Golf's #1 Speed Training System
TheStack pairs precisely engineered hardware with innovative, data-driven software to create custom training programs for every golfer.
Created by the Savant of Speed
Dr. Sasho MacKenzie is the biomechanist trusted by many of the world's leading golf coaches. His research has helped shift modern golf performance toward a more rigorous, data-driven understanding of how players create speed and power.
The Stack System translates Dr. MacKenzie's research into a practical training experience, giving you access to the same methods, tools, and protocols he uses when working with Tour professionals.
Trusted by Par4Success for Maximizing Your Speed
Since 2020, P4S Golf has been consistently named the Golf Digest Top 50 Golf Fitness Trainers in the USA led by Chris Finn and the hard work their entire team has put in to understanding how to help golfers play longer, hit it longer and do it all without pain.
Elite Proof
MATT FITZPATRICK
US OPEN CHAMPION
MICHAEL KIM
PGA TOUR WINNER
YUKA SASO
2X US WOMEN'S OPEN CHAMPION
MARK BLACKBURN
GOLF DIGEST BEST TEACHERS IN AMERICA
CHRIS COMO
GOLF DIGEST BEST TEACHERS IN AMERICA
TheStack | Speed Trainer | Award Winning App
Training made easy with our award winning App. Guided programs, timers, effortless data-entry, and key metrics to track your speed journey. Programs designed in the lab - and proven on Tour - that respond dynamically as you level up your speed.