I think you have to start very young in most sports now, not just tennis. I know...

joshhart on Sept 1, 2011 | parent | context | favorite | on: "He started programming when he was 6"

I think you have to start very young in most sports now, not just tennis. I know swimming is that way, and Michael Phelps is a bit of an exception because he started training at the late age of 7!