Marginal Revolution asks what is the probability the person with the most chess aptitude in the world today actually knows how to play chess. The question is how much wasted potential there is out there because people with high aptitude never get the resources to take advantage of that aptitude.
I often think about this type of analysis when trying to figure out how smart Issac Newton was. Sure he had the most success of math as anyone of his day (by a bit, Leibniz discovered much of the same shortly after him), but he was only the best out of the very small set of people born who had access to the resources to become good at math. Let's say 100,000 at the most, or the top 0.001 percentile. Being in the 0.001 percentile these days means there are tens of thousands of people better than you at math in the world, and thus is probably not good enough to get you into a good graduate program in math these days.