NEW YORK • Youth may be wasted on the young and so it seems is the US Open, where half of the men's quarter-finalists are over 30 and two more have already celebrated their 29th birthdays.
This year's New York showpiece featured a record 40 men over 30 in the first round, up from 32 in 2014. The oldest was evergreen German Tommy Haas, the 37-year-old who was playing in his 17th US Open.
There were 10 teenagers - the most since the 12 who featured in 1990 - but only two reached the second round. No man born in the 1990s has won a Grand Slam title.
Roger Federer, 34, is the oldest man left. The five-time champion is due to face Richard Gasquet, 29, this morning (Singapore time) for a semi-final spot.
The 17-time Grand Slam title winner is playing in his 64th consecutive Major, a run stretching back to 1999. He believes his longevity is a result of making drastic changes to his schedule a decade ago.
"The idea was always to be around the game for a long time. In 2004, when I became world No. 1, I took a decision with my fitness coach at the time that we're going to plan long term," said the Swiss.
"Sure, we can chase money or more tournament victories. We can play more frequently, more often, train harder. But we decided we will try to stay around 20 tournaments a year, which is lower.
"If you look back, Yevgeny Kafelnikov used to play 30, 32 events back in the day. I said that's not something I really want to do."
Coming into New York, Federer had played just 12 tournaments this year, winning five titles.
Haas' career has been plagued by injury but he believes the physical strength of the older players is keeping them at the top of the game.
"A lot of things have changed with technology. Seems like sometimes the surfaces are a little bit slower, balls are getting heavier," he said. "It's gotten a lot more physical. Everybody is getting more fit, bigger and stronger and hitting with more velocity, more spin."
There are late bloomers too.
Kevin Anderson is set to play in his first Grand Slam quarter-final in his 27th Major this morning (Singapore time) when he meets Stan Wawrinka, 30.
The big South African will be 30 in May and he puts his late success down to a belated start to his professional career. He turned pro only in 2007 at the age of 21 after studying at the University of Illinois.
He said: "Going to college and turning pro a little bit later, I always felt myself a little younger than maybe some of the other guys my age who have been on the tour a little bit longer."