Black guys and genetics...
Something tells me it has something to do with history. And should be more accurate: saying North-American black guys and genetics.
Think for a second of their history. It was a long process. Couple of centuries ago white people brought them into the new continent as slaves mainly from Africa. And they chose the strong, and genetically fit ones, so that they could work more and more effectively. During the decades (and centuries) number 2 'srceening' (or call it whatever u want, decimation) is that only the strongest ones could survive all the BS slavery meant to be.
This is something we know since Darwin, and which is called evolution. The same happened to the North-American black population, but it was artificially triggered and accelerated.
There are exceptions, for sure. But one can say just in general, that black guys have better genetics (especially for bbing) and it derives from the American history.