The individual subjects being the only things existing is exactly what I've been arguing. And the blurring of ethnic/racial lines does mean that the groups don't really exist.
And you're an idiot, because if I (or any intelligent person) were betting they wouldn't factor in skin color at all, they'd use track record.
And even if you did go based on color, your thought is still dumb, because virtually all 100m sprinters are black and all swimmers are white. Your assertion that you would bet on the race that virtually all persons in that sport are doesn't add any value to the betting selection. You essentially you just claimed you'd bet on everyone.
And even if that weren't the case, the assertion is still dumb because you are apparently forgetting that skin tones go across the spectrum and can even change due to diet or sun exposure. There is no black/white line in skin tone. Are you asserting that the darker a persons skin is the faster they can run on average? So if there were 2 people of African dissent, you would bet on the one with the darker skin?
Also, are you aware that the black race has genetic groups that are essentially on opposite ends of the spectrum when if comes to muscle composition and explosive power generation? There is a large population of black genes that are terrible for explosive running?
You have no idea what you are talking about.