Jannik Sinner is serving his way through Wimbledon as familiar foes lie in wait – The Athletic

THE ALL ENGLAND CLUB, London — Just in time for the most intense part of Wimbledon, London is heating up.

Jannik Sinner, the defending men’s champion and world No. 1 who has shown a propensity to melt in hot weather, is likely to play a familiar foe in the semifinals: 24-time Grand Slam champion Novak Djokovic could be waiting for Sinner, 24, under a bright, 87-degree sun on Friday afternoon.

Ahead of the tournament, Italy’s Sinner said he and his team have committed to more hot-weather training, to acclimate his body to a schedule that feels it grows hotter every year.

But at this edition of Wimbledon, Sinner’s issues have so far been more prosaic, and the fix easier to find. His baseline game is out of rhythm. His serve is the vicious metronome keeping him on the straight and narrow.

Once again, against the dangerous Jan-Lennard Struff of Germany, who mixes a thunderous serve of his own with a propensity to move forward and attack at will, the Italian’s delivery was key to victory.

Across a 7-5, 7-6(4), 6-3 win, Sinner hit 16 aces to Struff’s 12. He landed 65 percent of his first serves and won 84 percent of those points, and crucially, he still won them when Struff did get the ball back. Sinner won 69 percent of his first-serve points that Struff got over the net and between the lines; when Sinner made a first-serve return, he won the point more than he lost it.

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Sinner had called out his serve after his fourth-round win over Shintaro Mochizuki, the world No. 151 from Japan. Sinner won the first set comfortably in 33 minutes, but the match appeared to tighten in the second set, when it headed into a tiebreak. If Mochizuki was going to have a chance to get his teeth into the match, this was it.

Really, Mochizuki never had a chance, even if on the surface it looked like Sinner might be in for another long day, after having gone five sets against Serbia’s Miomir Kecmanović in the first round.

In the second set against Mochizuki, Sinner landed over 70 percent of his first serves, and he won 24 of 28 points when he did. He smacked 10 aces. Overall, he played 38 points on his serve, and on 17 of them, he didn’t have to hit a second shot.

He served on just three of the seven points in the tiebreak, which he won 7-0. An Ace. A kicker onto the T that had Mochizuki on the back foot, then a slice out wide that Mochizuki dumped into the net.

“I felt like I was serving well at times, especially important moments today,” Sinner said in his news conference. “That helped me also being a bit more freer in the return games.”

Therein lies the Sinner blueprint for the rest of the Wimbledon fortnight, if he is going to lift the trophy for a second consecutive year. He is not the player he was in the early clay-court season, when he won three consecutive tournaments —  the Monte Carlo Masters, the Madrid Open and the Italian Open. He won the BNP Paribas Open at Indian Wells and the Miami Open before them, but even in that dominant hard-court run, there were signs of slippage.

Then, Sinner used his serve dominance to offset shakiness in his baseline game, especially on his forehand. Nothing got worse in a meaningful sense, but in tennis, a sport of such fine margins, tiny changes in win rate — especially on the most common kinds of points — can have a big impact.

In early 2026, his serving earned him a one percent increase on his average win rate on points that last between zero and four shots. That doesn’t sound a lot. But that’s the most common point in tennis, and as Sinner’s win rate on points over nine shots slipped four percent below average, the one percent shift did enough offsetting for him to keep winning.

The most devastating version of Sinner, who mauls opponents from the back of the court, showcases masterful touch when he comes forward and still serves like a metronome, may yet appear.

After melting and cramping in the third round of the French Open against Juan Manuel Cerúndolo, the world No. 54 at the time, Sinner took a well-deserved rest. He didn’t play a competitive match until Wimbledon, where he was understandably rusty against Kecmanović.

This is an era when having a killer serve to use as a pressure-release valve has never been a more valuable weapon in both the men’s and women’s game. Players are so athletic, and so many points can flip from offense, to defense and back again, that as long as the rest of a player’s game is solid, an effective serve can become something of a fortress.

It’s especially true on grass, where a ball skids and slides and slices off the court instead of popping up like it does on clay and some hard courts. Four-time major champion Naomi Osaka, who has long struggled on grass, has made opponents feel like they can’t breathe during the first week as she has set the pace for serving in the women’s tournament, nailing corners with her 120 mph bombs.

Sinner is frustrating opponents who feel powerless to make any headway, no matter how close the score might look at any given point in a match and no matter how much they might feel that they can hurt him from the baseline.

“He served well, so I couldn’t break any games,” Mochizuki said after his three-set loss to Sinner. “That cost me a lot.”

This has been coming for a while for Sinner. Beginning when he made the switch in 2022 from a platform stance (feet apart) to a pinpoint stance (feet together) before the jump in his motion, Sinner’s serve has become far more than simply a point-starter. That allowed him to jump a couple inches higher and hit down on the ball more.

It was largely responsible for taking down Novak Djokovic in four sets in 2024 at the Australian Open, when the best male returner of the modern era not named Andre Agassi could not manage a break point in a five-set match for the first time in his career.

Jannik Sinner’s serving has carried him through difficult moments. (Cameron Spencer / Getty Images)

More than two years later, Sinner’s serve has had its moments of dysfunction. He struggled with it at the U.S. Open last summer, especially in the final, when he landed just 48 percent of his first serves and Carlos Alcaraz duly blew him off the court.

This Wimbledon has been the opposite of that. He has smacked 81 aces in four matches. That’s the equivalent of five “free” games each match.

His first-serve percentage is a reliable 66 percent, and he’s winning 85 percent of those points. More than half of his successful first serves are going unreturned.

A scattergraph of his opponents’ contact points when they are returning his serve shows a frightening number of dots outside or on the edge of the tramlines. Sinner isn’t much for serving into an opponent’s body. Just a handful of balls land in the middle third of the service box.

All of this means no one can get their hopes up too high when the serve does get returned. Sinner is winning 69 percent of those points, the best in the field.

The question now is whether that will be enough to neutralize what might be Sinner’s most potent foe this week — the weather. He brushed away a question about the forecast after his win over Mochizuki, claiming he knew little about the coming heat, just as much as he pushed back against the idea that the weather had felled him in Paris right after it happened.

In London two weeks ago, he reversed course and allowed that he had a problem that needed fixing. Against Struff, he didn’t need to fix it, because his serve again carried the day.

“We did a good preparation,” he said. “Whatever happened in the past, it’s gone already. Now we see if we found a solution. If not, we keep working for the next one.”

He knows how the pressure ratchets up in the final round of a Grand Slam. He said he’s ready for it this time.

“There is definitely more tension. In the same time, I’m very happy where I am at the moment,” he said.