I think we have seen three of the all time greatest male tennis players all playing at the same time in Federer, Nadal and Djokovic - which was a bit of a bummer for Andy Murray I suppose. Doesn't mean Djokovic should be given any special treatment by the Aussies though and if he has not the correct certification then he should be out - and I see they are now also looking at other players too. Re Rod Laver yes I think he'd be up comparable with those three. Some folks would only count majors won and he is way below them all on that but he lost about 5 years of playing in Grand Slam tournaments in what would have been his peak years because of being banned because of his professional status. That is a possible 20 Grand Slams where he was not allowed to add to his eventual tally of 11 wins.