Here's Why Sinner Has Become A Super Server...

Noticed anything different about Jannik Sinner's serve lately?

The Italian introduced a new service motion midway through the season and he hasn't looked back, running up incredible service numbers captured by TDI Insights data.

His serve has underpinned his first two victories at the Nitto ATP Finals, where he won 89 per cent of points on his first serve in a 6-4, 6-4 win over Stefanos Tsitsipas, and then 79 per cent of first serves against arguably the game's greatest-ever returner, Novak Djokovic, in a three-set thriller.

“He retooled the serve with Darren [Cahill] and that's something very, very difficult 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 making a change to the serve, the body, transitioning, adding slice and adding things. They're still not 100 per cent natural, but they're only going to get better with time because he's one of those guys who is going to put in the work."

The graphic below illustrates the change in Sinner’s motion 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 foot-back or platform stance, where the back foot remained in its starting position until take-off. However, he has now transitioned to a foot-up or pinpoint stance. In this stance, the initial foot placement is typically wider, and then the back foot moves up alongside the front foot before the player drives off the ground.

In addition to the stance change, Sinner also modified his preparation technique. Previously, he had an exaggerated dissociation of ball placement and racquet arm, where his right arm would lag further behind the ball placement path created by the racquet hand, giving the look of a spiral. However, Sinner has now adopted a more classical off-side lift. This technique involves a smoother and more circular motion of the racquet, positioned in front of the shoulder line, resulting in reduced delay between ball placement and racquet lift.

ATPTour.com Brain Game analysist Craig O’Shannessy says, "Having watched his first two matches at the Nitto ATP Finals, you can see that he's simplified the motion. So at the start, he gets into his ready position and basically just drops. So there's not a lot of wind up. There's not a lot of things that need to happen.

“He’s serving particularly well out wide in the Ad court. So that was where he won a bunch of points against Novak in big moments . So he's got the height and he’s got the simplicity now. He's gone back and forth between bringing his foot up and keeping it back. But now he's found the right rhythm and I think this is the service motion to stick with.”

TDI Insights data reveal just how important the service changes have been. On first serve, his shot quality has surged from 7.8 to 8.2 and serve effectiveness has climbed from 61.6 per cent to 64.9 per cent (graphic below). The Insights data also show that he is making contact with the ball at a greater height (2.88m vs. 2.85m).

The data also reveal that Sinner is going for bigger serves when down break point, which has resulted in him saving 75 per cent of break points versus 66 per cent before the change. And, perhaps most important, he is winning 89 per cent of service games, up from 84 per cent.

With his rock-solid serve now the foundation of his broader success, Rusedski says that Sinner is set to climb even higher next season.

“He got himself in better shape because he's gotten a little bit leaner. He's willing to add in a slice once in a while, transition forward. It's just a mindset," Rusedski said. "There's no real weakness on each side. And I think the more comfortable he gets with transitioning forward with the firepower he has from the back that his shot selection has improved.

"I think you put him in the mix now as one of the guys who you think is next to win a Slam. If you take one player who in 2024, you think has got a real shot to make a final or win one, his name is number one on the list right now."

But 2024 must wait just a little longer. Sinner's is laser focused on leveraging his serve to push towards capturing the Nitto ATP Finals crown.

Learn more about TDI Insights data