Speed Training in Golf: The Stack System Unveiled

stack system featured image swing speed

Speed training is a fundamental aspect of enhancing swing performance in golf. It involves deliberate exercises and techniques to increase your golf swing’s velocity. Think of it as fine-tuning your engine to achieve optimal clubhead speed. Numerous Tour professionals and elite amateurs have adopted a speed training program and credited it for increased swing speed and performance.

One such speed training method is the Stack System, developed by biomechanist Dr. Sasho MacKenzie and PING engineer Marty Jertson. This innovative system uses a weighted club and an app to provide customized swing speed training programs based on your abilities and swing data. By focusing on increasing clubhead speed, golfers can improve their driving distance and overall performance on the course. Professional golfers have successfully used the Stack System, which can benefit recreational golfers committed to improving their swing speed and performance.

The Stack System: A Scientific Approach

The Stack System isn’t your run-of-the-mill swing aid; it’s a meticulously designed tool backed by biomechanics and physics. Here’s the breakdown:

  • Dynamic Variable Inertia: The Stack offers an impressive array of weight combinations. By strategically stacking or unstacking these weights, you manipulate the club’s moment of inertia during the swing.
  • Dr. Sasho MacKenzie: Nicknamed “The Savant of Speed,” Dr. MacKenzie’s research and insights have elevated swing mechanics to an art form. His work bridges theory and practical application, making The Stack more than just a gadget—it’s a game-changer.
  • Dynamic Training: Programs designed in the lab – and proven on Tour – that respond dynamically as you level up your speed. Coupled with flexible hardware, AI-powered algorithms enable optimal training regardless of where you are on your golf journey.

Notable Stack System Golfers

  • Matt Fitzpatrick – 2022 US Open champion. Credited The Stack System for helping him gain seven mph clubhead speed from 2020 to 2022.
  • Bryson DeChambeau – 8-time PGA Tour winner. Known for his focus on science and biomechanics to maximize distance. Has worked directly with Dr. Sasho MacKenzie.
  • Lydia Ko – 19-time LPGA Tour winner. She started using The Stack System in 2021 and said it helped her gain 10 mph clubhead speed.
  • Charlie Wi – 4-time PGA Tour winner. One of the earliest adopters of The Stack System. Gained over 10 mph clubhead speed after adopting it.
  • Chez Reavie – 3-time PGA Tour winner – added 8 mph clubhead speed with The Stack System.
  • Ben Crane – 5-time PGA Tour winner. Credits The Stack System for helping improve his putting through the Stack Putting component.
us open trophy

Benefits for Recreational Golfers

The Stack System isn’t reserved for elite golfers with private coaches; it democratizes swing speed improvement for recreational players. The system provides a customized and scientifically-backed training methodology and caters to those looking to gain a competitive edge without breaking the bank. Average users experience significant gains—around 6 mph in clubhead speed within weeks. That’s like unlocking an extra gear in your swing.

Specifically, The Stack helps three main types of golfers:

  • Golfers looking to gain distance off the tee. Ideal for players with less than 90 mph driver swing speed who want to hit longer drives. Even a small boost can make a big scoring difference over an entire round. Shorter hitters can gain 10-15 yards to hit more greens in regulation.
  • Competitive mid-handicappers seeking an edge. Lots of potential to lower scores by several strokes through added length. Precision speed training leads to crisper strikes and more consistent contact across the bag. Plus boost confidence and enjoy the game more knowing they can reach par 5’s in two.
  • Senior golfers trying to maintain or regain swing speed as they age. The Stack counteracts the natural loss of flexibility and strength over time. Following the customized programming builds muscles in new ways leading to a powerful and repeatable motion.
swing speed

Expectations and Commitment

The Stack System requires users to follow a customized program consistently to see gains in their swing speed. The system uses artificial intelligence (AI) algorithms to create personalized training programs based on each golfer’s force-velocity profile and qualitative data on their perceived strengths and weaknesses in generating clubhead speed.  These programs are designed to increase clubhead speed over a 6 to 10-week period, which equates to 18 to 24 training sessions.

As golfers complete a program, they go through a Progress Check to quantify their speed gains. The Stack System’s AI then uses this data to rank order their next training program options, ensuring that the programs become more tailored to the golfer’s needs over time. This means that to see the full benefits of the Stack System; golfers must commit to the initial program and continue to follow the subsequent programs recommended by the AI.

The Stack System’s effectiveness relies on the user’s commitment to consistently follow the customized programs provided by the AI. By adhering to these programs, golfers can maximize their potential for increasing clubhead speed and improving their overall performance on the course.



  • Stack System Hardware: Treat it like laboratory equipment—a precise tool for serious athletes.
  • iOS Device: The Stack System runs on Apple Hardware – iPhone and iPad, Android is not yet supported.
  • Launch Monitor: Required to measure swing speed and track progress. It doesn’t need to do anything besides measure swing speed, so an expensive model is not required. The PRGR Black is included in one of the bundles, or you can use your launch monitor. Refer to our “Best Launch Monitors” post if you need help.
  • Ample Space: Swing freely without knocking over furniture or startling pets. I use my backyard practice area for this training. Refer to our “Create Your Ultimate Practice Area at Home” for help and considerations.
  • Patience and Persistence: Speed gains don’t happen overnight; they require consistent effort and dedication.

Personal Testimonial

I just completed of my “foundations” training with an increase of 7mph clubhead speed. It’s been great so far – I have adhered to the schedule, rain or shine – and it’s been rewarding seeing my numbers increase. It’s great when you reach a new personal best, and the screen flashes “New Record!” So far, I am very satisfied and looking forward to the rest of the program.

While I typically use my Rapsodo MLM2 for practice, I do have the PRGR Black as well, and because all you need for Stack training is your clubhead speed measurement, I find that the PRGR is quicker and easier to use for this purpose. Following the instructions, I place the unit on its box, a few inches above the mat and about 6 feet behind the swing’s low point.

Key Takeaways

  • The Stack System uses weighted clubs and an app to provide customized swing speed training programs based on your abilities and swing data.
  • It was developed by biomechanist Dr. Sasho MacKenzie and PING engineer Marty Jertson using scientific principles.
  • The Stack System has been successfully used by many professional golfers to improve their swing speed.
  • It can also benefit recreational golfers committed to improving their swing speed and driving distance.
  • To see results, golfers must consistently follow the customized training programs prescribed by the system’s AI algorithms.
  • You will need both a Launch Monitor to measure clubhead speed, and an iOS device to run the app.





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