Centrowitz knew he was a long shot entering the 1,500 final, with a personal best nearly eight seconds slower than the fastest in a field that included Olympic champion Asbel Kiprop of Kenya. But he was friendly with Nick Willis, the Olympic silver medalist, who normally started toward the back. In this race, Willis took the lead early and allowed Centrowitz to draft behind him and conserve energy. Because championship races such as the Olympics

have no paid pace-setters,

the leader has to set the pace and battle

the wind while not being able to see

if he is about to be passed.