I think it was Outliers (Malcolm Gladwell) that talked about a similar concept as well. Ignoring the 10k hour thing, it also talks abut small compounding advantages that later add up to more opportunity (for those that take it).

To go with the sports analogy, (paraphrasing, been awhile since I read it) it mentions how birth date coinciding with the youth sport season was a strong determiner of success at that sport because being ~11 months older in the same age group meant they were bigger faster more experienced and would be played more, compounding increases in skill.

There was also a similar concept floating around about darts, where the poor get maybe one dart to throw, middle class a few and wealthier get many. But I can't remember where I saw or read that