TheStack 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.

eSpeed

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.