Tueller correction; parry, riposte
I stand corrected on the distance (but then people always say "Oh that Perpster, give him a foot and he'll take a yard...;-)
However, that being said, think about this. If 21 feet can be covered by an edge wielding assailant in 1.5 seconds, then it only takes 4.5 seconds for him/her to cover 21 yards. If you're caught by surprise and stealth, or you are distracted (by a 3rd person or actions/screaming/flashlight etc of the assailant), will you have time to OODA within that 4.5 seconds AND put round(s) on target? AND, even if you do, will that stop the assailant? Even a dead-on-his-feet attacker can still kill or seriously wound you just from momentum alone. The FBI shootout is a prime example (though that didn't involve edged weapons).
Here's an interesting quote from
http://www.instantknowledgenews.com/gunsalone.htm:
"Fact: Under 21 feet a knife will win every time against an untrained shooter. Many people refuse to believe this until they see an actual demonstration. Time after time, many instructors in the law enforcement community demonstrate the “Tueller” drill. They watch as the faces of our officers show concern and fear as their myth of “the gun as a superior weapon” is demolished The "Tueller" drill is a simple demonstration where a knife-wielding attacker covers the 21 feet and cuts the officer's throat with a training blade while the officer fumbles with their gun.
Knives are actually one of the biggest threats to officers. Knives are a dangerous weapon that can be employed at point of contact, creating massive permanent wound cavities, causing mechanical and biological trauma with excessive blood loss leading to shock and death. 10% of all officers who are shot in the line of duty die whereas 30% of all officers attacked with a bladed weapon die[3].
These facts become truly terrifying when we also consider that the majority of all self-defense shootings occur under 10 feet, which is well within the kill zone range of bladed weapons. Dealing with bladed weapons is actually an extremely important training aspect for Law Enforcement Instructors. We must constantly train ourselves and our officers on the latest techniques and procedures so we can defeat the knife-wielding suspect while on duty. Most knife attacks against officers occur either during the interview process within the personal space or during an attempt at arrest."
Guns have to pointed at the target and kept in alignment during firing to hit the target. Edged weapons can be completely hidden until the moment they strike, they can be aimed in any direction as the wrist/arm/shoulder of the attacker can instantly change its direction and not lose effectiveness. Think of a bullet as a killing zone of one degree of arc. It is a ray extending out from the shooter through that one degree. If the target is not in that one degree when the bullet passes the target's plane you have a miss. A slashing edge occupies a killing zone of approximately 180 degrees. There is a much higher probability, at closer ranges, of connecting with the target.
While it has been noted in this thread that slashing is not as fatal as stabbing, it is also true that slashing in certain places on the body can completely sever the vicitm's control of his/her arms. This can make fighting back or firing rather difficult.
Let's also not forget the pyschological impact being slashed or stabbed can have, which can directly effect survivability of the attack.
Anyway, I'm rambling.
