have u heard of Arthur Ashe ? He's a Black ppl representative in tennis world before Old McEnroe, before i knew tennis 20 yrs ago.
Now u can count on Monfils of France, just beat Roddick on the dirt (clay court)
Tennis is all Physical game, i don't know why Black's physic can't do well in this game. On the woman side, u have a couple of other black players from the US. Like Rubin and Alex Stevenson (a mix with NBA star father)
Maybe as the above poser said, $$$ is a factor. Rich guys can have their kids working on tennis. It takes million to make a tennis pro.