I am a Federer fan--I catch almost all of his matches, whether on TV or Youtube. But can we accurately label him the greatest? Mcenroe has done it, Sampras has does it. I've stated this before, but it is my belief that "GOAT" does not make much sense. To be the greatest of ALL TIME, one must've lived and played for ALL of TIME. In the game of tennis, there is only one empirical test of proof: what actually happens, ON the tennis court. Each player has to PLAY to prove his worth on court. Now Federer never played before 1981. How can we say he was the best player from 1971-1981? To be the best player in the world (in the ATP), one must win matches and week in and week out. That is the ultimate test of who is great at any particular time. Now we can make hypothetical match-ups: Federer vs. Borg, Federer vs. Laver... but these "scenarios" don't really make any sense at all. The context of each of these player's success was different. Laver... played in a era with both amateur and professional. Borg... played with wooden racquets. The conditioning was different. The competition was different. Think about how hard it is to compare Federer and Sampras? Who is better? Who would beat whom on which surface? We do not know, because they only played one close match. Perhaps a younger Sampras would have beaten him. Now on a more philosophical level: The very concept of GOAT is inadequate. It fails to recognize the differences between eras that are at heart inreconcilable. Tennis players can only be "great" for a few years of their life, maybe five years. By great I mean dominating the game. Roger has done this. This is a short amount of time. Now maybe Sampras was unbeatable for a month in 1996. Can we call him the greatest of all time based on that one month? No. See what I am saying? Just because Federer was amazing from 2004-2008 does not mean he is the greatest of all time. He was the greatest from 2004-2008. Because he PLAYED... and he WON.... Two things are needed... actual playing... and winning... over all of history... Til then, all one can do is be the greatest of his/her era.