Gauff’s service overhaul ahead of the WTA Finals
Coco Gauff works with Gavin MacMillan to fix service inconsistencies after recording 405 double faults during the 2025 season. The world number three aims to stabilize her motion to maintain dominance ahead of the 2026 WTA Finals in Riyadh.
Coaching shifts and service errors
Coco Gauff struggles to stabilize her serve as the 2026 WTA Finals in Riyadh approach. She recorded 405 double faults throughout the 2025 season. This inconsistency led her to end her 14-month partnership with Brad Gilbert. Gilbert coached her through victories in the 2023 Cincinnati Open and the 2023 US Open. Gavin MacMillan now works with the 21-year-old to improve her service motion. MacMillan, who recently spoke on the Tennis Channel, offers advice to help players combat service flaws. Gauff attempts to emulate the service tweaks used by Novak Djokovic to increase her dominance. The 21-year-old American aims to minimize these errors to maintain her dominance after winning the 2024 Roland Garros and 2023 US Open.
Gauff holds the world number three ranking. She also won the Cincinnati title and the 2024 Roland Garros title. These successes came despite her struggle to maintain a consistent first serve. In 2025, she hit 178 aces and maintained an average serve speed of 104mph. Her second serve percentage sat at 43.2% throughout the year. Her ability to win 58.8% of her serve points shows her effectiveness when she lands the ball.
| Service Metric | 2025 Statistic |
|---|---|
| Aces | 178 |
| Double Faults | 405 |
| First Serve % | 61.7% |
| Second Serve % | 43.2% |
| Average Speed | 104mph |
| Serve Points Won | 58.8% |
Mechanics of the service motion
MacMillan teaches that the left arm dictates how a player rotates and moves upward. Gavin MacMillan explains that if the left arm pulls open wide to the left during a forehand, it causes over-rotation which prevents a player from getting their body underneath the ball to hit up with proper height. This positioning allows a player to get under the ball instead of hitting it flat. Gauff needs this adjustment because she lacks the height of much taller players. You should note that she can draw inspiration from Aryna Sabalenka, who faced similar service issues in 2022.
Gauff reached the final of the 2026 Miami Open after winning four consecutive three-set matches. She lost that final to Sabalenka, who possessed too much firepower. Gauff held her nerve during close moments but ultimately fell to the superior power of the Belarusian. Navratilova noted that Gauff held her nerve well during that match. Gauff’s serve remains her most significant weakness. This lack of service consistency remains a glaring flaw in her game.
The road to Riyadh
The 2026 WTA Finals in Riyadh hosts the eight best players from the season. The group stage draw divides these players into Purple and Orange groups. The top two players from each group advance to the semifinals. Gauff must maintain her top three ranking to secure her place. She aims to build on her 2023 US Open triumph and her 2024 Roland Garros title. The competition in Riyadh remains fierce as players like Rybakina and Swiatek prepare for the season finale.
The prize pool for the season-ending event reaches $15.25 million. Gauff faces a field that includes players who have recently won titles in Madrid and Rome. She aims to improve her serve to match the high-level competition. She must finish in the top two of her assigned group to advance. Gauff remains in the mix for the world number one ranking following the US Open. Gauff’s performance in the group stage determines her ability to reach the knockout rounds. Will MacMillan’s technical advice provide the stability Gauff needs to win her next major title?
