Increment vs Delay: Fischer, Bronstein & Simple Delay
Time controls · The mechanics · Updated 2026-07-10
Every chess clock setting is one of five mechanisms. Two of them - increment and delay - are constantly confused, and the difference decides whether your time can grow or merely stop shrinking.
Here's each one, with the exact math.
The five mechanisms
| Mechanism | How it works | Can time accumulate? |
|---|---|---|
| Sudden death | Fixed time, nothing added | No |
| Fischer increment | +Y seconds after every move | Yes |
| Bronstein delay | Up to Y seconds returned after the move | No |
| Simple delay | Y-second countdown before main time drains | No |
| Hourglass | Your used time flows to the opponent | Yes (from opponent) |
Fischer increment: time can grow
After each of your moves, Y seconds are added to your clock - move in 2 seconds on a 5-second increment and you're 3 seconds richer. Invented by Bobby Fischer, it's FIDE's standard (30 seconds in classical) because it guarantees you always have time to physically make a move, and it rewards fast, confident play.
Bronstein vs simple delay: the same grace, shown differently
Both give you Y free seconds per turn, and neither lets time accumulate. Simple delay (the US Chess standard, usually 5 seconds) counts the grace period down visibly before your main clock starts draining. Bronstein runs your main clock immediately, then adds back what you used up to Y - mathematically identical, visually smoother. Take 3 seconds on a 5-second Bronstein and you get 3 back; take 20 and you get exactly 5.
Hourglass: casual chaos
Time you spend flows into your opponent's bank, like flipping a sand timer. Nobody plays it seriously - everybody should try it at least once. It's brilliant for casual board-game nights.
Set any of them in seconds
The app's time-control picker lists all five mechanisms plus multi-stage tournament formats, each with a one-line explanation right in the picker - the same wording tournament players use. Pick minutes, pick seconds, save it as a preset, done.
All six time controls, correctly implemented. Fischer, Bronstein, simple delay, sudden death, hourglass, and multi-stage - free 7-day trial on the App Store. Download Chess Clock: Board Game Timer on the App Store.
Frequently asked questions
What's the difference between Fischer and Bronstein?
Fischer adds the full Y seconds after every move, so quick moves grow your clock. Bronstein returns only what you actually used, capped at Y - your clock can never exceed its previous reading. Fischer accumulates; Bronstein doesn't.
What does 'd5' or '5-second delay' mean in US tournaments?
Simple delay: each turn, a 5-second countdown runs before your main time starts draining. US Chess events use it as the standard for sudden-death controls - 'G/60 d5' is 60 minutes per player with a 5-second delay.
Which is better for beginners, increment or delay?
Increment. Beginners burn clock in endgames, and a 5-10 second increment means the game is decided by the position, not by who can physically move faster. 15+10 rapid is the classic training control.
What is an hourglass time control?
Both players start with the same time (say 3 minutes), and time you spend thinking is added to your opponent's clock. The total stays constant; the pressure oscillates. It's a casual format - fun, fast, and legal in exactly zero tournaments.