[splat]

My understanding was that the claim was that the 10,000 hours rule was a necessary but not a sufficient condition for mastery. So any world class golfer will have played for at least ~10,000 hours, but not every golfer who has played for at least ~10,000 hours will be world class. The only way the hypothesis could be falsified is if Dan becomes a world class golfer in less than ~10,000 hours.