Using the word talent makes it more problematic. The key is whether variation in skills are completely determined by environment or are partially determined by genes. Those skills can be fully or partially cultural specific, but the question remains as to whether genes play zero role in variation. The answer may vary for varying skills, but it seems really unlikely that none of the skills we value in which extreme variation is noted have that variation influenced by genes. I was born the same year as Magic Johnson. No doubt part of the reason he played basketball better than I do was because he worked a million times harder at the game than I ever did. But I'm five foot seven, and have genetically poor coordination. But is there any reason to believe that any amount of hard work have turned me into the player Johnson was?
Mind you your point about intelligence is relevant too. A lot of people don't appreciate how important intelligence is to athletics, how much being really good at a competitive sport requires split second decisions making and tactical planning. Being good at basketball or football or karate is a kind of intelligence. Years ago I heard one coach say to another "Yeah, he is quick. But, how quick is his quick."