The former American ATP player who Jannik Sinner has ‘copied’ and based his serve technique on

The 23-year-old now has three majors to his name and has been the top-ranked ATP player for over a year.

This is due to the improvement in Sinner’s all-around game, especially where his serve is concerned.

Jannik Sinner’s coach Darren Cahill says they based his serve on John Isner’s

There are several aspects of Sinner’s game to be impressed by, such as his consistent ball-striking, aggression and athleticism on court.

But arguably the most improved shot in the Italian’s repertoire is his serve, which is now a dangerous weapon on court.

During an appearance on Andy Roddick’s ‘Served’ podcast, Sinner’s coach Darren Cahill names the former ATP player that he wanted the World number one to model his serve after.

“We said it was a three step plan with his serve because his serve was very side on and there was no shoulder rotation at all, so he started with the action with the shoulders and then we moved it to the step up,” he said.

“‘The reason why we went to the step up right before Wimbledon was in one year is he took that bad loss, he thought it was a bad loss, it was Daniel Altmaier played incredibly well at Roland Garros in the second round.

“But he was pretty disappointed with the way he served and the way he played and he asked. He said, where are these improvements going to come from?

“Then we sat down, the next thing that we need to do is the progress your serve, and we both believe you’re better to step up. We were going to do this at the end of the year. ‘This is going to be the next progression with your serve.

“He goes ‘we’re going to do it now’. So within a day, we went to the courts and Roland Garros. He goes, right, ‘what do I need to do?’ We copied John Isner a little bit at the start. Not a bad serve to copy.’

What has John Isner said about Jannik Sinner’s serve?

During sections of the 2024 season Sinner led the ATP Tour in service games won (91.3%), second-serve points won (57.5%) and break points saved (72.9%).

Sinner currently wins 77% of his first serve points and an impressive 61% of points behind his second serve.

In September 2024, Isner noticed Sinner’s improvement on serve and said: “A lot of people have noticed, myself included, that Sinner has, really since working with Darren Cahill, changed his service motion from platform to pinpoint.

“His serve looks pretty similar to mine and in my mind, that’s the superior way to serve. So he obviously stuck with it. It seems like it would be a simple change, but it’s definitely not.

“He stuck with it, stayed the course and it’s paying off for him as his service numbers are so, so good.”