I am super skeptical of this. i play sports, and talent is evident. I have played soccer for 20 years and never gone past upper intermediate level.

Yet, i have had younger people join, that didn't really know how to play, get really good. Their talent: They were super fast. Track athelete fast. They knew nothing about soccer, but after a year or two of playing, they became better than the players that had been playing for over 10 years.

Their advantage: Sheer speed, and fast reflexes. At some point the mantra 'if you try hard enough you will became great', becomes sheer lie. Some people, with given the same amount of training, or even less, became much much better...

But, hey, the '10k' hour rule type of books that give false hopes do sell, so the fradulent authors will keep em churning.,