Eliud Kipchoge

Kipchoge beat Bekele and El Guerrouj to win the 2003 world 5,000m title as an 18-year-old, then spent a decade as a fine but beatable track runner. The marathon unlocked him: his calm, metronomic rhythm and patience suited 42km far better than a last-lap sprint. Two Olympic marathon golds and two official world records followed, which makes him the strongest case on this list that some track runners are really marathoners waiting to happen.