - [Chess terms glossary: plain definitions](https://georgelichess.com/glossary.md)