The raw numbers tell plenty about the effectiveness of Jannik Sinner’s serve at the Australian Open, but sometimes it takes a vanquished opponent to best explain just why it’s become one of the Italian’s weapons of choice.

World No.1 Novak Djokovic’s six-year unbeaten streak at Melbourne Park had just ended at Sinner’s hands in dramatic centre court scenes late in the day session at Melbourne Park on Friday. Extraordinarily, the Italian world No.4 didn’t even offer up a single break point to Djokovic, undoubtedly one of the game’s best returners.

World No.4 Jannik Sinner.Credit: Getty Images

Djokovic was succinct when asked how Sinner, a player he’s now lost to in three of their past four clashes since November, had improved. The deceptively powerful Sinner earned praise for “smacking the ball really hard from both forehand and backhand corner”, but his serve, thanks to some subtle technical changes, didn’t escape mention.

“I think his serve improved a lot,” said 10-time Australian Open champion Djokovic. “He’s hitting his corners very well, and I think he [has upped] speed, as well.

“[He’s] serving bigger now and [it’s] more precise.”

Sinner has dropped serve just twice in six matches at Melbourne Park so far this tournament. He’s only lost one set, too – the third set on Friday when Djokovic did everything to stop the inevitable and forced a tie-breaker. The Italian’s only other tie-breaker came against Andrey Rublev in the quarters.

His tournament numbers tell a simple story. The percentage of service games won (98 per cent) is strikingly top of the tops among the men. Of those men’s singles players who went deep in the tournament, only Poland’s Hubert Hurkacz (91 per cent) and Rublev (also 91 per cent) are within range.

Sinner hasn’t had the highest first-serve percentage (60) but he’s ultra-effective when on-target, recording a return of 78 per cent on first serve points won. That’s not far behind the effectiveness of the big-serving Hurkacz (83 per cent).