As the Olympics are all about reaching peak physical potential, it shouldn’t surprise that a lot of races are close, but there’s been a good number of ties this year. The measurement system allows for precision up to the millionth of a second. So what gives? Timothy Burke for Deadspin provides the explanation.

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.

Always consider the bottlenecks.