Andre Agassi believes Rafael Nadal can make a claim as the greatest player of all time. But when it comes to comparing Roger Federer and Agassi's old rival Pete Sampras, the eight-time Grand Slam champion says Federer is on a different level.
"I think Federer is a class above, quite frankly," Agassi told HuffPost Live. "You're talking about a guy who dominated pretty much on every surface, minus one guy [Nadal] on clay. He's won everything."
Federer broke the record for Grand Slam titles he shared with Sampras when he won his 15th, at Wimbledon in 2009. The 32-year-old Swiss also surpassed Sampras' record of 286 weeks at No. 1 after reclaiming the top spot following his 17th major title, at Wimbledon in 2012. Federer has 77 career titles and Sampras has 64.
Agassi favors Federer because of his all-court prowess.
"Pete was obviously off the hook on faster courts, but during the clay season players wanted to play against him," Agassi said. "It was an opportunity to get a win over him. You didn't have that luxury with Fed. He was really the world-class, all-around player. Until Nadal, you would say that Fed is probably the best of all time."
Nadal, 27, has 13 major titles and owns a 21-10 record against Federer.
"Nadal has an argument to make for the best of all time," Agassi said. "If Nadal is sitting at a table with Federer and Federer says, 'I'm the best ever,' my first question would be, 'Well, then how come you didn't beat me, because I beat you twice as many times? And, hey, by the way, you know I won everything, including a gold medal [in singles at the Olympics] and Davis Cup [with Spain].'
"But at the same token, Federer has separated himself during a few years like nobody else. And he's done it more consistently. To be able to make the argument for both guys playing in the same generation is pretty remarkable."
Agassi, who won all four Grand Slam tournaments, finished with 60 titles and spent 101 weeks at No. 1, doesn't put himself in the greatest-of-all-time conversation. "It's not even close," Agassi said. "I'm way down the list from guys like that. I did manage to win all of [the Slams], but that's just the first criterion in my mind. ... For me, those two [Federer and Nadal] and [Rod] Laver are in a whole other tier."