Bolt Supremacy

Beijing 2008, the 100 metres final: Usain Bolt slows down, beats his chest, metres clear of his nearest rival, his face filled with the euphoria of a young man utterly in thrall to his extraordinary physical talent. It is one of the greatest sporting moments. It is just the beginning.

Of the ten fastest 100-metres times in history, eight belong to Jamaicans. How is it that a small Caribbean island...