The difference between an Olympic winner and the 4th place finisher in sports like Track & Field, Olympic weightlifting, Swimming and Cycling is less than 3%. Typical basketball games are often decided by less than a single basket. The difference between a home run and an out can be as little as a couple inches. Given that outcomes in sport are decided by such small margins why would you be willing to train with anything less than the best. Is being good good enough?