Bronstein delay

With Bronstein delay, the clock counts down immediately during the turn. After the player completes the move and presses the clock, it restores the smaller of two amounts: the preset delay or the time just used. With a five-second delay, a move made in three seconds restores those three seconds and costs no net main time; a move made in eight seconds restores five and costs three. Some clocks instead show a separate delay countdown before the main time starts; the FIDE Arbiters' Manual calls that simple or US delay. Both methods have the same overall effect, but their clock operation differs.

Unused delay does not carry over to later moves. That is the key practical difference from increment, where time is added to the clock and can increase the remaining balance. Bronstein delay is a specific form of delay and must be stated as part of the event's time control. Its practical effect is to give a small protected window for each move without turning it into a growing reserve.