The players i mention could beat Federer, but its not very likely, Murray in slams has no weapons vs Federer, and Nole can do it only on hard courts, RG/Wimby much less chance so you get my point.
When Federer is in good shape, Tsonga would not even make a brake, let alone winning or taking set. Like i said, Fed would destroy Tsonga this year.
djokovic is 50/50 on clay versus federer...at this moment in time i'd say he has the advantage
old legs don't have the stamina for clay anymore
those three players have limited federer to one out of the last 16 slams. it's clearly very likely
as i said, federer should be content. he has achieved almost all of the important all time records