Saturday, April 6, 2013

Don't bring a gun to a knife fight - The 10 foot rule

Wild West desperadoes, Chicago gangsters (see Sean Connery in The Untouchables), 1870s Samurai, and the average 21st Century firearm enthusiast are all familiar with one time honored aphorism: "Don't bring a knife to a gun fight". It's a phrase that seems to pass both the common-sense test and the test of time. A closer examination of the knife/gun showdown, however, reveals a different picture. Even though firearms replaced swords on the battlefield, blades are still just as dangerous in interpersonal violent crime. And at close range, they are actually even deadlier than a gun.

"No thanks, I'm gonna stick with the F-14."

This article draws inspiration from the so-called "21 foot rule", coined by Utah police officer Dennis Tueller in 1984. Tueller claimed that officers could not draw their guns and shoot a knife-wielding attacker who charged from 21 feet away. Fortunately, as numerous YouTube videos show, Tueller's rule is a bit too conservative; defenders with a gun are actually fairly safe at 21 feet, especially if they are well trained, have already racked their weapon, fire from the hip, and sidestep off the line of attack. But even just 5 feet closer, the advantage returns to the knifer. 

In this article, I offer an equally terrifying revision to Tueller's initial theory: The 10 foot rule. Gathering a wide range of martial, mathematical, and physical evidence, I will show:
  1. At 10 feet away, a knifer will be able to reach and stab a gun-toting defender, even if the gun user has his hand on his holstered weapon, draws fast, sidesteps, and is 100% aware of the impending attack (unless that defender ALSO fires from the hip, which is itself an extremely low-accuracy shot). 
  2. Even if you are skilled and lucky enough to get a gun out in this tiny window, your chance of hitting the target is low, and that's assuming you are firing from a stance and not the hip. Trained police officers only have a 38% hit rate at 0-2 feet when under stress!
In presenting my case, I call into question the fake sense of security that many civilians and professionals have in carrying a gun, emphasizing the need for increased training in unarmed knife defense.

Even during the 20th Century, neither martial artists, soldiers, nor police officers ever doubted the effectiveness of blades. World Wars 1 and 2 saw countless knife fights and melee encounters, evidenced in accounts of English soldiers and tales of trenchfighting from literature. Special forces units across the globe to this day train extensively in blade techniques. This emphasis arose not only from grisly battlefield realities, but also the lessons of East Asian martial arts. Filipino and Indonesian systems in particular, like Kali, Arnis, and Silat, focused around armed combat, and were an important source of inspiration for much of the literature surrounding knives and guns. Dan Inosanto, a colleague of Bruce Lee's and a master of Silat, offered a powerful video testament to the danger of knives at close range. You only need to watch the first 60 seconds to get the idea:

Innosanto's exhibition is hardly a "scientific" study of knife effectiveness, even if it is a memorable demonstration. And yes, we can criticize these officers' reaction from our cozy rooms, but unless you have either participated in those kinds of drills or been in those situations, you won't understand the danger. Under stress and pressure at close range, a reactive gunman will often lose to an active knifer. Silat, Kali, Israeli martial systens, and other modern knife systems obviously do not teach students to assault law enforcement personnel, but they do teach them to honor the power and art of the blade.

It was this sort of knowledge that forced Sgt.Tueller to define the 21 Foot Rule. In making that rule, Tueller observed that officers needed to know the dangers against close-range knife wielding attackers. With a gun on your hip, it is easy to be too comfortable when facing down a suspect, even one who is potentially armed. But as Tueller, Inosanto, and other professionals showed, the knife remains a real danger to anyone, even (or especially!) armed police officers.

These dangers are compounded by the effects of stress on a body. Rory Miller, martial art author, correction officer, and all-around authority on stress training and fighting, explains the physical and mental deterioration that occurs under stress. Fine motor control disappears (to simulate this, sprint up and down the stairs for a minute and then try a typing test on your computer). Reaction speed slows to a crawl. Some people freeze under fear of harm and death. Others panic and curl into a protective ball. Everything might appear to happen in slow motion, or everything might be a blur of high-speed movement. Auditory and visual exclusion are common in these situations. You won't remember or hear a loud gun shot or see the color of the attacker's jacket, but you will hear his shoelace pattering against the ground as he runs, or recall the color of his earring.

Even with training, these influences make it extremely difficult to execute any precise physical movements. Drawing a weapon, especially from a concealed holster, becomes harder than an egg-in-spoon race while hopping in a burlap sac. Your coordination decays to that of a child, and that's assuming you drilled the movements extensively. Without such rigorous stress-training, you won't be able to lift your hands in surrender, let alone draw and fire a gun, let alone draw and fire a gun on a charging and crazed attacker.

Tueller and his law enforcement colleagues are all fully appreciative of these afore-mentioned factors of time, distance, and stress. But even when dealing with expert opinion, it is always nice to have a new perspective on a problem. Working in the name of science, Adam and Jamie of Mythbusters fame also tested Tueller's rule in an episode on gun myths, confirmed a 16 foot kill (the exact time of which is linked here). Of course, numerous internet communities have questioned the conclusion; Adam (the defender) could have fired from the hip, pre-racked his gun, been a better trained carrier to begin with, and actually been under stress. It's a good test and an entertaining video, but it has a lot of room for improvement. Following these criticisms, I wanted to simulate the same test using different methods.

To rerun the test without the camera and digital technology of Mythbusters, I needed to use some numbers. This involved calculating both the running speed of an attacker and the gun draw speed of a defender under stress.
Rich Eisen: Standard
Chicago criminal
We need to assume an average attacker without any exceptional athletic ability. Obviously, if Usain Bolt charged you with a knife, you would be screwed. But given that individuals with multi-million dollar talents for speed are generally not criminals, we need to look at a more average running speed. To calculate this, I took measurements from unorthodox sources: Jamie in the Mythbusters video, and the running speed of NFL Network's Rich Eisen. Rich Eisen is somewhat of a mini-internet sensation for his annual 40 yard dash tradition at the NFL Combine. You can see his 2012 attempt here, and even if you are only passingly familiar with running, football, or announcers, you will find it hilarious. Why use these sources? Eisen's and Jamie's runs had clear distance markers on the ground (tape for Jamie and the football field for Eisen), were easy to time (just rewind the video), and show average runners (Rich Eisen and Jamie Hyneman might be the most average runners in history). All measurements considered, the final speed was roughly 12 feet/second, measured just over the first 5 and 10 yards to account for acceleration.
Condition Red Awareness (ready to fight): .9 seconds
Condition Orange Awareness (suspicious): 1.3 seconds
Condition Yellow Awareness (relaxed but aware): 1.9 seconds

Drawing your gun and firing is far more difficult under stress than when on the range. Even if you have already racked the slide and have a round chambered to shoot, the whole motion takes a lot of time. To assess the draw-time of real professionals under stress, I used two videos. In the first, a police officer draws a gun during a traffic stop, after a suspicious male pulls an object from his belt. In the second, a security guard pulls and fires on three robbers who burst through the doors and rush him. These clips not only give clear images of gun draw timing, but show it from different levels of awareness. The policeman is in "condition orange", fixating on an identified threat and generally prepared for a confrontation. The security guard is in "condition yellow", alert and aware on his job but overall at ease and with no specific threats in view. We can infer a "condition red" based on the time it takes for the two officers to draw their weapon when their hands are already on the gun.
The table below compares a) the charging attacker's distance and b) the draw speed of defenders at different states of awareness. The "Conditions" comprise a tactical awareness system codified by 20th Century gun icon Jeff Cooper (pioneer in stances, training, shooting, etc.). This article here gives a more detailed overview of the system. I have summarized key points below:

Just another day at the Reg
  • Condition White, aka Condition UChicago: Totally oblivious to any chance of danger. This is how you act when dozing in the Regenstein library during final's week.
  • Condition Yellow:  Your eyes are open and you are casually prepared for danger. This is how your average gun carrier or martial artist will walk around the street.
  • Condition Orange: You have identified a potential threat but have no reason to yet act aggressively. You are prepared for violence but not committed to it. This is how you act when someone asks to borrow your phone.
  • Condition Red: You knows that violence is coming. Your hands are ready to fight or already on your weapon. This is how you act when someone who just asked to borrow your phone gets angry and in your face.
With these conditions in mind, I have highlighted the earliest times that a defender in a certain state of awareness can act if attacked with a knife. In homage to the internet critics, I include both the hip-shot and stance-shot times (firing from the hip being substantially less accurate but faster).

Knife versus Gun Simulation
Time (t) Attacker: Distance
Condition Yellow Defender Condition Orange Defender Condition Red Defender
.09 seconds 1 foot

.17 seconds 2 feet

.26 seconds 3 feet

.35 seconds 4 feet

.43 seconds 5 feet

.52 seconds 6 feet

.61 seconds 7 feet

Shot from hip possible
.69 seconds 8 feet

.78 seconds 9 feet

.87 seconds 10 feet

.95 seconds 11 feet

Shot from stance possible
1.04 seconds 12 feet
Shot from hip possible
1.13 seconds 13 feet

1.21 seconds 14 feet

1.30 seconds 15 feet

1.39 seconds 16 feet
Shot from stance possible
1.47 seconds 17 feet Shot from hip possible

1.56 seconds 18 feet

1.65 seconds 19 feet

1.73 seconds 20 feet

1.82 seconds 21 feet Shot from stance possible

Remember that your average defender, whether police officer or civilian gun carrier, will recognize and identify a potential threat at condition orange. You can't walk around in a perpetual state of condition red combat readiness without scaring bystanders and probably getting in legal trouble. When a stranger starts an argument or gets too close, you can ready yourself to draw, but you really can't have your gun in hand and ready to fire. If they escalate from "Hey man what time is it?" to stabbing mode, you are going to be a step behind. But even if you were ready to draw (condition red), you would still be in danger at close range.

Here is a summary of the critical distances on the table:
  • Condition Yellow
    Fire from hip - 17 feet
    Fire from stance - 21 feet
  • Condition Orange
    Fire from hip - 12 feet
    Fire from stance - 16 feet
  • Condition Red
    Fire from hip - 7 feet
    Fire from stance - 11 feet
Conclusion: Unless you are in condition red and firing from the hip, any attacker within 10 feet is going to be fatal.

In the more common condition orange, our awareness level during a building altercation, the lethal distance of a knife extends to the 12-16 foot range (the same distance as covered by Jamie during the Mythbusters test). And all of those numbers assume that you are hitting on the first shot which, as will be shown, is extremely unlikely.

As our earlier conversation about stress suggests, it is hard to hit targets at close range when under pressure. But is there evidence to support our purely logical extrapolation? In a 2003 article (pdf) in Law and Order Magazine, Thomas Aveni analyzed thousands of NYPD police-involved shooting records. His goal was to separate the police academy myths from the street realities, and his findings were quite alarming. For our purposes, his most important conclusion concerned firearm accuracy at close range, or rather, their lack of accuracy.

A 100% accurate simulation
of a stressful attack
In a sample of 1,719 shootings between 1994 and 2000, 1,188 shootings occurred at a range of 0-2 yards (69% of the total). In such close range encounters, officers fired on average 5 shots, with some firing only 1 or 2, and others firing at least 8. The big surprise was not the number of close range encounters nor the number of shots fired. It was the accuracy of the trained and professional officers.

At 0-2 feet, officers only hit 38% of their shots. The dataset does not break down individual cases, so we can't know if some officers were firing three times and hitting once, firing twice and never hitting, or any other combination of hits and misses. To be conservative, we can assume that you would need to fire 3 shots to "guarantee" that 1 of them would hit.

This makes the knife situation even worse. Not only do you have to draw your weapon before the attacker reaches you, but you need to then squeeze off 3 shots under stress while a maniac is charging you, praying that your hits drop your target. Considering the adrenaline of your attacker, plus the locations of your hits, your shots might not even register.

Combining our revisit of Tueller's rule with the accuracy data of Aveni's article, we see that firearms are at a big disadvantage against close-range knives. Even stepping off the line of the attack, firing from the hip, and being in hyper-aware condition red are no guarantees of survival. Should you be lucky enough to draw your sidearm in time, you still are likely miss your first shot.
"Learn the best disarm techniques..."
These conclusions have pressing implications for firearm-carrying civilians and professionals. At close range, the gun is not going to reliably beat the knife. A much more consistent first line of defense is unarmed technique. Hand-to-hand knife disarms are dangerous and skill-intensive, but with practice and experience they can approach some measure of reliability. Obviously, the trick is to learn the best disarm techniques and not the ones that will get you killed. The other trick is to drill them under stress. Those unarmed techniques need not be the final defense. Instead, think of them as an initial shield and response to the knife before you disengage and draw a weapon. It takes less than a quarter of a second to bring your hands up in defense, which means you stand a chance against a knife even at around 2-3 feet.

"...and not the ones that will get you killed"
For police departments and academies, this means more emphasis on unarmed techniques and less emphasis on 25 foot range shooting. For civilians, this means equal training time on the range and on the mats. A handgun might be a great tool for self-defense, but in the close-range knife contest, it is just a false sense of security. The sword and bayonet may have been replaced in most arenas of modern violence, but in the realm of interpersonal criminal violence, remember not to rely on a gun in a knife fight.


  1. Good article, thanks for posting it.

  2. Glad that you enjoyed it. Some of the ideas definitely developed out of conversations I had with one of your students, Marc, during our time together in college.

  3. Very informative. I'm working on preparing an awareness drill and you gave me a lot of info. I'm always evaluating templates.

  4. zimmerman trial diverted attention from the 21 ft rule behind stand your ground laws. a citzen like a cop exercises self defense vs a skilled attacker armed only with basic streetfighting skills. rules of engagement must deal with when to draw if and when to warn and when to fire. without rules of engagrment precedent a successful self defense will often result in a death by guilty of murder one verdict. law and order without law is lawless order.

  5. zimmerman trial diverted attention from the 21 ft rule behind stand your ground laws. a citzen like a cop exercises self defense vs a skilled attacker armed only with basic streetfighting skills. rules of engagement must deal with when to draw if and when to warn and when to fire. without rules of engagrment precedent a successful self defense will often result in a death by guilty of murder one verdict. law and order without law is lawless order.

  6. zimmerman trial diverted attention from the 21 ft rule behind stand your ground laws. a citzen like a cop exercises self defense vs a skilled attacker armed only with basic streetfighting skills. rules of engagement must deal with when to draw if and when to warn and when to fire. without rules of engagrment precedent a successful self defense will often result in a death by guilty of murder one verdict. law and order without law is lawless order.

  7. Great post Sheridan, thanks for sharing the generally "unwritten rules." Of course, knives should only be used for outdoor sports/tactical use and self-defense. Be safe, everybody, and keep your blades sharp!

    DMT Sharpening Stones

  8. The author of this article COMPLETELY mischaracterizes the work of Tueller, and in so doing makes clear that he has little understanding of what Tueller was actually saying. Starting with his terminology. Tueller most certainly did NOT coin the term "21ft rule". First Tueller not only NEVER used the term, he has been adamant for decades that it is NOT a rule. He is quite clear that it is a DRILL, and is only to be used for training and illustrative purposes, NOT as a rule.
    Furthermore, the 21 ft part of theTueller drill is based exclusively on the starting condition where the subject has his weapon holstered. All other scenarios fall outside of the scope of the basic drill.
    Moreover, Tueller was also quite adamant that the drill could not be used in the reverse direction either, claiming that 1) outside of 21 ft, an officer was safe, and 2) that inside 21ft, an officer was justified in fearing for his life, and thus in using lethal force.
    In fact, no modification of the basic Tueller Drill, or the information it imparts, is necessary for those who truly understood what it was meant to illustrate in the first place.
    In fact, no new information was presented on this page that was not already addressed in Tueller's original work.