[AlexanderTheGr8]

I have often wondered : Why don't they attach a transponder on each athlete's center-of-chest (using some objective definition) and use that to time each athlete? That can be much much more accurate than any camera.

We can still use cameras for visual confirmation but transponders are much more accurate than any camera.

[stbtrax]

what wearable transponder has that kind of accuracy? ultrawideband is cm level in ideal conditions

[underlipton]

I'm not convinced they don't. If you look at Lyle's bib when he takes it off and shows it to everyone, there's something on the back. I thought it was another YuGiOh card at first, but then I thought, "That'd be the perfect place to put something to trigger some sort of check at the finish line."

[chedabob]

I suspect it's probably just easier for them to print all the race numbers the same way, but only use the transponder on races where it doesn't need to be accurate, or they need to take several measurements throughout the race.

For the longer distances, the lap times and finish times show up almost instantly when there's a big gap between athletes, although I believe there's a laser at the finish line too.

[dyauspitr]

Even if that is technically feasible that wouldn’t account for the lean, neck length etc. the center of the chest isn’t an accurate measurement given the current rules.