> from sports i know (hockey), generally the next generational player is identified when they're like 12-13 years old (earlier for Gretzky).

Yeah, I'm really unconvinced by the paper.

1) Adult chess GMs all come from super advanced kids, now. Period. GM Ben Finegold talks about this at length.

2) We know that, for example, hockey success is correlated with birth month. This means that juniors who happen to be slightly larger and promising get more attention and coaching and so wind up being the world class adults, too.

I could be more convinced by academics and music that you need multi-disciplinary education to be world class, but I'd need to see a lot more evidence.

Nevertheless, the single thing I extract from my anecdata is that being top ten in a world class field requires a dedication bordering on psychotic mania. You have to be willing to not just go the extra mile but the mile beyond that and beyond that and ...

Most people are completely put out by the minimal amount of effort to get to the top 1% so they would be stunned by the amount of work you have to put in to get to top 10.