The immortal of Australian tennis, Rod Laver, says he can't see an end to the stunning career of Roger Federer, who he believes is playing as well as he ever has.
The Swiss champion prepares to fight for his 20th major at the Australian Open on Sunday, which would stretch his lead for the most singles titles of any man.
At 36, Federer hasn't dropped a set in his progression to the final against Marin Cilic.
Laver, who has watched Federer's progression at Melbourne Park this year, is convinced he hasn't seen better tennis from the all-time great.
"He's certainly playing as well as he did eight or 10 years ago," Laver told AAP.
"I wouldn't say he's better but Roger is playing some of his best tennis.
"Not all the time maybe. But pretty close to all the time."
Laver's assessment puts the Swiss champion's current form on par with one of his most dominant periods.
A decade ago, Federer was in the middle of an incredible streak of reaching 18 of 19 consecutive grand slam finals - between Wimbledon in 2005 and the 2010 Australian Open - with his 2008 appearance at Melbourne Park the only blot on his run.
Laver would know greatness.
The sport's indisputable No.1 at the dawn of the Open era, finished with 11 majors - including the coveted calendar year grand slam in 1962 and 1969.
Federer has called the Queenslander his idol, helping found the Laver Cup in tribute to the Australian champion.
The Californian resident will again be in the stands when Federer attempts to chalk up major No.20, and says he has seen Federer evolve as a player over the journey.
"He's playing smarter," he said.
"You learn when you're playing an opponent or you see him a lot, he sees weaknesses that other people don't see.
"That's the difference between Roger and the field.
"The rest plays their game. That's a big advantage."
Given his spectacular assessment of Federer's position in the sport, it's no surprise that Laver doesn't see him pulling up stumps any time soon.
"He's enjoying it more. It's another edge," he said.
"When he's hitting a backhand down the line, if he sees that happening still that will keep him going for another year."