I don't think that Epstein is being very charitable with Gladwell's 10,000 figure. Gladwell: a) Doesn't make the 10,000-hour figure a rule as both Epstein and Repanich would have us believe. b) Fully concedes that there are myriads of other factors that have an effect on how one reaches "expert status". I'm also not sure how Epstein can claim that the chess master study is somehow disanalogous with the athlete one. A…
The problem is that the chess study shows that some people never became chess masters, no matter how many hours they practiced. There was a hard upper limit to their performance that no amount of training could surmount. Insofar as "expert" is defined by relative ranking, some people will never become experts. Why? Because they are outranked by the "naturals". The general problem with the Gladwell/Ericsson hypothesis…
In some (marginal) cases, you lack a necessary feature of being an expert in X. I don't see how this breaks Gladwell's position.