I can't help but suspect that the difference between, for example, good sprinters and great sprinters is not simply that Usain Bolt knew a guy who could get him some solid publicity to get his name out there as a great sprinter.
So it's exactly the same luck - nurture - dedication pattern. Of course, genes are how luck manifests for athletes, while knowing a radio DJ might be the singer's chance.
It still doesn't mean there was anything magical about Bolt or his training regime, or that his rise to 'greatness' was pre-ordained. He didn't have 'great' genes, he had good genes and he did everything right, avoided accidents etc. Just like other athletes, but his unique genes-training combination turn out to be the lucky one.