How to block a knife attack

As you know, I’m working on a book on self-defense against the knife. By the way, I’m still looking for people who want to share their story about that (anonymous if they prefer.)

What often comes up in my research is that people fall victim to some misconceptions and myths about the techniques you can use when somebody tries to stab you with a blade. One of these is that you should try to “block the knife attack”. I’m not claiming it’s impossible because I know people who’ve done just that but I am going to say that there are good and bad ways of going about it. Not to put a fine point (hahaha) on it, do you want to know how to block a knife attack? Not like this guy did..

how to block a knife attack

How to block a knife attack? Not like this...


The irony of this picture is of course the tattoo on his chest. Seems like somebody wanted to test that theory…

Back on track.

There are numerous ways of defending against a knife attack and they all have their value. Some are better than others. Some are worthless in my opinion. And then there’s everything in between. That said, however “bad” you may judge a technique to be, there is only one factor that determines its worth in the end: did it work or not? If it didn’t, then either the technique sucks, you did it wrong or you were just out of luck.

If it did, then you need to figure out why it worked. Because it is easy to delude yourself into thinking that you did everything right. But the truth of the matter is that it is difficult to know for sure which specific factor of all those involved was the one that determined that positive result.

  • Was it your speed?
  • Was it your strength?
  • Was it the specific angle your arm moved in?
  • Was the attacker slower than you?
  • Did he give away his intent to attack right before he did so?
  • All of the above?
  • None of the above?

Who knows? Who can say which point of this list was the one that saved the day?

To compound the problems, two more things:

  • Under intense adrenal stress, the human brain can distort reality. Your memory of events is not necessarily accurate. It might be, but you might be totally off too. As in, claiming you did the opposite of what actually happened. For more information on this, I recommend you read On Combat and On Killing. Both books give in depth information on this topic (and much more)
  • If it was captured on video, the quality of the video determines the information you get. The angle at which the footage was taken, moving or stationary camera, lighting, etc. all play a huge roll in determining what actually happened instead of what it looks like at first glance.


Case in point 1:

A friend of mine is a LEO and he does lots of scenario training. What follows afterwards is a debriefing and analysis of what happened, what went wrong, what needs to be improved, and so on. It is not uncommon in those debriefings that people claim the total opposite happened of what another guy says, despite the fact that they were standing right there together, seeing and experiencing the exact same thing.

The same happens (perhaps even more so) in debriefings of actual life and death situations.


Case in point 2:

Take a look at this video:

Looking at it from this angle, it looks like the officer in the back murders that man in cold blood. The “victim” is complying with the order of putting the gun down and still gets shot dead. Right?


Look again.

As the man bends over to put the rifle down, he reaches behind his back to draw a handgun. The officer spots it, shout’s “Gun!” and saves his partner’s life.

In case you missed it, the gun is in the red circle in this picture.

How not to block a knife attack

Now this is only a training video but it clearly demonstrates my point: analyzing information on a video is difficult. It takes a lot of practice and even then, it’s still easy to miss things. Despite that, we all (me included) do this all the time. The important thing is to understand the limits of what you can learn from videos: sometimes (perhaps often), things aren’t what they seem.

It’s for exactly this reason that Youtube is filled with stupid comments. Or why people criticize police officers, soldiers and other first responders when they see video footage. They think they know what happened but they don’t. Let me rephrase that: often, not always but very often, they are just dead wrong.


Let’s get back to dealing with a knife attack.

As I pointed out here above, when you defend yourself successfully, it’s hard to know which factor was the one that made sure you didn’t get stabbed. Which is why you want to have as many  factors as possible lined up to improve your odds of success. If one of them fails, you still have the others.

I only really learned this when I started practicing tai chi chuan because in my style, we only do three things against any attack:

  • Move the attack away from the target.
  • Move the target out of the way of the attack.
  • Use footwork to get to a safer position.

Preferably, we use all three at the same time. Though circumstances might dictate emphasizing one of these three over the others.

When you block a knife attack, settings things up so you have as many of those factors working for you is crucial. Because unlike in an unarmed fight, a blade can kill, cripple or incapacitate you with even a light touch. So it is crucial you try to avoid getting hit. Then it only makes sense you don’t count on just one thing to keep you safe. Instead, you try to make sure you are holding nothing but aces in your hand.

It’s with that in mind that I analyze techniques. I look for those who offer the best bang for buck and aren’t depending on just one factor to make them work. Because if something goes wrong with that one, you’re in trouble.


Case in point:

Take a look at this video of a karate defense against a stabbing attack to the stomach.

Before I comment, first this: I don’t know this teacher and don’t want to come across as overly critical. What I am going to do is try and point out how what I wrote here applies to this video. With that in mind, here’s what I see:

  • He steps straight back when the attack begins, breaking the distance.
  • He blocks/sweeps down with his lead arm, grabs the wrist with his back hand and delivers a backfist to the neck.

In this video, you clearly see he didn’t get stabbed so it worked. Can he do it in real life? Has he done so? Can you do it like that? I have no idea. That’s also not the point right now.

Let’s look at some other factors:

  • He stays very close to the attacker. If the block fails, he’s in real danger of not being able to step back in time to avoid another strike.
  • He stays on the line of attack. The knife is still in front of him, so is his attacker. This is dangerous.
  • He doesn’t divert the knife away from the target. Look at where the attacker has the knife pointing right after the block and grab: straight at his stomach. So if the block fails, there’s a clear path to his stomach.
  • The attacker’s arm is fully straight before the block makes contact. This means the attack is finished before the defender does anything to stop it.

It’s this last point that is critical: by the time the defender’s blocking arm slaps the knife-arm down, the attack is already over. In combination with all the other points I mentioned, this brings me to one conclusion:

The only thing that saved the defender from getting stabbed was the footwork.

Everything else he did failed to keep him safe. Had he not stepped back, had the attacker lunged a bit more, he would have eaten the blade in the gut.


That’s what I mean when I said you need to know why something works: the reasons you think it does and the actual reason might be totally different.

To be clear: is this technique worthless? No, not in my opinion. I would call it an “Oh Shit!” technique, which is a technique for situations in which you are behind the curve or for some other reason can’t do something more effective. There are some things you could do to make it better though. But to do that, you need to analyze it in depth, in the way I described here.

There’s a lot more to it than this but I just wanted to give the basic concept so you can use it for your own training. Special thanks to Loren for posting the picture on his Facebook page, which inspired this post. :-)



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  1. Interesting post Wim as usual.

    One thing I will add about a good knife defence is that it should not only stop the first stab, but also deny the attacker the ability to try a second, third, fourth and so on.

    Some form of latching onto the knife bearing arm is important. How you want to exactly go about that is up to you. Your points about moving off the line of attack is also bang on. What you do from there is also up to you. Stopping the stab (and further stabs) is the first but most critical step.

    Looking forward to the book.

    • Thanks Adam, glad to hear you enjoyed the post.
      The trick with having all those factors aligned is that when combined, they take care of that problem. Whether it is done by grabbing the arm or something else depends on the style/person/circumstances IMO.

  2. A thought i had: something I came up with to explain the way I learned techniques is that there layers built in so that when you screw up you still have something. I learned to angle off and block/check essentially everything. Of course done perfectly any of those three are enough but who can rely on being perfect? When practiced at speed if you get any two of those you are doing prety well and pretty safe and are probably okay with one, as long as it’s done well. So that the point of training to do things riht isn’t that you will be able to execute that perfectly at speed against a real threat but rather that you have inherent redundancies so that even your mistakesnare successful. But then what do I know as I’ve never had to defend against a knife attack (a knife threat yes, attack no).

    • Travis,
      You will find that concept in virtually all the traditional arts that didn’t get watered down and also in some of the modern combatives systems. It marks the difference between integrated systems on the one hand and sports martial arts or MacDojo-type styles.

      • Yeah, I see the concept but rarely hear it articulated. Mileage may vary but for me the ‘why this way’ was something I had to work out on my own.

  3. Hi,

    I was curious about that video of the police shooting. One of my friends sent it to me a while ago and asked what I thought. I told her that I thought it was a training video for various reasons but I wasn’t 100% sure. How do you know that it is a training video?



  4. Whenever I see ridiculous knife defenses like the one in the video, I always think to myself “now what.” In this situation the guy just got backhanded to the face or maybe the neck if the defender is lucky. In either case no body weight was used in the strike so the attacker just got a light to medium strike, which is in no way debilitating. He still has the knife. He still is able to fight. The only difference is now he is pissed, and now he knows his opponent knows how to fight. I hope the karate guy is a fast runner because that is what he should be doing right about now.

    • I have to disagree in part with that Sean. The backfist was targeting the side of the neck (and it did land there). There are arteries and nerve clusters there that can yield instant knock outs. So it’s not impossible to use. That said, if the strike missed or wasn’t hard enough, the defender would be in a scenario just like you described.

    • With all due respect Sean, if you go around maiming your training partners, you soon won’t have any.

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