# Chess Time Control Notation

Example: 6SS, 40/120 sd30 d5

"6SS" indicates a 6-round Swiss system tournament.

"40/120" indicates that each side will have 120 minutes to make the first 40 moves of the game.

"sd30" indicates that after the first 40-move time control is met, each side will have an additional 30 minutes for the remainder of the game ("sd" = sudden death).  Sometimes written as "All/30", especially if it's the only time period.  e.g. "6SS, All/120 d5"

"d5" indicates that there will be a 5-second delay on each move.  SCA uses simple delay.

There are several kinds of delay:

Simple delay (also known as countdown delay and US delay)—With this timing method, the clock waits for the delay period each move before starting to subtract the player's base time. For example, if the delay is ten seconds, the clock waits for ten seconds each move before the base time starts going down. This timing method is mathematically equivalent to Bronstein delay. Simply delay is the form of delay most often used in the US while Bronstein delay is the form of delay most often used in most other countries.

Increment (also known as Fischer and bonus)—a specified amount of time is added for each move. For example, if the increment is thirty seconds, each player gets an additional thirty seconds for each move. Under FIDE and US Chess rules you get the increment for move one as well. For example, for G/3;inc2 (three minutes of base time with a two-second increment each move), you start with three minutes and two seconds on the first move. Not all digital chess clocks automatically give the increment for move one and thus for those that don't, the increment time has to be added manually to be base time so each player gets the increment for move one.

Bronstein delay—this timing method adds time but unlike increment not always the maximum amount of time is added. If a player expends more than the specified delay, then the entire delay is added to the player's clock but if a player moves faster than the delay, only the exact amount of time expended by the player is added. For example, if the delay is ten seconds and a player uses ten or more seconds for a move, ten seconds is added after they complete their move. If the player uses five seconds for a move, five seconds is added after they complete their move. This ensures that the base time left on the clock can never increase even if a player makes fast moves. As with increment, you get the delay time for move one under FIDE and US Chess rules.