(This is all over the web, but is absolutely worth your time.)

Deadspin noticed that swimming has lots of ties, which is weird, so they asked why. The answer is really amazing: Turns out, swimming isn’t timed to the thousandths of a second — unlike many other events — because of the imprecision inherent in pools. The lanes themselves may vary by more than the length a swimmer can travel in a thousandth of a second, so timing at that level would be bullshit anyway:

In a 50 meter Olympic pool, at the current men’s world record 50m pace, a thousandth-of-a-second constitutes 2.39 millimeters of travel. FINA pool dimension regulations allow a tolerance of 3 centimeters in each lane, more than ten times that amount. Could you time swimmers to a thousandth-of-a-second? Sure, but you couldn’t guarantee the winning swimmer didn’t have a thousandth-of-a-second-shorter course to swim. (Attempting to construct a concrete pool to any tighter a tolerance is nearly impossible; the effective length of a pool can change depending on the ambient temperature, the water temperature, and even whether or not there are people in the pool itself.)

Fascinating.