How the stop the clock game works
Each round shows a target time, like 3.500 seconds. Press Start and the clock counts up fast. Hit Stop the instant you think it has reached the target. Your miss is how far off you were, in milliseconds — and after five rounds your score is the average of all five. It's pure timing precision: no waiting for a random signal, just you against the clock.
What is a good score?
- Over 400 ms — still getting a feel for it.
- 150 to 250 ms — a decent sense of timing.
- 40 to 90 ms — sharp; you're reading the clock well.
- Under 40 ms — bullseye territory.
Tips to stop closer
- Watch the tenths, not the thousandths — the last digits move too fast to track.
- Pre-load the press so your finger fires the moment the tenths flip.
- Note early vs late — the game tells you which, so adjust on the next round.
Like timing challenges? Try the reaction time test or audio reaction test.
Frequently asked questions
How is Stop the Clock scored?
By your average miss across five rounds. Each round measures how far your stop was from the target, in milliseconds, and lower is better.
Is this the same as a reaction time test?
No. A reaction test measures how fast you respond to a surprise signal. Here you know the target in advance, so it tests timing precision and anticipation instead.
What is a good stop the clock score?
An average miss of 150 to 250 ms is decent, 40 to 90 ms is sharp, and under 40 ms is bullseye level.
Does it work on a phone?
Yes. Tap Start, then tap Stop when the clock hits the target.