Why Jannik Sinner’s forehand is unique — and so dangerous on the tennis court

NEW YORK — In the history of tennis, a small number of players have possessed the ability to make a crowd gasp. From the sheer venom of an Andre Agassi return to the beauty of a Roger Federer half-volley and the crack of a Juan Martin del Potro forehand, a chosen few have had the gift.

And then there is the sound of a Jannik Sinner forehand.

The Italian’s groundstrokes are the bedrock of his game, the power and speed of his shots keeping his opponents under pressure throughout. They were a key factor in earning him his first Grand Slam title, at the Australian Open in January, and have been integral to his rise to the world No. 1 ranking.

Sinner came into the US Open last week surrounded by the recent news that he had tested positive twice in March for traces of a banned steroid. He escaped a ban when anti-doping authorities accepted that he had been accidentally cross-contaminated via a spray used by his physiotherapist to heal a cut on his finger.

Despite the controversy, Sinner has looked all but unstoppable, getting through his matches at Flushing Meadows with relative ease. With Carlos Alcaraz and Novak Djokovic gone early, he is the favorite for the title, and will face Daniil Medvedev in the quarterfinals on Wednesday. Through it all, he has relied on that unique forehand.

And it’s not just the speed, power, accuracy or technique. It’s also the sound, especially on his forehand, his long levers and high racket-head speed allowing him to whip the ball through the court with a crack. It was the first thing that Darren Cahill, who joined Sinner’s coaching team in the summer of 2022, noticed.

“The sound of the ball when he hits it, it’s pretty amazing, isn’t it?” Cahill told reporters in Melbourne earlier this year.

“Agassi hits the ball like that. When he hits the ball, it just sounds like it’s hit harder than everybody else. Rafa [Nadal] was exactly the same. Roger [Federer], when he hit a forehand, you could just hear the sound of it. And Novak [Djokovic], when he hits a forehand and backhand, it’s like a thud. It’s not just a normal person striking the ball. All those players have a different sound when they hit the ball and Jannik certainly has that as well.”

According to TennisViz, a company that analyzes the ATP Tour, the speed of Sinner’s forehand has remained remarkably similar ever…