The Stack Speed Training System


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  • Software Requirements

    The Stack Speed Training Systems accompanying app, is only available via the iOS app store

    Radar Recomendations

    The Stack Speed System highly recommends an accompanying launch monitor for effective improvements. Please find a list of recommended launch monitors below in the 'Compatible Devices' tab



The Savant of Speed
The Stack System provides dynamic programming directly from golf's leading biomechanist. Speed training secrets previously reserved for Tour players, now available to you.

Precision Hardware
5 CNC milled Stack weights combine with a custom engineered shaft & hardware to create 30 unique combinations for unlocking dynamic variable inertia speed training.

Dynamic Training
Programs designed in the lab - and proven on Tour - that respond dynamically as you level up your speed.

Tracking Speed
You'll need a speed tracking device to get started. We prefer the PRGR Black Pocket, but TheStack is compatible with other options. See the list of options in the 'Compatible Devices' Tab

Guided Programs Based On Your Initial Baseline
Initially, each golfer is piloted through a series of swing speed tests to generate a force-velocity profile of their current swing. Qualitative data is gathered on perceived strengths and weaknesses related to generating clubhead speed.
Based on individual comprehensive baseline data, TheStack App’s artificial intelligence (A.I.) algorithms provide a list of customized program options. The program list is rank ordered starting with the program that has the greatest likelihood of increasing clubhead speed over a 6 to 10 week period, which equates 18 to 24 training sessions.

Timers Tell You When To Swing, And When To Rest
TheStack App provides customized variable inertia speed training - the most efficient way to increase your clubhead speed. The algorithms that power the dynamic programming come from years of research by leading sport scientist, Dr. Sasho MacKenzie. TheStack App is available on iOS and requires iOS 13.0 or later.

Enter Your Speed Data Hands-Free
Using TheStack System’s voice entry technology, enjoy hands-free data collection during training sessions, by simply dictating your speed readings into the App. The hands-free data capture feature even works when wearing AirPods or earbuds. If you are training with a coach or friend, numbers can be keyed.

Track Your Progress With Custom Metrics
TheStack has streamlined your performance variables into 4 key metrics. Stack Speed, Speed, Distance Potential and Grit Score. Learn More

Additional information

The Player




Standard (41.5"), Junior (38.5")

Product Type

Golf Accessories

Compatible Devices

Radar Devices and Integration
Tracking speed is not as easy as it sounds. At TheStack System, we analyze nearly all radar devices that track training swings and TheStack App factors out any bias, or systematic error, in speed measurements that are associated with our hardware design. What does this mean to you? If your radar measures with a bias, our smart algorithms adjust for it and accurately calculate your eSpeed and Distance Potential regardless of which device you are using.

Brand Model
PRGR Black Pocket, Red Pocket
Garmin G80
Swing Caddie SC200 PLUS
FlightScope X2, X2 Elite, X3, Xi Tour, Mevo+ *see notes below for the Mevo+
Sports Sensors Swing Speed Radar®
Yupiteru GST-5, GST-7 BLE

The PRGR is great for training with TheStack. It is small and packs into your golf bag easily, and gives the added benefit of being a great device to bring onto the golf course to measure ball speed while playing.

Swing Caddie: SC200 Plus
The Swing Caddie SC200 Plus is a portable launch monitor that measures both swing speed and ball speed. Swing Caddie recently added Swing Speed Mode to enable training with TheStack. You can order a Swing Caddie

Garmin: G80
The Garmin Approach G80 is a unique product that is both a radar and GPS device in one. As of March 2021 you can update your software to Version 3.30, or newer, using Garmin Express and be able to track training swings. You can order a Garmin G80

Mevo+ (Device Notes)
Flightscope added Swing Training Mode to the Mevo+ through the FS Golf App for iOS/Android. You will need FS Golf App version 4.0.0 or newer. To use the Mevo+ with TheStack App, you will need two separate devices (example: iPad to run the Mevo+ and iPhone to run TheStack App, or Android phone for FS Golf App and iPad for TheStack App).

The Stack Metrics

TheStack has streamlined your performance variables into 4 key metrics.

Stack Speed
Your Stack Speed is the radar measurement of TheStack when configured to represent the inertia of your driver. This Stack configuration is referred to as the standard Stack weight.

TheStack’s shaft length is equivalent to that of a typical hybrid club, but most golfers are familiar with and care about their driver speed. TheStack’s eSpeed (Equivalent Driver Speed) provides a reasonable approximation of your driver clubhead speed based on the length differential between TheStack and your driver.

Distance Potential
While clubhead speed is crucial, driving distance is ultimately what matters. TheStack’s Distance Potential metric converts eSpeed into driving distance.

For the Distance Potential metric, we use the following:

  • 90° F temperature
  • 1,000 ft. elevation
  • Total distance (carry + roll)
  • Moderately firm fairways
  • Neutral Angle of Attack
  • Optimized launch conditions (club fitting efficiency)
  • 2019 ProV1x Ball
  • You will only see Distance Potential when training with your standard Stack setting. We do not show it for lighter or heavier settings.

Grit Score
TheStack System’s Grit Score quantifies your tenacity to pursue long term goals. Train as prescribed to earn a grit score of 100%. Deviations from the prescribed rep, set, and session rest lowers your Grit Score. If you are a coach tracking a student’s compliance to training, Grit score is the single metric on which to focus.