Yeh, yeh here we go again knife vs gun fight debate. For those that don't know the term "21 foot rule". It is well known (also called Tueller Drill) 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. The significance...