This article is part of the Winning Style series, a collection of articles that explore the methods elite tennis players adopt in order to remain at the pinnacle of the sport. NEW YORK — With the meticulously designed, multi-layered outfits she wears at Grand Slam tournaments, four-time major champion Naomi Osaka adds to a rich history of tennis players who have used fashion to push against the tightly bound seams of the sport.No one in tennis causes as much cultural conversation as Osaka. But at this U.S. Open, she has some competition welling from an unlikely source — men.The leading man? Carlos Alcaraz, the tournament’s genial defending champion who turns tennis matches into carnivals. He has spent his spring and summer rehabbing an injured wrist and experimenting with his street style in the meantime. That increased interest in fashion has spilled onto the tennis court in New York, where Alcaraz walked out for his first match in a brown-and-white ombre tank top, the product of a collaboration between Cactus Jack, the rapper Travis Scott’s brand, and Alcaraz’s clothing sponsor, Nike.The top’s jersey-like fabric is in line with Nike’s basketball-inspired collection for this tournament; its chocolatey palate and reverse swoosh are custom touches. But what prompted conversation was the cut of the top, which is less like the muscle tanks Alcaraz usually wears and closer to a wrestling singlet.Alcaraz would hit a groundstroke, or a serve, or run for a ball, or do anything, and the tank would shift, revealing a nipple.Viewers noticed. Alcaraz noticed.U.S. Open round one: What did we learn?Ava Wallace and Johnny SweetBy the second round, he appeared to be checking to make sure his shirt was in place before games.By the third round, he’d popped on a white base layer underneath and uttered a sentence that, though it’s impossible to check, has probably never been said before in a tennis news conference.“Well, I think I saw my nipple too much lately,” Alcaraz said Friday, laughing.“I felt like, you know, I could hide it for at least one match.”Want to measure how far tennis has come from the days of starched polos and pleat-front shorts? Look to Alcaraz, who with his generously cut tank top — and good humor about the situation — is bringing on-court personality that is still gold dust in men’s tennis, in a style of top that its modern exponents say they wear for performance, as much as style.The cut of Carlos Alcaraz’s U.S. Open outfit led him to make some wardrobe changes. (Timothy A. Clary / AFP via Getty Images)Tank tops in men’s tennis are nothing new. Alcaraz almost always goes sleeveless at the U.S. Open, and Frances Tiafoe and Ben Shelton commonly wear tanks. Taylor Fritz and Alexander Zverev have also sported a fair few. Conjure up an image of Rafael Nadal on a tennis court, and he’s probably wearing a muscle tank, long shorts and a tie-back headband.Tank tops in men’s tennis are also not that old.It was just 24 years ago, at the 2002 U.S. Open, that German No. 3 seed Tommy Haas dared to go sleeveless for the first time in the sport’s history — in a Nike tank.He made it about one minute into his warm-up on Louis Armstrong Stadium before Brian Early, the tournament referee, told him to change.Anything leaving biceps exposed was not what Early considered acceptable tennis attire. Unlike Serena Williams’ Puma catsuit, which the 23-time major champion wore at the same tournament, Haas’ outfit had not been approved in advance.There was no rule against sleeveless tanks. The sport’s unwritten code won out.“It wasn’t, like, a basketball tank top,” Mike Nakajima, who at the time was the director of Nike’s tennis marketing efforts, said during a phone interview.“It was just a sleeveless shirt. And Brian says, ‘Nak, it’s not a traditional tennis outfit.’ I was not happy. You wanted to get butts in seats? Well, this would have done it.”While playful experimentation with style has been ingrained in the women’s game since the days of Suzanne Lenglen, fashion mavericks are scarce on the men’s side. Andre Agassi rebelled with his mullet and denim shorts, and Roger Federer found room within his polished persona to flaunt his individual style, which always served to underscore his legendary status. (Think of his monogrammed white blazer at Wimbledon.)Rafael Nadal was synonymous with the tank top early in his career. (Erik Feferberg / AFP via Getty Images)This U.S. Open isn’t the first time Nike has brought together basketball and tennis courts — Federer sported the Virgil Abloh-designed Jordan 1 sneakers with “Air Federer” scrawled on the sides in 2017 in a collaboration that put two iconic athletes side by side.But generally, men’s tennis dress has always been more uptight compared to the creativity of the women’s game.“When I first started on tour, we had to wear collared shirts,” James Blake, the former world No. 4 who now serves as an ESPN commentator, said during an interview. “Listen, the dry-fit T-shirt with a round neck was considered progress back then.”The ATP approved the tank top for a six-month provisional period starting in 2003, and Nike, which moved quickest to adopt it in its men’s collection, then sent an outfit for approval to each of the Grand Slams. Wimbledon was the first major to say yes, despite its stuffy reputation. The other majors followed, and Blake debuted the top at the Australian Open. Since then, other brands have joined the tank-top party, including Lululemon, On and Adidas, but Nike is most synonymous not only for the outfit but for having players willing to carry it off.Blake and the Spanish former No. 1 Carlos Moya were Nike’s first choices to be the spokesmen for sleeveless, though Blake took some convincing come Wimbledon. His mother is British and Blake didn’t want to dishonor the sport’s most traditional tournament. Moya, meantime, was worried about a tattoo on his arm showing.“He was a little nervous because there was a stigma,” Blake said.Blake truly fell for them when he realized how much more convenient they were for his lifestyle. He no longer had to pack double the shirts on long road trips because his match-day clothing was comfortable enough for practice.But it was Nadal who made the tank top his signature armor as his star rose. The Spaniard gave Nike the perfect blend of physique and aura to carry the look.“It was sort of like the bull right?” said Chanda Rubin, who was on the WTA Tour at the time of the tank-top revolution and now commentates for Tennis Channel.“It was synonymous with his image. His game was hardcore, in your face, we’re going to stay out here all day, go toe-to-toe.“That shirt reads differently on an elegant player. The tank top was all part of the visual. That’s why he became so iconic with it.”Still, even Nadal only spent roughly 2005 to 2008 sleeveless, with some intermittent reappearances in hot and humid conditions.Sportswear brands still choose carefully when it comes to who gets to bear arms, and not all players want to go that route. Alcaraz, with his eye-popping shotmaking, buoyant personality and ever-changing hairstyle, is Nike’s tank-top wearer, not Jannik Sinner, who mostly sticks to polos.For Frances Tiafoe and other tank-top wearers, the benefits are practical as much as sartorial. (Dylan Buell / Getty Images)Tiafoe, Shelton and British star Jack Draper have been deemed to have big enough muscles, personalities and games by their respective clothing sponsors Lululemon, On and Vuori. There aren’t too many other men on tour who commonly wear them.But for those who do, most of the benefits appear practical. Tiafoe and Shelton are delighted with their comfort: Shelton doesn’t like any extra weight on his arms, or how sweat drips down to his hand when he wears sleeves.For Tiafoe, shoulder mobility is a key advantage.“Playing in a tank, you are freer, there’s no question about it, without a sleeve, yeah. Obviously it’s lighter just naturally just in a tank,” Tiafoe said in a news conference.“Tank tops are the best. I mean, I love playing in tanks. It’s just so fun. Obviously I love basketball. It’s just a vibe.”Making tennis a little less upper crust and a little more vibey is the point of putting a player in a tank top, said Sunita Kumar Nair, fashion creative director and author of the recent book “ACE: The Times & Style of Tennis.”“I’m excited for tennis stripping away this elitism, coming on the same ground and being in that conversation,” Nair said.“With Alcaraz, it’s the same thing I see when he tries out different hairstyles. He’s a 20-something-year-old wanting to express himself, expressing the personality he isn’t always able to express within the confines of tennis.”While the prevalence of tank tops is one measure of the sport’s evolution from country club pastime to pop culture institution, Nakajima said tradition isn’t the only reason sleeveless shirts are still rare in men’s tennis.The bottom line still rules for apparel brands. While tank tops are no longer taboo, they don’t sell well with the average consumer.“I would say 80 percent of tennis outfits never make it on the court. It’s a polo that you want to wear with jeans,” Nakajima said.“But now that things are so design-driven. … Some people will buy Carlos’ outfit because it’s been crossed with basketball. But the traditional tennis consumer, it’s not the kids. It’s older people. They’re like, you don’t want to see my arms on court.”That is the one thing Alcaraz shares with the average tennis player: the desire to cover up.The Winning Style series is sponsored by Ralph Lauren.The Athletic maintains full editorial independence. Sponsors have no control over or input into the reporting or editing process and do not review stories before publication.