Self-defence against knife attacks: evidence-based approach

In this article I present the results of a detailed analysis of over 200 real knife attacks caught on surveillance cameras.

This research was conducted in 2016 and updated several times since then.

At the time, I wanted to understand the dynamics of real-life situations and how an attacker was most likely going to use his weapon.

This, I thought, was necessary in order to adopt realistic methods of self-defence against knife attacks.

Back then, the data was readily available on Youtube for anyone who was willing to carry out the (tedious) video analysis of hundreds of real-life examples of knife attacks.

No one had done it so I decided to give it a go...

Back in 2016, my initial idea was to keep the whole collection of videos accessible so other people could verify my results and investigate the topic further.

Unfortunately, over the years Youtube has cracked down on violent videos. My channel was closed and the collection lost.

The results of my investigation are still valid and have been updated through the years.

This article is structured in three parts:

• Part 1 presents the keys points of the analysis of 200+ knife attacks (video material)
• Part 2 ("How to survive a knife attack") addresses commonly-debated issues such as awareness, avoidance ("running away"), compliance, the use of weapons (incl. improvised weapons) in the context of knife attacks
• Part 3 ("Bare Hand Techniques against Knife") covers a variety empty-hand techniques, from different schools of thought, in view of what's discussed in the first two sections

*This a substantial article which took months of painstaking and meticulous work, so I hope you'll enjoy reading it .

PART 1

KNIFE ATTACKS: AN ANALYTICAL STUDY 

While the sample might have a number of flaws, the results have stood the test of time and are easily verifiable.

As of 2023, the evidence gathered so far suggests that human behaviour is quite consistent in these situations.

Note:
Only situations when the victim is attacked (i.e. physically assaulted) are considered in this article.

Simple threats with no assault (sometimes mislabelled "static attacks") were not considered because the main interest was the dynamics of an actual attack.

71.1% of knife attacks are led with the empty hand

The fact that, during a knife attack, aggressors usually lead with their free hand, while keeping the knife close to their side, was first pointed out in 1988 by Don Pentecost in his contentious book Put'em down, take'em out! knife fighting from Folsom prison.

Back in the 80ies, Pentecost simply and brutally shattered a number of popular myths and preconceived ideas about the use of knives in real life situations (see a review of the book on Wim Demeere's blog).

Most commonly (71.1% of the time) aggressors will lead the attack with their empty hand, effectively shielding the knife.

As Pentecost also clearly stated, the empty hand is not a dead, "paralyzed", hand and attackers will use it to strike or, more commonly, to grab the victim.

Indeed, when aggressors lead with their free hand, 80% of the time they will also use it to latch on the victim.

This use of the empty hand (also known as 'leveraging arm') greatly changes the dynamic of the fight. Particularly because your first reaction, as a victim, will be conditioned by the movement of the aggressor's empty hand (more on that in Part 3).

But the prime lesson though is that most of what is taught in the Martial Arts and RBSD industry (i.e. attacker leads with the knife, no grabbing, no forward pressure) doesn't apply to the vast majority (70% +) of real life knife attacks.

Most knife attacks are ambushes, not duels

For the same reasons bad guys will use a force multiplier such as a knife -i.e. they don't want a fair fight but an easy prey- they'll make a surprise attack on you from a 'concealed' position or with 'concealed' intentions.

And you probably won't see it coming.

The aggressor won't threaten the victim. Instead, he will keep his weapon concealed until it is time to strike.

“Victims who survived a violent confrontation against a knife-wielding assailant consistently reported that they were completely unaware of the existence of the weapon until after they had suffered stab or slash wounds. In essence, these survivors of edged weapon attacks state that they believed they were engaged in some sort of fist fight; only later, after sustaining injuries, did they realize that the assailant was armed.” Imi Lichtenfeld (Krav Maga founder)

In 80% of the cases I've analysed, the knife is kept hidden until the very last moment. That is until the attack is launched.

Aggressors will try to distract the victim and wait for a good window of opportunity to strike and won't hesitate to attack the victim from the back.

Situations with multiple attackers seem less common with only 11.4% of the incidents I've reviewed.

In a typical way, the victim is 1) distracted, 2) cornered, and 3) the attack is launched at close quarters.

70.6% of knife attacks are launched within 3 feet of the victim

Knives are short range weapons, so it doesn't come as a surprise that 70.6% of knife attacks start at conversation range.

It's important, though, to stress that "within 3 feet" really means "at arm-length or less".

This leaves you with very little space (and time) to react!

Such a small 'reactionary gap' means that it's almost impossible to stop the first stab if you're not expecting it.

This is why it is so important to maintain distance and keep control of the space when you're in a confrontation.

As aggressors so often lead with their free hand (usually the left one), victims end up being stabbed in the neck, like in the video above, or to the chest on their left side (where the heart is located!).

Knife attacks are fast and furious

Another consequence of such close-range attacks is that victims tend to fall as they move backwards trying to escape their aggressor.

This is the case in 55% of the incidents I have analysed.

This way of charging a victim, as seen in the video above, is known as a "prison yard rush" (or "prison knife rush"). It was made notorious in the Martial Arts industry by Don Pentecost in 1988.

In his then-contentious book, Pentecost further points out that someone who is attacking you with a knife is trying to kill you.

They won't hold back, they won't hesitate.

They will go after you like mad dogs.

"Research tells us someone willing and ready to carve you up like a thanksgiving turkey is far different than someone with a gun [...]" Hank Hayes (Knife Defence 101)

What can be seen is the aggressor going full on with ruthless determination in an attempt to overwhelm his victim and cause maximum damages as quickly as possible by whatever means necessary.

Knife attacks don't last long

Indeed, the average incident time (i.e. arithmetic mean) for knife attacks, from the moment the attack is launched to the moment it stops, is 23 seconds.

"The time frame of a knife attack is usually very short - it is often over in a matter of seconds" Don Pentecost

The median time is 14 seconds which means that half the attacks last 14 seconds or less.

But 80% of all attacks last less than 32 seconds:

The graph shows a sharp increase in numbers up to 23 seconds indicating that most attacks (70%) last 23 seconds or less.

After that point, the curve starts to flatten and reaches 90% at 59 seconds.

It's interesting to note that, although it takes 9 seconds for a 10% increase to 80%, it then takes 27 seconds to complete another 10% and reach 90%.

What this means is that if a knife attack lasts 23 seconds, you have a fair bit of chance that it will go on only 9 more seconds. But once a knife attack reaches the 32 seconds mark, the same "fair bit of chance" may requires an extra 27 seconds.

In other words, if a knife attack goes on for longer than 32 seconds, it is more likely to last a lot longer.

Did you notice how the curve seems to go up again around 45 seconds instead of plateauing as expected?

Let's visualise the data differently,

The following graph shows the number of knife attacks plotted against time. To make it clearer, I just show the trendline:

There's a peak in the number of attacks around 7 seconds with 25.2% of all attacks lasting between 5 and 10 seconds, and half of all attacks lasting 14 seconds or less.

Now, what that tipping point seems to indicate is that if you can hold your ground for 7 seconds during an attack, the aggressor is more likely to give up.

The fear of being caught is likely to be an important factor that keeps knife attacks very short.

Obviously, the longer an attack is carried, the more likely someone -including the police- will intervene.

In that regard, it is interesting to note that 55.9% of all attacks are stopped by the intervention of a third party.

But here is the fascinating part,

From the 7 seconds mark, the number of attacks goes down sharply to reach a minimum at about 45 seconds and then goes up again.

What the graph shows is that there's a second tipping point around 45 seconds after which a knife attack will tend to go on much longer. Most commonly an extra 14 seconds. More than half of the "over-45-seconds" attacks last between 53 and 66 seconds.

Although it is hard to infer any solid evidence from such a small number of  cases, it seems that third party intervention occurrences are much lower in the 45-seconds + group than in general.

In other words, these attacks lasted longer because no one intervened.

Unsurprisingly, attacks by 'psycho lovers' -who don't care much about being caught- seem to be concentrated in this group as well.

Although the average duration of a knife attack is 23 seconds, it is important to keep things in perspective.

In that short amount time, the average attacker will stab you at a rate of 5 to 7 times every 5 seconds!

Knife attacks are more often performed with quick, short, repetitive stabs at different angles

Commonly, there will be a first wave of stabs during which the attacker, taking advantage of the surprise, will land between 5 and 10 stabs. Then, as the victim fights back trying to escape, the stabs will be spaced-out.

The more you get cut or stab, the more chances a vital organ, such as the heart, or a major blood vessel, such as the carotid artery (neck), will be hit which would result in a quick death.

Things can go really fast. In one video, the victim totally collapses less than 40 seconds after being stabbed twice!

Sure, many people have survived a greater number of cuts and stabs. But the unavoidable truth is that you only need one to die!

This is an important point because most attacks are not a 'single straight thrust' (i.e. bayonet thrust type of motion) or a 'wide sweeping stroke' (i.e. slash).

Knife attacks are predominantly executed with quick, short, repetitive stabs at different angles (e.g. switching from low, upward, stabs to the chest, to high, downward, stabs to the neck).

Also known as the "sewing machine" and "prison shanking", short rapid stabs are very difficult to stop because there is not much time and not much space to 'deflect-and-redirect' the attack or 'block-and-strike'.

The majority of attacks are carried out using a regular grip (58.8%) but the reverse grip (also known as "icepick grip") is, at 29.9%, more frequent than commonly thought.

In a small number of cases, around 6%, the aggressor changes his grip during the assault, moving from regular to reverse or vice versa.

It's worth noting that I've not seen any case of hand-swap (i.e. knife being moved from one hand to the other).

What have we learned?

In this first part, we've seen that knife attacks are most commonly ambushes, launched at short range (within 3 feet of the victim).

They are extremely violent; carried with speed and determination within a very short span of time (i.e. they don't last long).

Attackers will lead with their free hand, effectively shielding the knife, and will stab the victim repetitively with quick short thrusts at different angles.

Attackers frequently grab and push the victim who quite often will fall to the ground.

In other words:

1. you will be taken by surprise and you will be overwhelmed by fear and aggression
2. you won't see the blade before the attack is launched
3. you very likely won't be able to run away and avoid the attack
4. you will have very little time and space to react and deploy a counter-attack
5. you probably won't be able to stop the first stab(s) so, yes, you will be you will be cut and stabbed a number of times but you might not even realise you've been stabbed (which is why you should always check yourself for wounds after a physical confrontation)
6. you probably won't have time to draw your own weapon (gun, knife, kubotan keychain, pepper spray, etc); at least not before being stabbed a couple of times
7. you will be likely moving backwards, your balance will be compromised, and you'll probably fall to the ground
8. your movements will be restricted, your fine motor skills will be gone, you won't able to access the knife bearing arm easily
9. any technique that is based on smooth arm deflection and manipulation has very little chance to work
10. any technique that rests on the assumption of a single straight thrust ('full-stop one-step zombie attack') or a wide sweeping slash has very little chance to work

These results should definitely inform our training methods and I will expand on that point in Part 3: "Knife Defence - Empty-hand Techniques".

But the nagging question at this point is "how do people survive knife attacks then?"

Part 2: "Surviving a knife attack" >

_________________
By Patrice Bonnafoux
I'm a self-defence instructor based in south London. I was first introduced to Krav Maga in 2001 while in the military and I have been teaching for over a decade now.