Jason Stacy’s eyes begin to glisten as his mind drifts from this New York bar back to Edwards Air Force Base in the California desert. To a night in front of the TV with his father.
‘I was maybe eight years old,’ Stacy recalls. ‘He literally had a knife poking toward my ribs.’ He wipes his eyes, apologizes and adds: ‘I don’t think about it too much.’
It is a few days before the start of the US Open and Stacy is in Midtown Manhattan, charting his remarkable journey from that airbase to the summit of women’s tennis. These days, he serves as high performance coach of Aryna Sabalenka, the world No 1 who arrives in New York chasing a third successive title.
There is science behind his methods, which help Sabalenka cope with both the rigors of Grand Slam tennis and all the off-court commitments that come with being a superstar. Sometimes his advice is to focus on the feeling of her toes; occasionally they will prepare for matches with a game of tic-tac-toe on his bald head.
But Stacy also leans on lessons mined from a punishing life. He was born in Japan before moving to the United States. His father died in his arms when he was 11. By 13, he was homeless, alone on the streets in Tacoma, Washington, where he was stabbed and shot at and held at gunpoint. He watched two friends die by suicide; he would hang outside bakeries ‘just to breathe in the smell of fresh bread.’
‘It has everything to do with how I am and who I am right now,’ Stacy says.
Jason Stacy serves as high performance coach of world No 1 tennis star Aryna Sabalenka
Sabalenka and Stacy have employed some quirky methods since they began working together
That night when his dad pressed a knife into his skin is, in fact, one of the less traumatic tales – they were watching police drama ‘Hill Street Blues’ when the topic of rape came up. Stacy asked what that meant, so his father decided to show him how to deal with a rapist. ‘This is how you would puncture their lungs,’ he recalls. ‘So they would drown in their own blood and not be able to yell out.’
Stacy’s father died from a blood clot following a motorcycle accident. His young son tried in vain to keep him breathing. Before long, the teenager was separated from his mother and siblings, too, and on a dangerous downward spiral.
After several years on the streets, Stacy sought sanctuary in a library – poring over old newspaper cuttings, burying himself in books on space and history – and in a dojo, where he rose to become a black belt in jiu-jitsu.
These days, his focus is bringing Sabalenka to the boil four fortnights a year. In a sport where some rivals change coaches almost as often as they change ends, their partnership has endured since 2018.
At first, his work centered around Sabalenka’s fitness; coach Anton Dubrov has handled the tennis since 2020. Now, though, Stacy has been christened the de facto CEO of Team Sabalenka.
Together, they have won four Grand Slam singles titles and Sabalenka could soon become the first woman since Serena Williams to win three straight titles at Flushing Meadows.
But the 28-year-old can be combustible and Sabalenka’s position as world No 1 is under threat after a testing, tempestuous few months. She has reached only one semifinal since March and recent Grand Slams have brought shock defeats followed by a desire to ‘get completely drunk’ and even ‘quit tennis right now.’ These are the times when Stacy earns his money.
Some of his techniques won’t be found in traditional coaching manuals – at the 2024 US Open, Stacy vowed to put a temporary version of Sabalenka’s tiger tattoo on his head if she made the final.
‘We were eating food right before the match… and I pulled out the tattoo,’ Stacy recalls. Sabalenka had completely forgotten. But he told her: ‘I made a promise.’ The Belarusian went on to beat Jessica Pegula in straight sets.
Sabalenka has won four Grand Slam singles titles including at the 2024 and 2025 US Open
While some players routinely change coaches, their partnership has endured since 2018
In 2024, Stacy vowed to put a version of Sabalenka’s tattoo on his head if she made the final
Sabalenka’s tiger tattoo pictured in 2023 in a Wimbledon first-round clash
Many of the American’s methods are detailed in his new book, ‘The Pressure Code’
Over the years, he has learned to spot small tells in Sabalenka’s behavior. If conversation begins veering from topic to topic, for instance, Stacy knows he needs to narrow the world No 1’s attention.
‘I would, let’s say, create a drill or an exercise that literally forces her to focus on a spot while she’s doing a certain movement,’ he says. ‘To quiet all that noise… usually that’s all it takes.’
Many of Stacy’s methods are detailed in his new book, ‘The Pressure Code,’ which explains the importance of ‘aligning’ energy, emotions and environment. The principles, Stacy writes, apply to those battling to become world No 1 and those hoping to improve their everyday life.
The book is centered around Stacy’s fall and rise. With a father in the US Air Force, the family hopped around from Japan to Germany to bases in the US. Then his father died and, before long, Stacy was on the streets.
His life fit inside one backpack and, as he survived on the outskirts of Seattle, one piece of fatherly advice never left the teenager: don’t do drugs. He never crossed that red line, even after it landed him in trouble; Stacy says he suffered three concussions from being struck in the head with a gun.
He isn’t in touch with anyone from those days. ‘Probably most are dead anyway,’ Stacy says. And among the few keepsakes he has kept hold of? ‘My birth certificate,’ he explains. ‘When I was homeless, for some reason I had it… it’s all falling apart and disintegrated.’
Stacy recently moved back to the States after more than a decade in Australia and he now lives close to Tacoma. He has driven by his old haunts. ‘It’s so weird,’ he says. That library is still standing and Stacy has reconnected with his estranged family via social media.
‘My younger sister died a long time ago. My brother’s still around, and my mother – they’re not too far from where I am,’ he says. ‘I’ll probably go see them at some point.’
His father died in his arms when he was 11 and by 13 he was homeless on the streets of Tacoma
Stacy is hoping to guide Sabalenka to a third successive US Open title at Flushing Meadows
The dojo where he found ‘salvation’ was sandwiched between a pawn shop and an adult bookstore. Day after day, he would stare inside. Eventually he decided to walk in and before long, Stacy was invited to train and even stay for free.
From there, Stacy clambered back to his feet, sometimes while juggling multiple jobs. Some days, he would work at the pawn shop before training fighters and then carrying out maintenance work at McDonald’s. By the time he’d finished, it was back to the pawn shop. Days would go by without sleep. He still doesn’t get much – five or six hours on a good night – but thankfully his work now brings more handsome rewards.
Before joining Team Sabalenka, Stacy trained as a personal trainer, a massage therapist, a sports therapist, an athletic trainer and as a strength and conditioning coach. He has studied nutrition, psychology, philosophy, history. But he never stopped listening to his gut.
‘It tells me a lot about people, their intentions, about what might be happening,’ he says. Those were skills he honed in life-or-death situations on the streets.
Stacy has also worked with Olympians and athletes across jiu-jitsu, judo and swimming. So how does Sabalenka compare? ‘They’re all a little bit crazy,’ he says. And there is another ‘common thread.’
‘When someone has a biggest strength of theirs, when they don’t manage it well… [it] can also become the biggest weakness,’ he says. ‘They’ll either climb the mountain or they’re going to destroy themselves.’
Sabalenka’s career could have unraveled when, a few years back, her serve imploded. The 28-year-old could have crumbled in 2019, when meningitis killed her father Sergey. Or in March 2024, when her ex-boyfriend died in an apparent suicide.
Instead, she is back in New York chasing a third US Open title in a row. Who knows what pranks her team will come up with this year.
‘None of this stuff’s ever been planned,’ Stacy says. ‘We spend all year just focused on performing your best, recovering great, all these things… [but] she’s a human before she’s a tennis player. And we all need to have those moments where we can just enjoy ourselves.’
