1500 m

The metric mile, three and three-quarter laps. The start is a curved line with no lanes, so runners jostle from the first strides and the one boxed in on the kerb at the bell has a problem. Championship finals often turn on tactics rather than fitness: a slow first 800 hands the race to whoever has the best last 300 metres, a fast one rewards strength. Meeting races are a different thing, paced from the front for time, and most of the fast marks come from those. Times are recorded to the hundredth and no wind reading applies. The mile, 109 metres longer, survives alongside it as the only non-metric distance with a ratified world record.