Have you noticed anything different about Jannik Sinner’s serve lately?
The Italian introduced a new serving move mid-season and hasn’t looked back, putting up incredible serving numbers captured by TDI Insights data.
His serve has been the basis of his first two victories at the Nitto ATP Finals, where he won 89% of the points on his first serve in a 6-4, 6-4 victory over Stefanos Tsitsipas, and then 79% of the first serves against the best returner in history, Novak Djokovic, in an exciting three-set match.
“The serve has improved with Darren [Cahill] and that’s a very, very difficult thing to do,” former world No. 4 Greg Rusedski told ATPTour.com this week.
“I’ve been super impressed; the whole team has done a fantastic job with him. And it all started with a change in the serve, the body, the transition, adding slices and adding things. They’re still not 100% natural, but they’re just going to get better over time, because he’s one of those guys who’s going to put in the work.
The graph below illustrates the change in Sinner’s movement in the second half of the year.
Sinner has made significant adjustments to his stance and preparation technique. In the first half of the year, he used a backfoot or platform stance, in which the back foot remained in its starting position until takeoff. However, he has now changed to a raised foot stance. In this stance, the initial foot placement is usually wider, and then the back foot moves up along with the front foot before the player leaves the ground.
In addition to the change in stance, Sinner also modified his preparation technique. Previously, he had an exaggerated dissociation between ball placement and racquet arm, in which his right arm would fall further behind the ball placement path created by the racquet hand, giving the appearance of a spiral. However, Sinner has now adopted a more classic topspin. This technique involves a smoother, more circular movement of the racket, positioned in front of the shoulder line, which reduces the delay between placing the ball and raising the racket.
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Craig O’Shannessy, ATPTour.com Brain Game analyst, says: “After watching his first two matches at the Nitto ATP Finals, you can see that he has simplified the move. At first, he gets into a ready position and basically drops. So there’s not a lot of wind. You don’t have to do a lot of things.”
“He’s serving particularly well on the lead. That’s where he won a lot of points against Novak in the big moments. Now he’s got height and simplicity. He’s been going back and forth between lifting his foot and keeping it back. But now he’s found the right rhythm. and I believe that this is the movement of service that should follow.
TDI Insights data reveals just how significant the service changes have been. On the first serve, the quality of his shot has risen from 7.8 to 8.2 and the effectiveness of the serve has increased from 61.6% to 64.9% (graph below). The Insights data also shows that he is making contact with the ball at a higher altitude (2.88m vs. 2.85m).
The data also reveals that Sinner makes bigger serves when on break point, allowing him to save 75% of break points compared to 66% before the change. And, perhaps most importantly, he is winning 89% of service games, up from 84% previously.
Now that his strong serve is the foundation of his greatest success, Rusedski says Sinner is primed to reach even higher next season.
“He’s in better shape because he’s lost a little bit of weight. He’s willing to add a little slice every now and then, a forward transition. It’s just a mentality,” Rusedski said. “There’s no real weakness on either side. And I think the more comfortable he gets with transitioning forward with the firepower that he has from the back the more his shot selection has improved.”
“I think he is now one of the players who is called to win a Slam. If you take a player who in 2024 you think has a real chance of reaching a final or winning it, his name is number one on the list right now” .
But 2024 will have to wait a little longer. Sinner is focused on taking advantage of his serve to push towards winning the Nitto ATP Finals crown.
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