The Mundanity of Excellence: An Ethnographic Report on Stratification and Olympic Swimmers came up yesterday https://news.ycombinator.com/item?id=18442600 . It has interesting things to say about greatness. I wonder if what separates the very best of the best (e.g. Gretzky) from the best (professional Hockey Players) is analogous to what separates the best from everyone else. Or if it's just a matter of degree, not qualitatively different.