What Makes Generalists Successful in a Specialized World. The argument predates athletic competition. Are athletes like Serena Williams, Michael Phelps, and Usain Bolt genetic freaks sent to Earth to rule their specific sports? Or are they just regular people who, by sheer willpower and relentless practise, transcended their biological limitations? David Epstein takes on the classic nature vs. nurture issue in this contentious and compelling examination of sports performance and the so-called 10,000-hour rule, and he tracks how far science has come in finding an answer.