One of the most commonly suggested tactics regarding defending against a knife attack is to gain control of the weapon and retain that control. That makes sense and is in fact sound advice. It’s a common knife defense strategy for many martial arts. But that strategy does not reveal the complexity and reality of being empty handed and defending against someone with a knife. It’s somewhat like being advised to avoid hitting the ground at high velocity when you find yourself thrown out of a plane without a parachute. Good advice nonetheless but hardly provides a suitable solution.
Getting hold of the hand or arm holding the knife is much easier said than done against a knife attack. It presumes that the attacker isn’t trained to use that weapon efficiently or he will allow you to get hold of his weapon hand. Never assume that the attack doesn’t know what he’s doing. Making such a false assumption against a knife attacker is fatal.
Someone trained to use a knife already knows that the defender will try to control the knife. If he’s properly trained and highly skilled, he may even use the hand holding the weapon as bait to cause the attacker to lunge or commit to grabbing it, leading him to a trap that ends with multiple slashes and stabs on the defender. Even the untrained know that his weapon gives him the advantage over the empty handed and you will literally have to take the knife out of his cold and dead finger to get full and final control of the weapon. Just by watching a few videos of prison stabbings will make one realize that the rapid and repeated thrusts to the head and neck by the average inmate will be difficult to stop if the strategy is to simply grab the weapon hand and control it.
I’ve seen a number of videos of realistic knife defense training done by different systems that don’t practice using the knife realistically. The result is almost the same every time; the defender tries to grab the weapon hand right away and apply a lock to disarm or to restrain the attacker. The defender gets cuts and stabbed as the single-mindedly focuses on going for the weapon, mesmerized by the thought of controlling the weapon.
One common misconception is that stab or slash to the forearm is an acceptable and bearable injury in a knife attack. Some even advocate leading with one forearm out as a “shield”, allowing the limb to be attacked as the defender closes the gap, and attempt to grapple with the attacker. This is a dangerous assumption. Even a short reflexive slash with a small folding knife will create large and gaping wounds, on a forearm or on anything that’s in the way of the edge. Paul Vunak demonstrated this in one of his videos, where he slashed a hanging slab of beef with a knife. The resulting deep cuts should be enough to convince anyone that it’s not a good idea to lead with a limb.
I do respect those who try to go out of the box, for practicing their system outside of its usual set forms and dealing with realistic knife attacks, but the problem is more strategic rather than technical. Controlling the weapon indeed works but only after you’ve made it possible to get hold of it without getting yourself badly cut and stabbed while doing so. Chasing after the knife in the hands of someone trained to use it won’t work because the knife will always be in motion. No one attacks and leaves the knife out in midair, for the defender to deftly grab and apply a wrist lock on to. In reality the knife will be zipping from one slash and stab to another, too fast for the defender to track and follow and if he tried to do that, he will have already been stabbed and cut to shreds without actually getting full control of the weapon.
The attacker’s other hand is not going to be motionless and paralyzed either; it will be grabbing the defender when the opportunity presents itself, parrying defenses in the path of the weapon or even applying hand or elbow strikes when the opportunity presents itself. When blocked or deflected, the trained knife attacker will redirect his attack immediately, either moving from a stab to slash or vice versa, with his other hand clearing obstacles for the weapon to finally land on its target. This reality of knife attack will only dawn on most martial artists after they themselves learn to use the knife effectively.
Most people will argue that it’s illegal to carry a knife in their city or country, so training to use one is impractical. That’s a valid point, but in my opinion one that only considers half of the benefits of knife training. Learning to use the weapon teaches the weapon’s capabilities from the point of view of the user and that insight will help immensely with forming a realistic knife defense strategy.