It seems that a lot of advisors out there would love to specialize in clients who are (or were) professional athletes. Who wouldn't want to spend all day working with stars and get paid for it?
The problem, of course, is that there actually aren't all that many people out there who've made it to the Big Show in their chosen sport -- and that if everybody's got the same idea, competition for each pro athlete gets pretty savage.
Still, there are advisors out there who have turned this into a viable business. Good profile of one of them over here.
The $2,500 subscription qualified lead database he used is here.
It's good to differentiate yourself as "the tennis advisor" or "the art advisor" or even "the antique car advisor" in order to capture a distinctive niche of client.
But unless you really love a particular sport, breaking into this one can be tough. Please let me know if you've done it.