I think there isn't. I started thinking about it when Mats Wilander said during Fed-Delpo, that the top 4 was expanding to a 'top 5', and I thought, then you can say there's just a top 30. I mean, there are four best players, but I think this is starting to be a weird time in tennis.. There is a clear no. 1, Rafael Nadal, but it's not like the top 4 are really separating themselves from the rest. Del Potro is not that far behind Djokovic in race points. Makes the semis of Roland Garros in Djokovic's quarter. Has beaten both Murray and Nadal this season and had Federer at the brink of elimination in a Slam. Roddick has beaten Djokovic twice this year, amongst which was a grandslam quarterfinal. Came as far as Rafa at Roland Garros, further than Novak, and came also further than both Novak and Andy Murray in Australia. Did not make at least the quarters of a tournament he participated in for the first time in Roland Garros. Matches up really bad to Roger Federer and lost three times already to him this season. other than that he lost just 4 matches. Verdasco kicked out Murray at the Australian Open, has been having great results and is constantly putting Nadal to the test whenever they play. Lost to Federer this season in a third set tiebreaker. Nadalhas already lost to Monfils, delPotro and Soderling Murrayhas lost to del Potro, Monaco, verdasco Federerhas lost to Wawrinka, came really close against Berdych, del Potro and Haas Djokovichas lost to Roddick twice, lost to Kohlschreiber, to David Ferrer, to Tsonga, to Nieminen, to Gulbis. I mean, sure they are the best 4 players in the world, but isn't there a bit too much hype about "the Big four". It's weird, yet great, times in tennis I think. We all think those top 4 players are 'easily' gonna win every single time and predict 'Rafa in 2' all the way. yet it's very very open right now. How big do you think the difference is between top 4 and the rest?