Kimiko Date-Krumm is the oldest woman in the Australian Open draw at 42, with some competitors less than half her age still in high school.
Eleven teenagers advanced to the second round, compared with three in 2012. So many teenagers are moving up in the rankings that former No. 1 Caroline Wozniacki feels like a veteran at 22.
"There are still a few older ones than me," she said after beating 16-year-old Donna Vekic of Croatia in the second round 6-1, 6-4. "I still want to try to feel young out here. But, you know, it's the way of life, I guess — 22, it's old in the tennis world soon."
Just not yet. The next generation of female players have made a statement at the Australian Open, but there's no expectation they're ready to hoist a Grand Slam trophy like Martina Hingis and Monica Seles did at 16 and Serena Williams and Maria Sharapova did at 17.
Of the 11 teens in the second round, only three progressed — 17-year-old American Madison Keys, who took out 30th-seeded Tamira Paszek; 19-year-old American Sloane Stephens, who beat another 19-year-old, Kristina Mladenovic of France; and 18-year-old Laura Robson of Britain, who ousted eighth-seeded Petra Kvitova.
It's much tougher than it was a decade ago for a young player to break through and actually win a major. Part of the reason is the sheer physicality of the game today, a change brought by better training and conditioning, more powerful rackets and, of course, more powerful players like the Williams sisters and Sharapova.
Stephens plays Robson next in a potential glimpse of major finals to come.
"We're the same age, I guess it's a rivalry. I mean it's not like Federer-Nadal rivalry," Stephens said. She paused, before continuing: "It could be. We'll see."
Robson, the former Junior Wimbledon champion who will turn 19 next week, enjoyed a huge upset win over Kvitova on Rod Laver Arena.
She said after her victory that she definitely feels she's closing in on the top players.
"This year, you know, I set my expectations a bit higher," Robson said.
The British player climbed from No. 131 to 53 in the rankings last year, thanks to her impressive run at the U.S. Open where she defeated Kim Clijsters and Li Na en route to the fourth round.
Serena Williams, who easily beat 19-year-old Spaniard Garbine Muguruza in the second round, isn't ruling out another teenage Grand Slam winner. She thinks Keys has the game and the poise to do it.
"I think it will happen again probably soon," she said. "I think if the person is strong enough physically and mentally, I think it's completely possible."
"Madison Keys is like 6-foot-2, and she's very strong and she's only 17. She has several years while she's still a teenager to win a Grand Slam."
Vekic reached her first WTA final in Tashkent, Uzbekistan, last year at 15 — the youngest WTA finalist in seven years — and was the youngest player in the main draw at the Australian Open.
These days, teenagers are restricted in how many top-level tournaments they can play, a change enacted in response to Jennifer Capriati's troubled teen years. Capriati struggled with the pressures of the tour after cracking the top 10 at 14 and left the sport, burned out, at 17. She began a successful comeback two years later.
Players younger than 15 are mostly prevented from playing at the WTA level, while those between 15 and 18 are limited in the number of tournaments they're allowed to play. The effect is teenagers are staying at the junior level longer, making it tougher for them to eventually make the jump to the top flight.
Although most lost their second-round matches at Melbourne Park, the younger players did show tremendous potential. Under a blazing sun on Court 7, 18-year-old Yulia Putintseva, who was born in Russia but represents Kazakhstan, lost a tight three-setter to Spanish veteran Carla Suarez Navarro. She fought to the very end, pumping her fists and punctuating every point with a ferocious "Come on!"
On the court next to her, fellow 18-year-old Daria Gavrilova of Russia was locked in a tense match with Ukrainian Lesia Tsurenko. Shuttling between the two was Hingis — the youngest Grand Slam champion of the 20th century — who has been helping both players as a coach at the Mouratoglou Tennis Academy outside Paris.
After her match, Putintseva alternated between giggles and confident boasts about her future. She said she was working on controlling her temper and was proud she didn't break any rackets on Thursday.
"In a match like this, I would (normally) break five," she said, laughing.
Putintseva also feels ready to move beyond the juniors, which she has found limiting. "I think I have the level to play already these (Grand Slam) tournaments," she said. Part of the reason is Hingis, who has been helping her learn to handle the pressures of the sport.
"I hope that she'll continue to work with me and we try to win a Grand Slam together," she said, with more giggles.