American and No. 10 seed Mardy Fish says the gap between the world's top four men and the rest of the ATP tour has widened. No one outside of Nos. 1-4—Rafael Nadal, Novak Djokovic, Roger Federer and Andy Murray, respectively—has reached a Grand Slam final in the past three majors.

"[It’s] very strong. As far back as I can remember, it's as top-heavy as you've ever seen," said Fish after 7-6, 7-6, 6-4 win over Marcel Granollers at Wimbledon. "I mean, those guys have all the points. If you look back maybe five or ten years, I think I have like around 2400 ATP points, and I don't think that would put me in the Top 10. So those guys are doing well on every surface. It's not a fluke that you see the top four seeds almost every event in the semifinals, it doesn't matter where it is. Murray, any one of those guys could win the tournament. I wouldn't be surprised if any one of those guys did...Roger's Roger and Rafa's Rafa. Djokovic is playing as well as I've ever seen anyone play across the net, for sure."