You may also have heard this drill or demonstration referred to as the “21 foot rule” based on the typical distance covered. The “Rule” implying that at greater distances you are safe – lessor, you are in danger. You might also have heard it described as a distance at which someone who has a knife may be shot should they move to attack you. There is more to it than a quick formula to apply as you visually estimate and mentally measure twenty-one feet from where you are standing. It’s not that simple, and not that black and white.

While a sergeant with the Salt Lake City PD, Dennis Tueller developed a drill that bears his name to demonstrate just how fast things happen in a dynamic situation. The premise: a bad guy, armed with a knife (or even unarmed), can cover 20+ feet before an officer can draw and fire their duty firearm. The problem: officers and decent citizens are allowing bad guys to get too close, or not paying enough attention – and either can be attacked and seriously injured by a motivated bad guy before they can access and use the firearm they carry to defend themselves.

To demonstrate this in a training environment, you typically use three people. One is the bad guy, another the armed good guy, and the third operates the timer. After each demonstration, they all switch roles – that way, all three will experience the demonstration from each of the three perspectives. Safety procedures must be in place – rubber knives, plastic replica guns, and the understanding this is a demonstration, and not an actual attack – this should be repeated often, those involved often take drill this very seriously, and we don’t want any injuries, or bad feelings.

The timer may use verbal signals, a whistle and a stopwatch, or an audible timer set to sound the start, and then sound again one and one half seconds later. The good and bad guys are set to stand about twenty feet apart. The time on one and one-half seconds is based on the average time it takes a typically competently trained person to draw and fire a pistol, some times may be faster, some – like those carrying concealed, may be longer. The distance – most people can cover twenty feet (plus or minus a foot or two) in that same 1.5 second time frame.

Both of those involved know what will occur, so they can be at their peak level of mental preparedness, but neither knows when it will begin. Any hesitation will be minimal – there will be no element of surprise to benefit either party. At the signal, the bad guy moves as fast as possible to attack the good guy with the rubber knife. The good guy will draw their firearm and defend themselves against the attack. At the second beep of the timer, or verbal command from the timer, both will stop their actions and assess how far they were able to get.

So what will happen? In the years Sgt. Tueller did this, and with many others – including when I have done this in training – very similar results were common. The armed good guy, if they are able to draw and fire (saying “Bang”), it is at best – happening at the same time the rubber knife is contacting them. The best results that can be expected – a tie. Understand, in this case a tie means both of you end up going to the hospital or dying. Sorry, but a “tie” is just not acceptable. To go home after a deadly force situation, you must win.

When reading about this drill on paper, we nod in understanding, and agree that we see the point. But, only in going through the actions in person is this severe reality quickly and completely grasped and fully absorbed by the role players performing the drill. Switching between the roles, they experience for themselves how little time it takes to reach and hurt someone who has a holstered gun, and how long it takes to draw that gun when someone is running toward you at full speed with the intent to do you harm.

The intent and purpose behind this training demonstration is to emphasize that when you are dealing with a potentially violent attacker – you need to remain very alert and probably hyper vigilant. Don’t take the drill and the results you might experience in a training session as a hard and fast unbreakable rule that is unable to be changed. Paying attention and thinking about your options give you more chances to not only win what looks to be a losing hand, but win decisively.

The drill is most often conducted with the good guy remaining stationary. Should the good guy start moving backwards – the distance is increased, giving more time to draw. Or, should the good guy suddenly move to the side and take several steps away from the line of travel of the attack as the bad guy gets close, the bad guy must slow, change direction, and then begin to move toward the good guy once again – all of which takes additional time.

Creating additional space between you, stepping around a barrier or putting an obstacle in the attackers path, or sensing danger is near and placing you hand on your holstered gun to reduce your draw time, drawing simultaneously as you move away or step to one side – accomplishing both at once, or even throwing something to distract the bad guy and delay him enough to give you a slight advantage – any or all of these may be possible.

Remember that distance is time. The further away you are, the longer it will take for the bad guy to get there. The more obstacles between you, the more time you will have. The sooner you notice a suspicious person approaching, the more time you have to process and react to their appearance or actions. These are the real lessons to learn from this training drill.

Stand in the center of the room. Lift your arms up, and move them to the sides. Friends, family, those you know and trust are the only ones you should allow in the circle of “arms-length,” otherwise a quick punch can easily be delivered within this distance. Next, motion through a kick, not just the length of your raised leg, but the length of a kick when the hips shift and the foot is driven to the side – this is probably closer to five or six feet – anyone within this distance can drive a powerfully driven foot to knock you to the ground. Consider the distance needed to hit you with a striking weapon – generally between the arms-length and kick distance.

Next, consider how quickly can someone take two rapid steps and be within any or all of these danger zones? The reality is that unless you train regularly in hand-to-hand techniques, you would probably not be able to react fast enough to defend yourself from the first, and maybe the second strike. An unexpected attack at these distances would be very hard to prevent.

I explain this not to frighten you, instead I want you to remember this the next time you see someone who is a potential threat, or becoming openly threatening to you. Don’t underestimate how quickly an attack can occur, and how little time you will have to react when someone starts to move toward you. Start now, thinking and planning in advance what you might do. Consider what tools you may have, and what you can do to create distance or barriers to slow them down? Plan now, to be ready when you need to be.