Fault Tolerant Tennis is a brand for tennis nerds. I mean, what even is “Fault Tolerance” anyway? The teaching here, designed to be read by tennis nerds, was also created by tennis nerds: Johnny and Alexa.
We came at the game from two very different places – Alexa a childhood tennis phenom, winning US Open matches at the age of 15, and Johnny, an academically inclined math kid, not all that athletic, but who fell in love with the game all the same.
Despite our differences, we have one ambition very much in common – studying the game of tennis, on an endless quest to tease out any and every possible insight we can from this great sport. Fault Tolerant Tennis is the result of that ambition.
You can read more about us below.
Alexa Glatch
I’ve loved tennis from the moment I first picked up a racket at 5 years old, and I’m still in love with it today. I love playing tennis, studying tennis, striving to improve, and I love helping other players improve as well. As a kid, my passion, work ethic, and talent for the game, along with my wonderful parents, coaches, and the trainers around me, combined to create some pretty amazing results.
I won all sorts of international junior tournaments. The Easter Bowl in the 14s division, and later the 18s (though I was well younger than that at the time). The Orange Bowl in the 16s as well. Pretty soon, I was competing at junior majors and made the finals of the French Open in doubles. After the French, I played the junior US Open, my home slam, and made both the singles and doubles final. In 2005, even though I was only 15, I was the #5 junior player in the world, and I decided to go pro. I qualified for the main draw of the US Open that year and won my first round, before losing to Jelena Jankovic in the second.
By 2009, I was playing quality WTA-level tennis, on the verge of the top 100, but one fateful day on a motor-scooter, that ended, at least for the time being. I crashed, and needed some pretty serious surgery to recover. Unfortunately, as we’ll get to later, that kind of misfortune ended up becoming a pattern throughout my career.
After the accident, I received a wildcard into the US Open. At the draw, they select the opponents of the top seeds last. I sat there, listening to name, after name, without my name being called. Finally, we got to the draw for Serena Williams’ opponent, and mine was one of only two names left to be picked.
“Alexa Glatch.”
The timing was not ideal, to say the least. I’d barely played, barely practiced, and was in a hospital bed a few months ago, but it was time to play the best player in history on Arthur Ashe.
Throughout my career, I tinkered with my forehand and serve often. It’s not like they were bad shots – my serve was actually pretty good, but I just knew they could be better. Neither one felt like my backhand, my true weapon on court. I got out there against Serena, rusty as could be, and began cracking backhands like I’d never left. I missed forehands (a lot of forehands), and I didn’t hit many aces, but I was ripping the backhand as cleanly as ever. That was my shot. I actually broke her serve with it in the first set.
I wanted that feeling for every shot. I experimented, tweaked, and tested nonstop, always reaching for that next level. It wasn’t enough that my forehand was merely good, or that I could ace WTA players with my serve. I wanted them to be the best they could possibly be. My quest for better tennis performance naturally evolved into a quest for knowledge and understanding. I studied the best players, read every coaching resource I could find, and worked with countless different people, each of whom had different ideas and methods, all on a mission to improve my own game. The drive towards continuous improvement that permeated my tour life is part of the reason I’ve taken so naturally to coaching now that I’m retired. After so many years of playing, I have so much I want to give back.
Playing on tour was both thrilling and frustrating. The tennis part was amazing. Tennis is what I was born to do. Getting injured, though – that was difficult. The pattern of my career was a cyclical one – win a bunch of matches, get my ranking up close to the top 100, and then suffer a debilitating injury that leaves me unable to practice, which sends my ranking plummeting back down into the abyss. Rinse and repeat. I did manage to crack the top 100 in doubles, and basically got there in singles as well, but those results are a far cry from beating Petra Kvitova 6-2 6-1 when we were teenagers. Discipline, patience, and toughness were my greatest assets throughout this whirlwind of matches, ranking points, and hospital beds, and the thrill of playing at the highest levels of our sport, on the biggest stages in the world, was worth all the setbacks and struggle.
Coaching lets me help players avoid some of the same mistakes I made, lets me leverage my unique experience to help them maximize their own ability. What I really like is the challenge of figuring out how to get the most out of each player, how to take their unique talents, skill set, and game, and help them reach their highest potential. It pushes me to think about the game in new and interesting ways, and I love the chance to have a direct impact on someone else’s growth. It’s a constant learning process, as every student presents a new challenge. Seeing someone improve, whether it technically or mentally, is incredibly rewarding. There’s nothing like that “aha” moment when a player finally gets something they’ve been working on.
As a junior, I was blessed enough to have amazing people around me. Now, I want to be one of those people, a coach who can guide the obsessed 16-year-old phenom, who’s craving improvement at every turn, to get the absolute most out of her mind and body. I’ve been that 16-year-old phenom. I know exactly where she’s been and how to help her where she’s going, and I’m still just as in love with our sport as I was on day one. Honestly, I couldn’t see myself doing anything else.
Johnny Kumpf
I was never a tennis player by trade. When I picked up the game as a teenager, I never thought I’d make a career out of it. Like a typical math kid, I went to college, majored in Computer Science (and Electrical Engineering) at Duke University, and figured I’d end up a software developer like most of my peers.
I only started to study tennis seriously my final year of school, when I happened upon a few random forehand cues that actually worked, like preparing with the elbow up, and I got very curious as to just how much more I might be missing. Back as a 13-year-old beginner, I’d already known I was missing something. I’d hit one or two great shots, but could never repeat that. Everything coaches told me was just… off. It never really worked the way I wanted it to work. Never quite made sense, never quite fit into a coherent whole. The advice felt like a bunch of random cues grafted together into a slew of unrelated ideas, rather than a set of recommendations generated from a sound, underlying model for how quality tennis was played, and effectively trained. Gradually, as I studied the game myself, that underlying model began to take form.
After graduating college, I did work as a software developer for two years, still studying tennis on the side, but quickly quit development out of a combination of boredom and frustration with the corporate environment. I took up tennis coaching more seriously, as it was much more interesting than plumbing JavaScript libraries together, and, just as importantly, it was much more personal.
At my core, I’m still an academic. Most of my God-given talents are mental, not physical, but I think that’s actually part of why tennis compels me like it does. I’m not naturally good at it, like I am at most things. I had to search, and test, and fail, over, and over, and over again in order to get even moderately good at this sport. Tennis is such a fascinating game, because it’s so incredibly skill-intensive that, no matter how hard you’ve already looked, you can always still unearth new insights into its laws. I’ve scoured the depths of the information landscape across all sports in order to bring you those insights. From baseball, to cricket, to basketball, to even juggling, the human body is the human body, and cross-pollination from work done in other disciplines has led me to some of my biggest tennis breakthroughs.
My process for learning the game was essentially the scientific method, but applied to tennis. Form a hypothesis, design an experiment, test, iterate. I watched coaches, read papers, and clicked, frame-by-frame, through hours and hours of slow motion footage, all with one goal in mind: uncover the underlying fundamentals that underpin effective tennis. Develop an accurate model that explains why the best players are the best, and then test that model against reality to see if it actually makes players better.
Become the coach I wish I’d had as a teenage beginner.
In 2020, I began teaching at a local club. During that time, my first test subject for any new idea was always myself, and if a new concept or training technique worked when I implemented it, I’d introduce it to my students, to see if they’d derive benefit from it as well. Many ideas failed, of course, but many also succeeded, and pretty soon I’d developed an expansive mental library of concepts, cues, and training techniques that could address a myriad of different woes a student might have.
Out of the wide array of tennis concepts that exist, the forehand has always intrigued me the most. It’s the area to which I’ve dedicated the plurality of my research, and it was the area that first caused me to notice that the human brain is far from the optimal hardware on which to instantiate an ever-growing comprehensive library of tennis ideas. I’d frequently have experiences, both with my own forehand, and with my students’, where something would go awry, and for a day, or a week, I wouldn’t be able to fix it, only to realize that the solution was something I’d already discovered 6 months ago, but had since forgotten. I needed a record. A durable, permanent, accessible record of the progress I’d already made, lest I get stuck in an endless loop of re-discovering old concepts, rather than building on top of those old ideas as I forge ahead into the current unknown.
I began Fault Tolerant Tennis and authored The Fault Tolerant Forehand as my first attempt to synthesize everything I’d learned, which had helped both me, and my students, so much, into that long-term, evergreen record. The model of the forehand detailed in the book is still, in my humble opinion, the best that exists online today, and though I’d rewrite about 20% of it now, and I will in a second edition next year, in its current form, it holds up extremely well as an irreplaceably useful resource.
While coaching, I also did a two year stint as a professional gambler. It’s not like I suddenly became bad at math after I changed my career, so might as well take advantage of it. I’d coach during the day, get home right as basketball tipped off, and then bet straight through until the games ended at midnight. I won a lot before finally getting kicked off of every high-limit sportsbook in New Jersey. It was a stressful, thrilling, and fulfilling chapter of my life, but despite the financial success, the work was still missing one critical element – making other people’s lives better. Winning $100 because a 19-year-old on the other side of the country made exactly one free throw to end a 72-51 blowout is great, but you know what’s even better? Getting tipped $100 because my 3.5 student had finally blown his 3.5 pusher friend off the court, after losing, and losing, and losing before.
As luck would have it, right as Caesar’s Sportsbook, my final high-limit book in NJ, kicked me off, I got back in touch with Alexa, with whom I’d worked in the past. The stars were aligned to partner up and take Fault Tolerant Tennis to the next level. My only reservation, to this point, had been that, as merely a strong amateur player, I wondered if I had blind spots when it came to truly high level tennis. Maybe certain things I thought were fundamental were actually capped, and only worked up until a certain point. With Alexa on board, that’s no longer an uncertainty. Everything we work on now gets processed through the filter of someone who has played at the highest level, and by the time you see it, you can rest assured you won’t hit any unforeseen plateaus working it into your game.
For a while, tennis coaching was a secondary pursuit – a passion project I pursued while working other jobs. Eventually, though, the signal that this was something special became too strong to ignore. My students were going from losing horribly in the first round of tournaments, to winning the entire event. Adults who’d found my work were getting computer bumped entire NTPR points in one season, and glowingly recounting to me how much our teaching had improved their game. I partnered with Alexa, doubled down on Fault Tolerant Tennis, and started our YouTube channel to explain the ideas that are difficult to explain in print. Our mission is to make this place the most comprehensive, insightful, useful tennis resource on the internet, a Library of Alexandria for anyone looking to master our sport. I think we’re well on our way, and I’m continuously excited by what I might discover next.