stop it. First you were specific that slavery was the cause of black athleticism, but then try to use generic talk like "came up hard" to reason why white foreign athletes supposedly dominate. No consistency, thus it is not true
Completely ignore the improve athletic training and the perceived lack of career options for some black community members and give credit to the "scientist" of that period, that were using cocaine, liquor, and heroin to treat ill patients
You are speaking like a person who is completely ignorant of the breeding practice. Breeding of anything does not produce guarantees. You could improve your chances for desired results if you include DNA manipulation, which obviously they were not doing during slavery
Don't cause confusion by injecting white supremacist ideologies along with conscious facts