The first accepted pointer press starts the high-resolution browser clock and counts as click one. The test uses the exact deadline instead of trusting interval ticks, so a delayed screen update cannot extend the scoring window. Inputs at or after the deadline are excluded.
The first press also locks the attempt to mouse, touch, or pen. That keeps synthetic compatibility events and a second input type from inflating one result. Your personal best for each duration and input type stays in local browser storage. No score is uploaded.