The hundredth-of-a-second rule punishes the honest starter

Sprint starts are policed by a reaction threshold built on an assumption about human hearing that no longer looks solid.

A sprinter who leaves the blocks less than one tenth of a second after the gun is ruled to have false started. Not because anyone saw the athlete move early, but because the rule assumes nobody can hear a sound and produce force that quickly.

That assumption came out of laboratory work decades ago and it has been questioned ever since. There is evidence that some people, trained and unusually attentive, can respond faster than the threshold allows. If that is right, the rule occasionally disqualifies an athlete for being good at the one thing the start demands.

The practical consequence is worse than the philosophical one, and it shapes how sprinters actually race. Under a one-and-done disqualification, the cost of a marginally early departure is your entire championship. So athletes deliberately wait. They install a small hesitation, a fraction of a beat of insurance, and they train it until it is automatic. The rule does not just measure behaviour. It creates behaviour, and the behaviour it creates is slowness.

You can see it in the pattern of reaction times in major finals. They cluster comfortably above the threshold, and they have done for years, which is what you would expect from a field that has learned exactly where the electric fence is.

The counterargument is real and I have some sympathy for it. Before the current rule, meetings were ruined by athletes gaming the recall, breaking early on purpose to unsettle a rival who they knew would then be tentative. Somebody has to be punished for that, and a shared threshold at least applies the same standard to everyone in the lane.

Fine. But the fix should be a rule about intent and repetition, not a physiological constant borrowed from old research and treated as settled. Give the athlete a warning. Disqualify the second offence. Or lower the threshold and let the block sensors, which record the full force trace rather than a single crossing point, distinguish a genuine anticipation from a fast honest response. The data already exists in the equipment.

Instead we keep the number, because the number is simple and appeals get decided fast. And every year somebody who did nothing wrong walks off a track with a red card, having reacted too well to a gun.