Delay (US delay) - chess term

Delay

Definition

In modern chess timing, delay (often called “U.S. delay” or “Bronstein delay”) is a clock feature that postpones the countdown of a player’s main thinking time for a fixed number of seconds at the start of every move. If the player completes the move before the delay period ends, no main time is consumed; if the move takes longer, the clock begins subtracting from the player’s remaining time once the delay expires.

How It Is Used

Notation in event announcements – A control such as “G/90; d/10” means each player has 90 minutes for the entire game with a 10-second delay on every move.
Clock display – On most digital clocks the delay ticks down first (often flashing), then the main time starts. If the player presses the lever before the delay reaches 0, the displayed main time remains unchanged.
Practical play – In sharp time trouble, a player can “live off the delay,” making each move within the delay interval to stay on 0:00 without flagging.

Strategic and Psychological Significance

Delay changes late-game strategy compared with classical sudden-death controls:

Endgame technique – Players in severe time trouble can still calculate a few seconds per move, reducing blunder frequency and rewarding superior endgame skill.
Flag tactics – Unlike pure sudden death, it is harder to “flag” an opponent who can move instantly each turn; attacking players must win by force, not by milking the clock.
Opening preparation – Knowing that a short cushion exists, players may spend their main time more liberally early on, trusting the delay to rescue them in the scramble.

Historical Context

The concept originated with GM David Bronstein, who proposed a fairer timing method after witnessing painful time-pressure collapses in the mid-20th century. While FIDE adopted the related increment (often called the “Fischer increment”) for elite events, the United States Chess Federation (USCF) favored Bronstein’s delay beginning in the 1990s, and delay settings remain standard in U.S. open tournaments today.

Comparison: Delay vs. Increment

Delay – The main time pauses for n seconds; unused delay does not accumulate.
Increment – After each move n seconds are added to the main time, allowing a player to build up a large reserve with fast play.

Although both mechanisms prevent “zero-second” finishes, increment generally gives slightly more thinking time across a long series of quick moves. Delay is therefore viewed as the more conservative option, preserving the traditional importance of overall clock management.

Illustrative Example

Imagine a rapid game set to “G/25; d/5.” White’s clock shows 0:02 (two seconds) with a 5-second delay:

Black completes 35...Qh4+, presses the clock.
White’s delay begins at 0:05. White instantly plays 36. Kg1.
Because the move took under five seconds, White’s main time remains at 2 seconds.
The cycle repeats; White can theoretically survive indefinitely if every move is made within five seconds.

Famous Episodes

Hikaru Nakamura, Foxwoods Open 2005 – In a must-win last round to tie for first, Nakamura reached an equal rook endgame with only seconds left. Using the 10-second delay masterfully, he outplayed his opponent and secured the full point, a practical example of “living off the delay.”
U.S. Championship 2009 – Because of the 30-second increment (not delay), Kamsky avoided flagging in a lost position against Onischuk. The incident prompted discussion among organizers about switching from increment to delay to keep games from dragging on in hopeless situations.

Interesting Facts & Anecdotes

The popular DGT 3000 clock allows both increment and delay; however, in “delay” mode it displays only the remaining main time, so spectators often think a player has hit zero when in fact the delay is still running.
Some blitz servers emulate delay by showing a colored bar that must empty before time begins to tick; however, most online platforms prefer increment for simplicity.
USCF official wording for a standard scholastic control is “G/30; d/5, delay clock preferred; if no delay clock is available, each player receives an additional five minutes.” Thus delay has even altered rules for equipment preference!