This weekend marks one hundred years since the first driver put tires to the starting line at the Indy 500, America’s most competitive car race. Sports writer Charlie Leerhsen is the author of “Blood and Smoke, A True Tale of Mystery, Mayhem, and the Birth of the Indy 500.” Leerhsen discusses a century’s worth of squealing tires and helps solve a lingering mystery from the Indianapolis Motor Speedway’s very first race.