Cahill and Vagnozzi Unravel the Serve Mastery That Secured Sinner’s Nitto ATP Finals Victory
A glance at the coaches’ reactions following the monumental win against Alcaraz
November 17, 2025
Corinne Dubreuil/ATP Tour
Jannik Sinner celebrates his Nitto ATP Finals championship with his team.
By Andy West
Even amidst an extraordinary 2025 season on the ATP Tour, Jannik Sinner’s team was aware that there were always areas for enhancement.
In a dazzling finale on Sunday night in Turin, Sinner triumphed over his fierce competitor Carlos Alcaraz in straight sets, successfully defending his Nitto ATP Finals title. A pivotal element of Sinner’s glorious run at this prestigious event was his serve; afterward, his coaches, Darren Cahill and Simone Vagnozzi, shared insights on the recent modifications made to this critical aspect of the World No. 2’s game.
“Certainly, following the US Open, we identified several areas for improvement, notably with the serve,” Vagnozzi stated at Inalpi Arena after Sinner’s 7-6(4), 7-5 victory. “We altered the serving motion and rhythm, and he served exceptionally well from Shanghai to here. However, in the second set, he experienced a bit of a struggle.”
“I believe Carlos adjusted his positioning on Sinner’s second serve, influencing his rhythm. In that second set, Sinner’s serve tempo slowed down, which disrupted the fast pace he had created in the first. Thankfully, Jannik is incredibly quick to grasp and adapt to changes,” Vagnozzi added.
Sinner had reached the finals of all four majors in 2025 leading up to the adjustments Vagnozzi referenced, capturing championships at both the Australian Open and Wimbledon. Thus, it was somewhat unexpected that his coaches felt changes were necessary. However, Cahill underscored the importance of refining what he termed “the pivotal shot in tennis.”
“In tennis, you have control over just one shot: the serve,” remarked the Australian coach. “Jannik and Simone have put in remarkable work over the past four to five weeks to fine-tune the serve, finding the ideal rhythm and tempo, which allowed him to enhance his first-serve percentage.”
“It’s not solely about increasing the first-serve percentage; if we were just concerned about that, we could have him slow the serve down to land more first serves. Instead, he’s actually increased his speed, hitting closer to the lines, which has resulted in more free points earned. They’ve done an exceptional job with that,” Cahill concluded.
Time for a team photo with a special guest 🐶😅 @janniksin | #NittoATPFinals pic.twitter.com/NAoSRQ5xFA
— ATP Tour (@atptour) November 16, 2025
The results certainly validate Cahill’s perspective. Following his defeat to Alcaraz in New York, Sinner claimed titles at ATP 500 events in Beijing and Vienna, as well as an ATP Masters 1000 title in Paris, culminating in the Nitto ATP Finals trophy. The 24-year-old wrapped up his season with an impressive 58-6 record, as recorded by the Infosys ATP Win/Loss Index.
Sinner’s hard-fought victory against Alcaraz, where he saved a set point in the first and fought back from a 1-3 deficit in the second, has reduced his Lexus ATP Head2Head record against the Spaniard to 6-10. Vagnozzi expressed his satisfaction with how Sinner maintained composure in front of thousands of enthusiastic home supporters.
“It was an incredibly emotional and tightly contested match,” the coach commented. “Both players had moments of brilliance, but there were also times they faltered. Jannik consistently showcased his fighting spirit, keeping his composure, even during the second set when he was a break down and couldn’t find his footing.”
“We’re thrilled with Jannik’s performance. There’s definitely room for further development even after this win, as the match highlighted some areas for improvement. However, I’m truly delighted with how we capped off the season with an astounding three tournaments in a row. We’re excited to kick off the next season!”
