The child prodigy has virtually disappeared in tennis, making it difficult to identify the top teenage prospects in tennis today.
Not long ago, teenagers dominated the sport. Martina Hingis was ranked No. 1 in the world at the age of 16, and Bjorn Borg, Rafael Nadal and Boris Becker owned two Grand Slam titles apiece while they were still in their teens.
Today, there are no teenagers ranked among the top 30 women, and none are among the top 200 men.
There are several who may emerge in the near future. You just have to dig a little deeper to find them. Most of the promising teenagers are among the women, with four teens ranked among the top 50 females.
We selected 12 promising teenagers and counted down to the top prospect.
Italy's Gianluigi Quinzi won the 2013 Wimbledon junior title.
In January 2013, at the age of 16, the left-handed Quinzi was the No. 1 ranked junior in the world. He currently stands at No. 3 with another year of junior eligibility remaining.
He won a Futures tournament in Morocco in June and reached the finals of two other Futures events earlier in 2013. All three were on clay, which made his victory at Wimbledon more significant.
Alexander "Sascha" Zverev was not among the world's top 100 juniors in 2012, but he has jumped all the way to No. 2 this year.
What makes Zverev intriguing is that he is just 16 years old.
His aggressive baseline style seems best suited to clay, and he reached the finals of the French Open junior tournament this year.
Both his parents played professional tennis, and his brother, Mischa, currently plays on the pro tour and was ranked as high as No. 45 in 2009.
Garbine Muguruza turns 20 in October, so she barely qualifies. Plus she had ankle surgery in July and will not play the rest of 2013.
But the 6'0" Muguruza offers intriguing potential with her size, big serve and powerful groundstrokes.
Born in Venezuela and raised in Spain, Muguruza has provided glimpses of greatness. This year, she beat No. 18-ranked Dominika Cibulkova on grass in June and knocked off No. 9-ranked Caroline Wozniacki and No. 19 Ekaterina Makarova on hard courts in March.
Muguruza first got attention in March 2012 when she upset Vera Zvonareva, then ranked No. 9, on hard courts in Miami.
Although she is ranked No. 61 at the moment, the layoff following surgery no doubt will stymie her progress when she returns. But she may learn to take full advantage of her physical gifts as she matures.
Eugenie Bouchard gained attention by beating No. 12-ranked Ana Ivanovic to get to the third round at Wimbledon this year.
"That was very impressive," Martina Navratilova said on a broadcast following that victory, according to the Toronto Sun. "If she continues like this she will be top 20 at least by the end of the year. I don't want to say a star is born, but we have seen a potential Grand Slam champion here."
Bouchard, a Canadian, also won a round at the French Open before losing to Maria Sharapova.
Bouchard owns a win over a top 10 player in 2013, beating No. 9 Samantha Stosur in Charleston, S.C., in April. However, that victory was tempered by the fact that Stosur was limited throughout by a calf injury. Stosur eventually retired from the match while trailing 6-1, 2-0, according to the Charleston Post and Courier.
It still represented a confidence-building victory for the 19-year-old Bouchard.
“I try to control the point with my serve," she said after that victory, according to the Post and Courier. "I think I did that well tonight, the first ball of the point, really tried to control it and even with the return as well, I was really trying to attack her serve, and I think really being aggressive and not hesitating to come forward.”
Her ranking got as high as 55th in July, and she is now at No. 62.
Australian Nick Kyrgios is the No. 1-ranked junior player in the world, and he is just beginning to play men's tour events.
Kyrgios, 18, gained notice by beating Radek Stepanek at the French Open this year.
"When you're good in the juniors, it doesn't mean you're automatically going to be good in men's tennis," Stepanek said, according to theguardian.com, after losing to Kyrgios. "But definitely he has some talent. He's serving big and if he keeps working hard, he definitely has a chance."
Kyrgios' victory over Stepanek, whose ranking had slipped to No. 52, is his only win of note on the ATP World Tour. Kyrgios is still ranked outside the top 200.
Kyrgios' former coach Todd Larkham told the Canberra Times:
If you look at the top juniors from Europe most of them have made it, but we've had too many Australian juniors probably over the last 20 years who haven't made it. I'm very confident [Kyrgios] is going to be top 100 and we'll see after that how good he can be. He's got a huge game, he's got a great first serve, he plays extremely aggressively. I compare him to [former World No.1 Andre] Agassi really, he takes the return of serve extremely early, and he plays in a very aggressive game style.
Annika Beck, the 2012 French Open junior champion, won a round in each of the first three Grand Slam events in 2013.
Beck, a 19-year-old German, beat 28th-seeded Yaroslava Shvedova in the Australian Open. However, her best showing this year may have been her 7-5, 6-7, 6-3 loss in Stuttgart in April against Petra Kvitova, who was ranked No. 8 at the time.
This is Beck's first year on the main tour. Twelve months ago, Beck was ranked 142nd. Now she's up to No. 46.
She is still inconsistent, losing some matches to players she should beat. But that is not unusual for players new to the tour.
Belinda Bencic won both the Wimbledon and French Open junior titles this year and is the world's No. 1-ranked junior female by a wide margin.
She had won six straight junior tournaments throughout the world before losing in the semifinals of the European Junior Championships in late July in Switzerland.
And she is just 16 years old.
Bencic is coached by Melanie Molitor, who is Martina Hingis' mother and was also Hingis' coach throughout most of her career.
"She makes me work very hard for sure,” Bencic said of Molitor, according to the New York Times. “She’s very tough on the court, and she wants me to do what she says, but she’s very encouraging too. It’s all about getting everything a little bit better.”
Bencic is already absorbing the fine points of the game from Molitor.
"It is that cerebral quality of Bencic’s tennis that makes her stand out, rather than just her sweetly timed backhand," the New York Times reported.
Impressive performances in the French Open and Wimbledon have put the spotlight on Puerto Rico's Monica Puig, who turns 20 on September 27.
She beat 11th-ranked Nadia Petrova while getting to the third round at Roland Garros. Puig was even better at Wimbledon, beating fifth-ranked Sara Errani 6-3, 6-2 in the first round and advancing to the round of 16. Puig provided a challenge to 17th-seeded Sloane Stephens before losing 4-6, 7-5, 6-1 in the fourth round.
Those performances in Puig's first two Grand Slam events demonstrated she is capable of playing her best on the big stage on different surfaces.
Puig made use of her big serve and aggressive style to produce 38 winners against clay-court specialist Errani. Puig also showed her mental toughness by winning the match after letting five match points slip away.
"Mentally, physically it just all comes together," she said after the victory over Errani, according to Associated Press (via Sports Illustrated.com). "Before this year, I had a really tough loss to (Angelique) Kerber in Brisbane and wasn't able to close that one out. But obviously losing that match was probably one of the best lessons for me because I ended up learning from it and closed off some pretty big matches."
Puig is ranked No. 53 after being outside the top 100 in April.
Big things have been anticipated for Ukrainian Elina Svitolina ever since she won the 2010 French Open junior title at age 15. This summer she's starting to fulfill those expectations.
Svitolina became the first teenager to win a WTA title since February 2012 when she won the Baku Cup last month, according to UPI.com.
The 18-year-old Svitolina backed that up by winning a second straight WTA tournament, claiming the title at Donetsk, Ukraine, in early August.
She did not beat a player ranked in the top 60 in either, but her consistency in those two minor hard-court events suggests she could pull an upset in the U.S. Open.
Svitolina won a round in the 2013 French Open and had tough draws in the other two majors in 2013. She lost in the first round at Wimbledon to eventual champion Marion Bartoli 6-3, 7-5 and was eliminated in her opener at the Australian Open by No. 5-seed Angelique Kerber.
A big serve and powerful groundstrokes have enabled Svitolina to win her last 10 matches in a row, moving her quickly up the rankings.
Entering June of this year, she was ranked 90th. Now she's 44th.
Donna Vekic just turned 17 in June, and she has already reached the finals of two WTA events, according to Associated Press.
Vekic lost in the first round of both the French Open and Wimbledon this year. Her loss to qualifier Petra Cetkovska in her opening match at Wimbledon was disappointing after she had beaten three top 50 players on the grass at Birmingham in her preceding tournament.
However, Vekic is down just three spots from her career-high ranking of 62nd achieved in mid-July. She is the youngest player among the top 100.
She uses hard, flat groundstrokes to keep opponents on the defensive, which is not surprising for someone who says Chris Evert is her idol, according to the Daily Mail.
She is coached by David Felgate, who once coached Tim Henman.
"‘He is the main reason for my success," Vekic said of Felgate, according to the Daily Mail.
Vekic got to the second round of the Australian Open as a 16-year-old and impressed Caroline Wozniacki, who eliminated her in the second round in Melbourne.
“I believe that we're going to see a lot of her in the future," Wozniacki, a former first-ranked player, told the Sunday Times of London. “She’s a very tall girl [5'10"] and she’s young. She’s going to improve a lot over the next few years still. I definitely saw a lot of potential in her."
Three-time Grand Slam winner Lindsay Davenport may have announced Madison Keys' arrival when she said in a January tweet that Keys has "incredible potential," according to The Guardian. "Best hope I've seen for US since Williams."
That was after Keys got to the third round at this year's Australian Open. But she had begun turning heads the previous week in Sydney.
Keys then defeated the No. 6-seed Li decisively at the French Open in May to provide evidence of her potential.
Keys backed that up by getting to the third round at Wimbledon before losing to fourth-ranked Agnieszka Radwanska in three sets.
Keys is ranked No. 41 at the moment.
Keys, 18, turned professional at 14 and gained attention that year by beating Serena Williams in a World Team Tennis Challenge match in 2009.
Keys knew the match didn't mean much to Williams, but it was important to Keys.
"She obviously wasn’t going full out, it was first to five, no advantages, people cheering, your bench is on the side of the court, it was definitely not a competitive match," Keys told the Birmingham Mail. “But I think that was probably one of the best five or six games I have ever put together."
A shoulder injury has caused Keys problems during the summer hard-court season. She withdrew from tournaments in Toronto and Cincinnati because of the ailment, and she has struggled in other events since Wimbledon. She hopes to be healthy for the U.S. Open.
Laura Robson is the top female player in Great Britain and is the highest ranked teenager in the world. Robson, who will turn 20 in January, is currently ranked No. 31 after being as high as 27th last month.
She had four wins against top 10 players over the past 12 months, plus a victory over Venus Williams. Three of those top-10 wins came in Grand Slam events, demonstrating her ability to perform in big events. She got to the round of 16 at Wimbledon and seems on the verge of producing an attention-getting victory over a name player.
She dropped out of the hard-court tournament in Montreal because of a wrist injury, according to BBC Sport. If that is healed she could be ready to make a splash at the U.S. Open.
Martina Navratilova is among those who think Robson has the ability to win a Grand Slam title.
"I'd say Laura Robson will go on to be a top-10 player for sure, maybe top five," Navratilova told BBC Sport. "She does so well on the big stage against the top players. She raises her game, which is great to see. She just needs to beat the players she should beat, more often. That is what has perhaps held her back. Some people have that mentality to beat the best and some don't, it's that simple. You can't teach it."