Lets Revisit the 21 Foot Rule Concept The 21 foot rule drill is well known within the law enforcement and personal defense circle. This defensive drill was patterned after a Salt Lake City Police Sergeant Dennis Tueller experimentation. The Tueller drill is all about "reactionary gap" through training. Other trainers have come up with the distances associated it to the Tueller drill. This experimentation, determined that the average healthy adult male can cover a distance of seven yards (21 feet) in about 1.5 seconds. Training Scar According to Force Science Research Center the old way of training was to stop...