Overview

• After parting with Matt Daly in mid-August, Gauff hired Gavin MacMillan, who is credited with helping Aryna Sabalenka overhaul her serve.
• They worked together for about six days before Flushing Meadows, introducing a new motion with altered rotation and ball toss.
• Gauff beat Ajla Tomljanovic 6-4, 6-7 (2), 7-5 despite 10 double faults and six lost service games in a nearly three-hour first-round match.
• She intentionally took pace off to preserve mechanics, with first-serve averages of 88 mph in set one, 97 in set two, and 101 in set three.
• Gauff called the fast-track changes “really tough” and “mentally exhausting,” as analysts including Jim Courier view the gamble as a long-term fix that could temper short-term performance.