World number six Tomas Berdych has said that he is currently playing in the "best era" men's tennis has ever seen.
The 27-year-old Czech, who defeated Michael Russell in his first-round match at the Australian Open yesterday, believes that winning a Grand Slam title is now harder than it has ever been.
Only five of the current top 50 active players have won a major title, with two of those - Andy Murray and Juan Martin del Potro - winning just once.
"If you want to win the slam, you have to beat at least three of them, then it's really tough. That's how it is," said Berdych.
"Today's tennis is really, really strong. I think we were in the best era of our sport ever."
Roger Federer (17), Rafael Nadal (11) and Novak Djokovic (5) have won 33 Grand Slam titles between them.