Tennis experts offer advice on how young women can improve their games and move up in the rankings.When Ash Barty retired in March, the conversation centered on how someone so young could walk away from tennis. For a Women’s Tennis Association champion, however, 25 is relatively old.Since Serena Williams’s last Grand Slam title at the Australian Open in 2017, 15 of 19 Slam winners have been 25 or younger, and 11 were women no more than 23. The new world No. 1, Iga Swiatek, won’t be 21 until the end of this month.However, most of that group failed to ensconce themselves at the top of the sport: Jelena Ostapenko, Bianca Andreescu, Sofia Kenin and, especially, Garbiñe Muguruza and Naomi Osaka are still threats, but all have Ping-Ponged up and down the rankings because of injuries and other struggles.That opens the door to the Top 10 for the next generation. But to reach the sport’s summit, these players must address their weaknesses. However, as the American player Coco Gauff noted, “It’s tough to work on new things when you’re practicing during a tournament because you don’t want to introduce something new just before a match.”Marta Kostyuk and Amanda Anisimova said they skipped tournaments, sacrificing ranking points, to make time for practice. “I have a good balance,” Anisimova said. “My game is a work in progress, and it’s not a speedy process.”Pam Shriver, an ESPN analyst and former professional player, said that in the late fall, players out of contention for the year-end WTA Finals would be well served by taking more time off. “They should each do a major assessment after the U.S. Open to see if they want to retool a few things,” she said.They should learn to emulate Barty’s well-rounded game, said Martina Navratilova, a Tennis Channel analyst and the multiple Grand Slam winner. “She had variety in her shots and a Plan B or Plan C in every match,” Navratilova said. “You have to be able to hurt people in more ways than one.”Fortunately, said Rennae Stubbs, an ESPN analyst and former professional player, the competitors’ youth allows time to grow: “Yes, there are things they can improve, but the great players from the past all changed how they played as they got older and stronger.”Here are seven players no older than 22 and advice on how they could improve their games.Emma Raducanu at the Madrid Open tennis earlier this month. Manu Fernandez/Associated PressEmma RaducanuLast year, Raducanu, 19, who is ranked 12th, stunned the sport by winning the United States Open. But instant stardom can create problems, Navratilova said.“She’s getting thrown too much into the world outside tennis,” Navratilova said of distractions like social media. “And agents often try to get the bucks while the player’s hot.”Shriver, who reached a U.S. Open final at 16, can relate. “It changed my whole world,” she said. “It takes awhile to get resituated with your new identity and responsibilities.”Coco Gauff at the BNP Paribas Open in Indian Wells, Calif., in March,Mark J. Terrill/Associated PressCoco GauffGauff, 18, and ranked 18th, is working on her footwork and on staying calm under pressure, “making sure I take my time between points,” she said.Her elders prefer that she focus on her forehand. “It has gotten better, but it’s still the shot that goes off,” Navratilova said.Stubbs blamed Gauff’s extreme forehand grip, exacerbated by a long swing and not enough racket-head speed.For an athlete of Gauff’s caliber, time may provide the solution, Shriver said. “When you’re still growing into your body, it’s not easy to always have the same contact point on shots,” she said, “so some of this will change when Coco settles into her frame.”Leylah Fernandez in April playing in Vancouver, Canada. Darryl Dyck/The Canadian Press, via Associated PressLeylah FernandezHer top priority, Shriver said, should be building up durability and strength: “She needs a strong core to withstand the power of the top players but also the week-in, week-out playing.”As a lefty, Fernandez, 19, and ranked 17th, must also use her cross-court forehand to pull players off the court on their backhand side, Shriver said, and earn more free points on her serve, Stubbs added. “Her service motion could get a little more fluid,” Stubbs said. “It gets a little discombobulated.”Amanda Anisimova at the Australian Open at Melbourne Park in January.Dean Lewins/EPA, via ShutterstockAmanda AnisimovaAnisimova, 20, and ranked 33rd, has the shots to be a champion, Navratilova said, but must move forward and take balls earlier. “She hits a big shot to the corner, but is still six feet behind the baseline,” Navratilova said. “She needs to step in and take advantage.”Shriver said players like Maria Sharapova improved their speed and quickness through training. Anisimova is on board: “I’m most focused on my movement and becoming a better athlete, and I think it’s improved a lot over the last couple of months.” Marketa Vondrousova of the Czech Republic at a tournament in Prague last year.Petr David Josek/Associated PressMarketa VondrousovaFor Vondrousova, 22, and ranked 35th, it’s about mental growth more than specific shots. “She’s very talented and has great variety in her shots, but sometimes she gets down on herself mentally,” Stubbs said.Her lack of fire could just be natural reserve, Shriver said, but to prove doubters wrong, Vondrousova must display a killer instinct in rallies: “She has a good lefty forehand, but needs to make it an intimidating weapon.”Clara Tauson of Denmark at the Australian Open at Melbourne Park in January.Mark Metcalfe/Getty ImagesClara Tauson“She has the world at her feet, but needs to get her fitness level up there,” said Stubbs, who expects big things as Tauson, 19, becomes more comfortable on the tour: “If she can get quicker, she won’t have to always hit the big shot.”Shriver said Tauson, who is ranked 43rd, had game-changing power but sometimes lacked intensity: “Maybe she’s just shy, but sometimes it feels like she’s not fully engaged. I’d like to see some passion on the court.”Marta Kostyuk of Ukraine at the Madrid Open earlier this month.Manu Fernandez/Associated PressMarta KostyukWith her father still in Ukraine, this Kyiv native has bigger things on her mind. “Most important is that she gets help dealing with this trauma, because it’s going to be in her life,” Shriver said, adding that Kostyuk, 19, must be patient with her tennis game for now.Kostyuk, who is ranked 58th, said that in addition to working on her shot selection during rallies, she was most focused on “staying in the present.”However, even without the horrors in her homeland, that is not easy to work on in practice. “It is a big part of it,” Kostyuk said, “but these are abstract ideas, so it’s not like just working on your down-the-line backhand.” More