WRONG as can be on all accounts.
We have combines. At the combine we see which athletes are superior, and the NFL scouts judge accordingly. Beyond that, I can tell you as someone who coaches a sport in the inner city that there is huge purchase among African Americans in the cities when it comes to basketball and football. We can't get many kids to play soccer or baseball. They simply won't do it.
So I'm not talking GENETICS. I'm talking about both participation and performance (like the combine, for example).
AND, I'll say it again. There are no studies but flawed studies by white supremacists, as I've been over this is greater depth than you can ever imagine as it's part of my job.