For years I have played table tennis, and seen various young, talented and ambitious players rise through the ranks, sometimes to a point where they played in t

For years I have played table tennis, and seen various young, talented and ambitious players rise through the ranks, sometimes to a point where they played in the men's leagues at 14 or 15 years, because there wasn't much competition in the youth leagues. And while I didn't count them, I'd say that about two thirds of them stopped progressing (and then playing) somewhere between age 16 and 18. Mostly they developed other interests, or lost motivation for reasons unknown to me. So I'd be very careful with putting high stakes on very narrow interests; it can easily become a dead end. (FWIW I don't consider that time "lost" or anything; they surely learned a lot about self confidence, team play, reliability and other traits; it's just that it sounds that you as a parent might be rather disappointed when your hypothetical child loses interest in his narrow focus).