Notice anything different about Jannik Sinner’s serve lately?
The Italian introduced a new serve mid-season and he hasn’t looked back, with incredible serving numbers captured by TDI Insights data.
His serve set the stage for his first two wins at the Nitto ATP Finals, scoring 89% of his first-serve points in a 6-4, 6-4 victory over Stefanos Tsitsipas, and then against May. He scored 79 percent of his first serve points against the game’s greatest ever returner, Novak Djokovic, in three thrilling sets.
“He restructured his serve with Darren. [Cahill] It’s a very, very difficult thing to do,” former world No. 4 Greg Ruseski told ATPTour.com this week.
“I’m very impressed; the whole team did a great job with him. It all started with changing the serve, the body, the transitions, adding slices and adding things. They’re still not 100 percent natural, but over time they just It’s going to get better because he’s one of those guys who’s willing to put in the work.”
The chart below shows the changes in Sinner’s movement in the second half of the year.
Sinner made significant adjustments to his stance and preparation technique. For the first half of the year, he adopted a back-foot or platform stance, keeping his back foot in the starting position until takeoff. However, he has now transitioned to a feet-up or pinpoint stance. In this stance, the initial foot position is usually wider, and then the back foot moves up with the front foot before the player leaves the ground.
In addition to the change in stance, Sinner also modified his preparation technique. Previously, there was an exaggerated separation between his ball launch and racket arm, with his right arm falling further behind the ball launch path created by the racket hand, giving it a spiral-like appearance. However, Sinner now resorts to a more classic offside lift. This technology involves a smoother and more circular motion of the racquet, in front of the shoulder line, thereby reducing the delay between ball placement and racquet lift.
ATPTour.com Brain Game Analyst Craig O’Shannessy said: “Watching his first two games at the Nitto ATP Finals, you can see that he simplified his movements. So, at the beginning, he got into a ready position and then It’s basically just going down. So there’s not a lot going on and there’s not a lot that needs to happen.
“He’s particularly good on the AD pitch. That’s where he won a lot of points against Novak in crunch time. So he has height now, but also simplicity. He’s going back and forth between lifting his foot and retracting his foot. But now that he’s found the right rhythm, I think that’s the serving motion that should stick.”
TDI Insights data reveals the importance of service change. On his first serve, his shot quality soared from 7.8 to 8.2, and his serving efficiency climbed from 61.6% to 64.9% (picture below). Insights data also shows that his contact height with the ball is higher (2.88m vs. 2.85m).
The data also showed that Sinner went for bigger serves on break points, which resulted in him saving 75% of break points, compared to 66% before the change. Perhaps most importantly, his service winning percentage increased from 84% to 89%.
Ruseski said Sinner’s rock-solid serve has now become the foundation of his wider success and he will climb even higher next season.
“He’s gotten himself in better shape because he’s gotten a little leaner. He’s willing to take a cut once in a while and transition forward. It’s just a mentality,” Ruseski said. “There are no real weaknesses on either side. I think the more easily he can use the firepower in the backcourt moving forward, his shot selection will improve.
“I think you have him right now as one of the guys you think is next to win a Grand Slam. If you pick a player in 2024 that you think has a real chance of making a final or winning a Grand Slam, his name is right now. Number one on the list.”
But 2024 will have to wait a little longer. Sinner is focused on using her serve in her bid to win the Nitto ATP Finals crown.
Learn more about TDI Insights data