quite obviously they are all very bright. it is just a question of who has the patience for it.
the top guns like Rafa and Federer have simply too much money and also too many other interests. I don't think they are going to stand at courtsides sweating over some players.
also there is no end in sight to the money that is coming in for Rafa and Federer. Federer is making $71 million a year now.
Rafa's 9-10 French Opens are worth a cool $1 billion over a lifetime. he is already wealthy beyond belief.
these two will do other things. Rafa will get into golf and poker. he may even try to buy a football club in Europe.