Coco Gauff’s serving woes: Searching for solutions

Coco Gauff was barely holding onto the reins after losing a close first set to Elina Svitolina in the semifinals of the recent WTA tournament in Dubai. Then, at 2-2, 15-all in the second, Gauff hit a double fault. Her shoulders slumped. She took a few steps toward her guest box and Gavin MacMillan, the biomechanics guru who joined Gauff’s team during desperate times last fall.

She appeared to address him, saying: “I’ve been doing everything you've wanted for the last six months, and it’s gotten not better at all, bro.”

This public show of vulnerability by Gauff was uncharacteristic. It was also a testament to the accumulated frustration generated by the rash of double-faults that Gauff has experienced for two-plus years now—a period during which she has led the WTA in the dreaded “Most Double Faults” category by a significant margin.

The questions loom: Does Gauff’s struggle have roots in some addressable area of technique and bio-mechanics (MacMillan’s specialty), or does she have a version of the “yips,” that awful state when the simplest of tasks—accurately throwing a ball across the infield, draining a three-foot putt, putting a second-serve into play—cannot be performed reliably?

Whether the source of Gauff’s struggles is bio-mechanical or mental amounts to a chicken-or-egg question. One thing certain is that she isn’t the first elite pro forced to deal with it. The list of players who have been in the heebee-jeebee zone, sometimes on a temporary basis, is a long and distinguished one. Among them: Aryna Sabalenka, Maria Sharapova, Elena Dementieva, Guillermo Coria and Anna Kournikova. In 2019, Alexander Zverev had a case of the yips, averaging over 13 double faults per Grand Slam match, including one 20-double fault performance in Cincinnati. And who can forget then WTA No. 1 Dinara Safina’s seven double faults in the 2009 Roland Garros final—including down match point?

“Coco, to me, is more resilient than a lot of those people,” Brad Gilbert, who coached Gauff for 14 months ending in late 2024, told me recently. “Even with the serve issues, she still won the French. She still won two majors. She’s still finished in the Top 3 in the world. I feel like if you got the yips, this mental thing, your ranking is dropping, and fast.”

The more pressing questions at the moment are, What—if anything—is wrong with Coco’s serve, and where does she go from here?

“I think [her problem], it’s 90 percent mechanical and 10 percent mental,” analyst Rennae Stubbs wrote in an email. “The problem is that the 10 percent becomes 50 percent once the serve starts going off, because bad technique breaks down under pressure.

“There are so many mechanical issues with Coco’s serve that it’s really difficult to change at this point, but I do think it’s possible. I know Gavin is trying his best.”​

Notably, Gauff was not an erratic server earlier in her career. In 2023, she was already well inside the Top 10 and, ultimately, a US Open champion. She hit only 219 double faults that year, No. 18 on a WTA list led by Ekaterina Alexandrova with 357. Gauff did not win a major in 2024, but she did bolt to the top of the dishonor roll, smacking 430 doubles. (She retained that position last year, with 431). Something changed, and whatever went wrong has stayed wrong—without knocking her off her high perch in the rankings.

MacMillan came into the spotlight as the man who fixed the serve of a woman who once was in Gauff’s shoes, Sabalenka. A prolific double-faulter early in her career, MacMillan helped Sabalenka engineer a dramatic reversal starting in late 2023. After a three-set defeat of Gauff at Wuhan in 2024—the match ended on Gauff’s 21st double fault—Sabalenka told reporters, “I was playing that match thinking, ‘Well, girl, I feel you. I feel you like nobody else.’ I know what she's going through. This is really difficult.”

Gauff and MacMillan have only been working together since late last summer, so it’s hard to draw many conclusions. But the red flags in her mechanics are still evident when things go a little sideways. Stubbs cited a problematic grip, a tendency by Gauff to drop her (right) elbow and duck under her toss, an impulse to “open up” toward the court too soon. The latter is a fault with which Tennis Channel analyst Jimmy Arias is all too familiar.

“She should come talk to me,” Arias told me recently, half in jest. “I got the yips near the end of my career. I got so anxious serving that my right hip flew open too early, making it hard to hit a good second serve. I knew what the problem was, but I couldn’t stop it, even though I kept closing my serving stance more and more, until I looked like (John) McEnroe.”

It’s 90 percent mechanical and 10 percent mental. The problem is that the 10 percent becomes 50 percent once the serve starts going off, because bad technique breaks down under pressure. Rennae Stubbs

It’s nerve-wracking for a player to consistently fail at performing a function that once came as second nature. Anxiety makes it even more difficult to produce the natural rhythm and flow on which the serve hinges. Obsessing about the serve can make matters worse, which is why supercoach and analyst Paul Annacone believes a fresh perspective on the problem can be invaluable. He noted that despite her frustration in that Dubai match with Svitolina, she did not double fault once in the third set.

“No doubles, yet she was still annoyed at her serving,” Annacone told me. “What she said to MacMillan shows that she’s got baggage, she sees the serve as a big issue. But let's be honest. How many majors has she won with, quote, unquote, a bad serve? Is it really bad? It’s not great, but so what?”

Annacone said he would be wary of tinkering with her biomechanics in pursuit of a great serve. He thinks her best path forward might lie in “reprogramming her vision.” Perhaps she should focus not on being a feared “server”—like his ace-making protege Taylor Fritz—but on becoming a “serving strategist,” like a Rafael Nadal. Concentrate on hitting her spots, look to serve wide and rip first balls, and mix up the pace and spin on her first delivery.

For his part, Arias believes that a different approach to ironing out her biomechanics might be helpful to Gauff. Simply repeating the obvious biomechanical goals—“Keep your left side up!”—probably will no longer work, he said. Everybody’s already told her that, more than once. He believes Gauff needs to find some bio-mechanical adjustment that countermands whatever she’s doing badly—a lower ball toss that calls for a quicker swing might help quell the urge to drop the left shoulder and crouch.

Hitting the serve is a wonderful, simple act—until it is not. Fixing it can become a form of rocket science or voodoo, featuring complex biomechanical equations and an abundance of psychology. Gauff’s situation is complex and puzzling, which is all the more reason for her to keep things in perspective.

As Arias said, “The most mystifying thing about all of this is how good Coco is in spite of everything.”

Annacone said he would be wary of tinkering with her biomechanics in pursuit of a great serve. He thinks her best path forward might lie in “reprogramming her vision.” Perhaps she should focus not on being a feared “server”—like his ace-making protege Taylor Fritz—but on becoming a “serving strategist,” like a Rafael Nadal. Concentrate on hitting her spots, look to serve wide and rip first balls, and mix up the pace and spin on her first delivery.

For his part, Arias believes that a different approach to ironing out her biomechanics might be helpful to Gauff. Simply repeating the obvious biomechanical goals—“Keep your left side up!”—probably will no longer work, he said. Everybody’s already told her that, more than once. He believes Gauff needs to find some bio-mechanical adjustment that countermands whatever she’s doing badly—a lower ball toss that calls for a quicker swing might help quell the urge to drop the left shoulder and crouch.

Hitting the serve is a wonderful, simple act—until it is not. Fixing it can become a form of rocket science or voodoo, featuring complex biomechanical equations and an abundance of psychology. Gauff’s situation is complex and puzzling, which is all the more reason for her to keep things in perspective.

As Arias said, “The most mystifying thing about all of this is how good Coco is in spite of everything.”