Gavin MacMillan's 600-Serves-a-Week Method to Fix Coco Gauff's Game
Biomechanics Expert Gavin MacMillan, Who Fixed Aryna Sabalenka's Serve, Now Aims to Elevate Coco Gauff's Game
In 2025, Coco Gauff enlisted the help of Gavin MacMillan, a biomechanics expert and physical trainer known for fixing Aryna Sabalenka's faulty serve.
"It's incredible. She had already won a Grand Slam, but she still wanted to improve," MacMillan shares.
The MacMillan Method
MacMillan illustrates his approach with the example of Sabalenka:
"If you look at Aryna Sabalenka, in one of her early finals against Elena Rybakina, she committed six double faults.
But a year later, she only made six double faults in the entire tournament.
This is due to a year of confidence in the process, so that under pressure, the brain says: 'If I keep going like this, I'll get there.'"
He emphasizes: "It all depends on your expectations. If you think you can serve like a pro overnight, well, we're deluding ourselves.
In tennis, it's hard to stay patient, because you're constantly reminded when you're not playing well. So, it's difficult to believe that long-term work will pay off."
Repetition and Neural Integration
Improving a serve requires methodical training. MacMillan applies the same method he used with Sabalenka: 500 to 600 serves per week, up to 20,000 per year.
"The brain must integrate the movement, make it automatic, and only then will the results appear.
However, we are limited: you can't do more than 70 or 80 serves per day due to arm constraints. So, you have to increase gradually.
Maybe 500 to 600 serves per week, about 2,000 per month, and around 20,000 per year.
Then, we evaluate: is the pattern improving? There is no magic solution. Believing otherwise would be deluding ourselves."
His Role Within the Gauff Team
MacMillan stresses the importance of collaboration with Gauff's team:
"Concretely, I'm here to improve the quality of her shots. But it's a team effort.
For example, Jean-Christophe Faurel (Gauff's coach) is very competent; he's been immersed in tennis forever and knows her much better than I do."
Although his hiring primarily aims to improve her serve and forehand, MacMillan works on all aspects of the game in coordination with the team.
"Everyone knows I was hired to help her with her serve and forehand, two areas that were problematic for her.
But we discuss everything. Nothing is presented to the player without us having discussed it beforehand as a team. It's important to leverage everyone's experience; otherwise, it would be a mistake.
A lot is expected of Coco Gauff. But to me, she's the best athlete on the tour. Her backhand is phenomenal; no one can beat her in speed.
So, if we improve certain aspects, we'll see what she's capable of. And clearly, I believe in it, otherwise I wouldn't do it."
