Originally Posted by zagor
Depends on your definition of all time great, I'd say he's in the top 20.
Players who are out of their element on clay don't make 5 FO finals, win a FO title and 5 masters on that surface.
Federer did so in an era of homoginized tennis surfaces lacking in clay court specialists. Having said that, I would consede that Federer might be near the top 20 greatest of all time on clay, even though his game was largely neutralized and less effective on clay. But, he was/is no Vilas, or Nastase.