At the beginning of every mass start classic race, there are several points when the number of available lanes diminishes, and racers must scramble to find a new spot in the tracks. Starting lines 10-plus lanes wide must funnel down to two in a matter of a few hundred meters. Sometimes, a field of 100 athletes can make it through each transition with minimal collision. The men’s SuperTour 10 k classic in Lake Elmo, Minn....