The US Open will always be special to Carlos Alcaraz. It was the site where the Spaniard won his first-ever Grand Slam title and ascended to World No. 1 as a teenager. Three years later, as he leaves the 2025 edition following a sublime four-set victory over his rival, Jannik Sinner, in the final on Sunday, the result is the same: he won his sixth Major trophy and returned to the top spot of the rankings. But it felt like looking at an entirely different player, right from his buzzed-off hair and chiselled physique to his steely-eyed focus and ruthless attitude. At the top tiers of tennis, even the supremely talented need constant improvement; Alcaraz is leaving New York with the trophy that is testament to that. And talent is an area where nobody has ever doubted the 22-year-old whose all-court game has all the shots in the book and can seamlessly blend power and deftness. Rafael Nadal recently said that he is capable of producing magic in a way that nobody else can. But at what cost? "From my point of view, Carlos can improve a little bit the tactical way to approach some matches. Sometimes it feels like he always plays for every big shot, and sometimes, he doesn’t need that much," Nadal said in an interview with The Athletic. His pursuit of producing the spectacular at every point had led to a perceived fragility. A few unexpected early defeats and long hours spent on court to win routine matches didn't help; especially when Sinner mercilessly established a dominant hold over the rest of the tour. Yet, when he arrived in America this year, something changed. During that breakthrough triumph in 2022, he had spent just under 24 hours on court. This year, it was just under 12. He dropped seven sets that year, and just one, in the final, in this tournament. Nothing represents the stark improvement, in both technique and temperament, like Alcaraz's serve. His team had tried to drill into him that it remains the one area where major improvements were required. They had painstakingly reworked it in full public view throughout this year, and it finally reaped dividends. He was broken just thrice all tournament in 2025: only Pete Sampras (who was broken only twice in Wimbledon 1997) had ever dropped fewer service games in a Major-winning campaign. Three years ago, that number was as high as 24. This time he won 98 of 101 service games. And this development isn't gradual; the erratic nature of his game was on display as recently as Wimbledon in July, where he needed five tetchy sets just to win the first round. So where has it come from? "He’s growing up,” Juan Carlos Ferrero, Alcaraz's coach since childhood and a former World No. 1, said at a news conference after the final. "We are very clear what he has to improve on court and off the court, and I think he’s mature (enough) to believe that." Nothing could mature him like a tough defeat. Alcaraz arrived in London after a successful summer and having defeated his only real competitor for a sixth consecutive time by saving two championship points in the French Open final. But Sinner drubbed him in four sets in the Wimbledon final, stealing his grass crown and also establishing himself as the out-and-out standard-setter in men's tennis with a huge lead in the rankings and three of the four previous Majors. Unacceptable. Alcaraz came to New York locked in and did not give anybody an inch. It wasn't just the serve, but an all-round ruthlessness: he unloaded his huge forehand and unfurled the signature deceptive drop shots with more restraint, less frequently but more effectively. He reduced errors, finding joy in point construction as much as point-winning. Sinner acknowledged how much better his rival had got. "The things that I did well in London, he did better today. I felt like he was doing everything slightly better today, especially serving, both sides, both swings very clean… He raised his level when he had to," the Italian said after the final. After equally splitting each of the last eight Majors, this is being touted as the next big rivalry. There is a lot of talk. But if they are to produce those highs, they will have to push each other to improve. Sinner acknowledged that, too. "I was very predictable today. On court, in the way he did many things, he changed up the game. Now it's going to be on me if I want to make changes or not. Definitely, we are going to work on that," he said. The message? Hat-tipped, see you at the next one.