Let's put it this way--Federer is so dominant that there *has* to be a surface GOAT (against whom he's got a bad match-up to boot) in front of him for this discussion to be taking place at all. Many people still give it to Federer over Laver despite the fact that he's had to contend with the clay GOAT during his whole career. Had there been a few years' difference between Federer's and Nadal's careers, it wouldn't even be close and Fed would blow Laver out of the water (and I'm taking Laver's pro career into account). But yeah, the main points are obviously major titles (doesn't necessarily means GS titles only, depends on the times) on all surfaces and overall dominance. Federer tops both lists, so he's obviously a very strong contender for the title. I still prefer to use tiers, though, but to each his own.