My son is not quite three, so obviously we are okay with him playing whatever, but yes he is obsessed with sports. He talks sports, he wears almost only sports themed clothing, he plays at different sports all day. He can hit a pitched baseball really well and apparently is getting quite good at golf (I let daddy enjoy the obsession while DD and I do Shakespeare etc, ha). It can get wearisome, but it helps motivate him easily, too. I did order some sports themed pens etc for Xmas because I would like him to say color or scribble a little sometimes. He's always been so physical, since a babe. So different from his sister, and we really tried to be anti-sexist. They just have their obsessions and predispositions!