A performance block, also known as the yips, choke, glitch or monster, is a potentially career-ending, mentally crushing condition that causes a player to freeze and forget how to perform movements that were once simple and routine. It is experienced as a trauma; complete with fear, rising blood pressure, sweaty palms, anxiety, and tension.


performanceblocks     Left to right: Dr. David Grand, Mackey Sasser, Rob Polishook, Dr. Alan Goldberg at Shea Stadium before a game (2006)


Performance blocks, aka yips, choking, glitch, slumps, and the monster, usually rear its ugly head under pressure and seemingly completely out of the blue. Years ago, the infamous Steve Blass of the Pittsburgh Pirates coined his experiences with the yips as the “The Monster!”





The Mackey Sasser Story


"Everyone kept saying I had a phobia," Mackey Sasser said. "I didn't have a phobia. I just had a lot of things built up inside of me. Rob Polishook and Dr. David Grand taught me how to release all of that and just let it go...Read More in Sports Illustrated, June 7th, 2010


mackeysasser     Mackey Sasser, former NY Met and current coach of the Wallace Governors in Dothan Alabama said “I feel like a 500 pounds weight has been lifted off my shoulders. I can throw batting practice to my college team without any problems thanks to these guys.”


Exclusive Interview
Rob Polishook Interviews Mackey Sasser


Exclusive Radio Interview
With Dr. David Grand, Mackey Sasser on ESPN


Exclusive (Untold) Mackey Sasser Story
By Dr. Alan Goldberg





Articles on Performance Blocks





The Yips
Nicknames, Nomenclature and History

Slumps, Chokes, and the Yips
Understanding Performance Blocks


Performance Blocks
Symptoms, Causes and Resolution


Fight, Flight, Freeze
The Seven Biggest Fears That Paralyze Athletes in Sports


Tension, Tears, and Twitches
The Secret to Managing Stress


Broken Rackets, Bad Body Language
Solving the Problem by Addressing the Cause