On a Saturday last August, Patrick Knott was in full prep mode on the range at Merion Golf Club in Ardmore, Pa., after a morning win in the club championship quarterfinals. His next match was in an hour, but he didn’t like what he was seeing from his iron shots. So he grabbed his phone, filmed his swing and sent it out for a quick look.
“The feedback told me what I thought—I was pushing my hips toward the ball on the downswing,” says Knott, 40, who is a +3-handicap. “I watched a quick drill video and a clip from Justin Rose to get a feel to play with. I knew right away this was going to help.”
Patrick found the groove and won his semifinal that afternoon, and a week later he was celebrating his fourth championship at Merion.
Where did Patrick send his swing? He uploaded it into an app called Mustard Golf, which he’d been using for a few months to learn about his technique and how to improve it. Mustard provides users with swing advice using a motion-analysis algorithm that measures every position in the golf swing, prioritizes any outlier moves and creates a personalized plan for improvement with top teachers.
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Many golfers looking to play better either seek out a local pro for lessons or try to find tips themselves, usually online. Both methods can work but present potential problems, like the cost and inconvenience of private lessons or the generic nature of mass-market instruction. In short, golfers don’t always get what they need when they need it.
Golf Digest saw this gap and partnered with Mustard to develop the app, which is inspired by the personal attention golfers get from face-to-face instruction and the easy access of online learning. It’s a fully remote, user-driven platform with lesson-level reliability.
Call it DIY with an expert eye.
Golf Digest and Mustard, a sports-technology company that has roots in baseball and was co-founded by legendary MLB pitching coach Tom House, had one goal: to put great coaching in the golfer’s pocket. Through motion-capture technology and a digital filtering system, golfers using the app can access instructional content from Golf Digest coaches that applies specifically to their swing. The result is personalized coaching delivered at scale.
How It Works
To get started with the Mustard Golf app, users record a single swing video looking down the target line or upload one from their mobile phone. The app then uses an AI-powered analysis program built on data from thousands of pro and amateur swings to produce a report—in about a minute—on the basic structure of the swing.
Although swing metrics drive the analysis, the app does not share raw swing data with users. Instead, it uses the data to grade various parts of the swing on a simple 1-10 scale. The data informs the grading but is not a deliverable to the user. This mirrors the way top golf instructors use technology in lessons: They share what students need to know, not everything the technology reveals.
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For simplicity, the Mustard analysis breaks down the motion into the backswing and downswing and looks at two movement patterns: (1) how the hands and arms direct the club and (2) how the body moves to support the swing. The “expert eye” in the app is powered by computer-vision technology, which locates all the major joints in the body, tags them and tracks their movement throughout the swing.
But capturing motion is only the first step. The app ultimately relies on teaching smarts—the ability to search for certain swing positions and quickly assess them. Mark Blackburn, who is Golf Digest’s No. 1 Teacher in America, Justin Rose and a team of top instructors and 3D-motion experts identified the most consequential movements in the golf swing—the ones that most affect the shots a player hits—and developed a protocol for measuring and prioritizing them.
The result is a set of 12 swing variables that describe the movement of the hands, arms and body, including things like swing path, shoulder and hip turn and dynamic posture. These pieces in large part determine the functionality of a player’s swing. Blackburn and team established tolerances for each variable to create, in effect, a pass/fail system that drives the user’s improvement plan in the app.
But not all swing variables are created equal. Blackburn and team developed a swing hierarchy to assign relative importance to each piece. When a variable doesn’t measure up, the app flags it and looks at where it sits in the hierarchy and when it occurs in the swing. The lowest grade in the most important area gets priority, the same process great teachers use with their students.
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“When I’m looking at a player’s swing, I look for the first domino to fall,” Blackburn says. “If I can find something in the setup or backswing that’s negatively affecting impact, I’m going there. Faults early in the swing tend to snowball, plus you have more time and space to fix them before impact. We built that logic into the app.”
Mustard’s system of identifying what’s working and not working and knowing the comparative value of each variable is the app’s secret sauce. It drives a core directive: what to work on first. This is the very issue that plagues most golfers—they don’t know where to start, so they pick blindly or skip around. The app’s ability to determine a clear direction by sorting out what matters most in a specific swing is the unique promise of Mustard.
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Once a user’s swing analysis is complete, the app presents a step-by-step plan for improvement, starting with the swing variable that emerges as the top priority. The app then takes the user through the potential causes of the problem, like a faulty setup, an off-line takeaway or a misconception about how to create power. Understanding the why in the what is critical to fixing technique.
The app then turns to personalized instruction, which is the centerpiece of the user’s experience. The instruction hub contains hundreds of videos on corrections and practice drills keyed to the 12 swing variables. In this part of the app, there is some personal choice because learning is never one-size-fits-all.
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“I might think a certain drill is perfect for a student, but if it doesn’t connect with them, it’s useless,” Blackburn says. “Good teachers have many ways to attack a single issue. We designed the app to let players experiment, after we get them on the right track.”
“I’ve worked with some great teachers, and they’ve always given me multiple drills to cycle through,” says Knott, the Merion club champ. “I use Mustard the same way—going back and forth with the different drills for my specific issue. Having a single focus and lots of ways to address it, that’s the best thing about Mustard.”
Users are prompted to pick instructional content that fits their learning style, feels at the right level for them and produces noticeable results. They also can favorite lessons and drills, and the app provides many tools for them to manage their practice, find fresh content and adjust their plan as they go.
Your browser does not support the video tag. Taking a Deeper Dive
The Mustard Golf app’s methodology and capability also draw from the top echelons of the game. Rose, a major champion and former World No. 1, is a Mustard investor and advisor and helped develop the app's diagnostics. The process Rose uses to keep his own game on point is part of the Mustard experience.
“When I’m not hitting the shots I want, I almost always go back to things I’ve worked on for years,” Rose says. “Every golfer has a swing pattern, and when you understand those things that keep cropping up, improvement comes a lot quicker. This app can help you find and fix them.”
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Going a step further, the app also looks for combinations of moves; for example, what’s happening in the backswing to cause the structure of the downswing? When the app detects a common combination, the analysis follows Blackburn’s “first domino” approach: It favors the swing variable that promises the quickest, most doable change.
“As teachers, we always see swing combos, like a backswing that’s too far inside leading to a casting motion with the arms from the top to try to get the club back on line,” says Michael Jacobs, another Golf Digest top-10 teacher on the Mustard instruction team. “Just about every golf swing has offsetting moves like that.”
These adjustments, called matchups, are the most effective way to move technique that is too far one way or another back toward neutral. Trying to create a textbook-perfect swing is widely considered unrealistic; effective swings have the right corresponding pieces. This reasoning is behind much of the app’s instructional content, mainly lessons and drill demonstrations from Blackburn, Rose and other leading experts.
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Staying on Track
The last critical piece in swing improvement is progress tracking, which in the app starts with uploading additional swings for analysis. With a new set of measurements, the app assigns revised grades on the 12 swing variables. This process either confirms the user’s original plan or presents a new one, again simulating how golf instructors adapt on the lesson tee.
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Mustard user Shaun Corpron, a 5-handicap from Lexington, has had his swing analyzed many times at a high-tech golf facility. “When I got the app, I already knew my problem was too much upper body on the downswing. Mustard nailed it in one swing, so I dug into the drills. In a few weeks, I went from scoring a 4 or 5 in that area to a 9 or 10. I was blown away, and I could do it all on my own.”
Another tool instructors use to help golfers check progress is the use of slow-motion swings. Motor learning relies on clear, repeated training, and slower is better when trying to acquire skills or break habits. The app’s slow-motion feature allows users to check their swing positions in real time using their phone camera.
As the user makes a slow practice swing, watching their phone screen as if looking in a mirror, the app gives an auditory grade of 1-10 for each swing position. By pausing and making adjustments to their club or body, the user can see the difference between, say, a “5” and a “10.”
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“It’s much easier to perform something slowly, then add speed as you get better at it,” Blackburn says. “Mustard’s Slow-Mo Drills give immediate feedback, showing the player what perfect feels like and how to get from where they are to where they want to be.”
Like with any form of learning, commitment comes from confidence. The golfer has to trust the accuracy of the analysis, the organization of a plan and the credibility of the advice. Mustard’s industry-leading technology and partnerships with the game’s top instruction experts have set the stage to democratize great coaching.
To check out the Mustard Golf app, have a swing clip handy or shoot one in the app (first swing analysis is free). Get the app here.
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