system
A chat on subreddit /r/NoStupidQuestions
human
I’ll offer a couple more.

4. Black people (along with all people, of all races) are more comfortable and can achieve more in an environment where they feel comfortable and supported. So Black athletes will gravitate to environments where they feel comfortable and supported and represented, like basketball and football, vs other sports like racquetball and rugby. Or are you meaning to suggest that black people are GENETICALLY superior at football vs related sports like rugby? Does that really pass the red face test? 

5. Financial Support for youth sports in black vs white communities. Its rare to find well funded soccer clubs in black urban neighborhoods in the US, but you’ll find a lot of youth basketball leagues. Hence, 24% of major league soccer players (US and Canada) are Black vs 42% in the Premier league. Do you think there’s a GENETIC explanation for that? Or could there be some sociological factors at play, like better funding of youth football / soccer clubs for disadvantaged youth in the UK vs the US?

Number 3 is true, but I’d propose it’s due to a combination of factors such as stereotyping (including self-stereotyping leading to self-sorting— rare is the inner city black kid who dreams of being a polo player!— yet in the wake of Serena &amp; Venus we’re seeing a lot more Black women tennis players!), feeling comfort in certain environments leading kids to want to join more teams &amp; practice more, plus funding patterns for youth sports.
gpt
Also 6.  Basketball takes little money and space to play, making it ideal for poor urban areas, which also tend to be majority black.  As a result a disproportionate number of good players can be expected to come from such areas.