Chess clock

How to use the chess clock

Pick a time control and open the clock. Each player gets half of the screen, and the top half is turned around so it faces the player across the table. Whoever plays Black taps first to start White’s clock. After that, make your move and tap your side to start your opponent’s time. The running clock glows green and turns red when time is short. When a clock hits zero, it flags and the game is over.

Increment, delay and Bronstein

• Increment (also called Fischer): you get extra seconds added after every move. “3+2” means 3 minutes each plus 2 seconds per move.
• Delay (simple or US delay): each turn, your clock waits a few seconds before it starts counting down. Move within the delay and you lose no time at all.
• Bronstein delay: after your move you get back the time you used, up to the delay. Unlike increment, you can never end up with more time than you had.

Handy extras

Pause the clocks at any time, for example to call an arbiter or settle a question. The move counters show how many moves each player has made. While the clock runs it keeps your screen awake, and the full-screen button hides everything else. On a computer, press the space bar to tap the running clock and P to pause.

No board handy? Play on the two-player board instead. It has the same clock built in.