Every great tennis player has a weakness, especially in their early years.
Roger Federer’s single-handed backhand, a work of art, was vulnerable when the ball bounced high. Rafael Nadal exploited that so relentlessly that Federer remodeled the shot and started using a larger racket to stop the bleeding.
Nadal and the third member of the Big Three, Novak Djokovic, arrived on tour with mediocre serves and imperfect physiques. Nadal’s knees and feet caused him to miss chunks of so many seasons. Djokovic struggled with his fitness and had a reputation for pulling out of matches with various ailments. Then he turned his serve into one of the most efficient in the sport. They won a few Grand Slam titles, those three — just the 66 and counting, with Djokovic still on the scene.
And so it is with Carlos Alcaraz, who has more magic in his right arm than anyone in the men’s game — except when he steps up to the baseline, ball in hand. His tennis is so explosive, fluent and unpredictable when a rally starts that it can go unnoticed when he ends up playing more of them than he should behind his own serve.
Alcaraz and his team know this better than anyone, which is why the Spaniard, 22, came to this year’s Australian Open with a new, more rhythmic service motion. It’s a work in progress that he hopes will pay dividends in the long run. And things look promising in the short run, too.
Alcaraz won his first event of this season’s clay-court swing in Monte Carlo, Monaco, and made the final of his second in Barcelona. A hip flexor issue during the championship match with Holger Rune helped prevent him from winning a second straight title. But after a bumpy start to the year, in which he has mixed titles with surprising losses full of elementary mistakes, his success on the clay is not surprising.
The slower surface neutralizes players who rely on power serves. That enables a player such as Alcaraz to attack his opponents when they are serving, because he can outplay them once points develop. It also enables him to make up for the games he might lose on his own serve. On faster courts, the deficit is harder to bridge.
“The serve is not as important probably as on hard court,” he said in a post-match news conference in Monte Carlo. “That’s pretty good for me. We are playing, you know, almost every point, so we can’t make a lot of points or free points with the serve.”
Still, he’d prefer to have to do that as little as possible. Winning under pressure is nice, but winning efficiently is often nicer. Soon enough, Alcaraz will be back on grass and hard courts, where the serve can be so decisive. He will also have to face Jannik Sinner, the world No. 1 and his biggest rival at the top of men’s tennis. They produce pyrotechnics when they face each other and Alcaraz leads their head-to-head 6-4, but the widest delta in their abilities is on serve.
Sinner spent much of 2024 remaking his, changing his motion and stance to generate more lift and power. It made a good serve into a truly great one, which skids and slides off the lines and more often than not finds the very corner of the service box.
Alcaraz, the world No. 2 in waiting, has designs on doing the same. But he isn’t there yet, and it’s making his matches more difficult than perhaps they need to be.
“I know that there is going to be a great serve,” he said in a news conference at Indian Wells, Calif. “My second serve, I trust a lot. My second serve I think is a really good and solid one.
“The first serve could be better.”
Ever since he broke into the top level of the professional tour in 2021, Alcaraz’s serve has raised eyebrows. The rest of his game has always been fluid, full of easy power. The serve, though, was a bit awkward — even for a player who sealed his first Grand Slam title, the 2022 U.S. Open, with an ace out wide.
Like a lot of modern players, Alcaraz played with a modified service motion that limited and simplified his movements.
He started with the racket perpendicular to his upper thighs, barely lowering it below his waist. He kept his weight mostly over the center of his body. He paused briefly before rising into what coaches refer to as the “trophy position” with the arms up, ready to snap through the motion.
He won four Grand Slam titles before his 22nd birthday with that serve, but more in spite of it rather than because of it. The exception was the 2024 Wimbledon final, in which Alcaraz produced 135-miles-per-hour-lasers time and again, painting the lines during his rout of Djokovic.
“I’ve never seen him serve that way, to be honest,” Djokovic, who is probably the best returner the men’s game has ever seen, said that day. “Maybe I was missing something this tournament, but I’ve never seen him serve that fast. He must have had a really good serving practice day yesterday.”
Carlos Alcaraz serving at Wimbledon in 2023, when he won his first title on the grass. (Clive Brunskill / Getty Images)
The best of the best never stop trying to improve. Tiger Woods famously reengineered his swing after he won the Masters in 1997 at 21, and then he did it again in 2003, and again in 2010.
Alcaraz, a budding golfer, no doubt knows all about that. He watched Sinner get devastating results — and overtake him as the world No. 1 — after the Italian started rising into his service motion with his feet together (the pinpoint stance) rather than apart (the platform stance). That enabled Sinner to hit the ball at a higher contact point, which gave him more power and margin for error — and three Grand Slam titles to date.
Alcaraz’s changes have been different. He has tried to gain power and accuracy through a more rhythmic delivery.
He now starts his motion by lowering the head of his racket in front of his shins, pointing it down instead of keeping it perpendicular. As he goes through his motion, he loads more weight onto his back foot, which gives him the potential to create more momentum as he comes forward.
He’s ditched the pause, and sends the racket through a full down-and-up motion as he moves into the trophy position. The result is a longer swing path that looks more fluid, like the rest of his brutally graceful game.
In a news conference at Indian Wells, he acknowledged that he is still getting used to the new motion, especially during competition.
“Every day I’m feeling the progress, but sometimes, in the matches, during the practices, you don’t feel as good as you want it, so you have to separate playing from the baseline (from) the serve,” he said.
“If the serve doesn’t work at all, I mean, you can play good tennis from the baseline and forget about the serve.”
Then, as often happens, he couldn’t resist poking some fun at himself.
“I’m close to being a serve bot, I guess,” he said with a grin that conveyed everything.
Alcaraz is many things. He might yet become the greatest men’s player of all time. Four Grand Slams at 21 is a torrid pace.
He is not a serve bot. Not yet, at least.
According to data analysis from Tennis Data Innovations and TennisViz, Alcaraz’s serve is fine. It’s above average but unspectacular, especially compared with the rest of his game. More importantly, it lags behind the best players in the world in what really matters: placement.
Serving fast has become so commonplace in men’s tennis that speed is no longer the defining factor in the sport. What was an elite service speed just 30 years ago, when Pete Sampras was getting above 120 mph and nobody could do anything about it, has become the average. Players in the 40s, 50s and 60s in the rankings are clocking 13o mph with regularity.
In 2024, when Alcaraz won both the French Open and Wimbledon, his average first serve registered 121 mph on the radar gun, compared with 119 mph for the rest of the ATP Tour. Sinner was just one mile per hour faster on average, but his placement was far more accurate. On average, his serve landed just 53 centimeters from the sidelines, compared with 58 for the tour and 63 for Alcaraz.
That gave Sinner a lot of free points. Opponents failed to return 42 percent of his serves compared with 35 percent for Alcaraz. The tour average is 38 percent. And Alcaraz still isn’t finding the corners as much as his fellow top-10 players. Not by a long chalk.
In the past 52 weeks, Alcaraz has hit 20 percent of his serves in the middle of the service box. For Sinner, it’s 6 percent. For Zverev, 4.5. Taylor Fritz? 1 percent. Jack Draper? 4.5. Alcaraz is the outlier by a mile, against his nearest rivals but also the tour average, which is 8.5 percent.
It should be said that Alcaraz’s body serve is effective, and it has something of a surprise element because players across the tour don’t turn to it as often as he does and so aren’t used to it when it happens. He wins points behind body serves more often than the rest of the tour, but he also wins points more often in general when his serve finds the corners of the box.
Carlos Alcaraz at full tilt on serve during the BNP Paribas Open at Indian Wells, Calif. in March 2025. (Patrick T. Fallon / AFP via Getty Images)
The problem is that his real weakness, the one that sees him lose matches that he shouldn’t, is his susceptibility to dips when he sprays errors all about the court. All players go through this to a varying degree, but it’s easier to survive it when they know that they can win a few easy points with one swing of the racket. If a player’s groundstrokes are going awry and they’re not able to routinely hold serve without having to hit them, then that way danger lies.
But even with a subpar serve, this all might work out just fine for Alcaraz. The reduced potency of his delivery means that he gets into an attacking position on his first shot after the ball comes back less often than Sinner and Zverev.
From there, however, Alcaraz zags where the others zig, inverting one of the fundamentals of tennis probability. The rate at which most players win points when in attack generally drops as a point gets longer, as the upper hand that serving provides fades. Alcaraz, though, gets more efficient as the point goes on. On his third shot, his conversion rate hovers just above 60 percent. By the seventh shot, he’s up to nearly 75 percent.
Needless to say, that is not how a serve bot behaves.
“On clay you can watch the real tennis,” he said in Monte Carlo like a true Spaniard, the country known more than any other for its dirt-ballers.
“On clay you see long rallies,” he said, mentioning a 48-shot exchange between Zverev and Matteo Berrettini. “That’s what I like.”
(Top photo: Marco Bertorello / AFP via Getty Images)