Solving the Impossible Math of Knife Attacks

There is a critical time discrepancy between the speed of attacks and the time it takes for the average human to process a threat in order to respond with the appropriate defensive actions. 

Let’s take a closer look:

To complete a knife thrust takes as little as .14 seconds.  It takes a little bit longer to complete the arc of a blunt force weapon like a baseball bat or crowbar.

It takes roughly double that amount of time for the average human to react to a visual stimulus at 0.25 seconds.  Now this average is for simple reaction times only…like pressing a button when a bulb lights up. 

It actually takes roughly .50 to initiate a defensive action under a visual threat stimulus.  That’s three and a half times longer than it takes for a knife thrust or a blunt force weapon to complete its arc!

But that’s not the end of it.  That half a second represents the initiation of a defensive action…not the completion of it!

And so this leaves us with a serious time discrepancy between speed of attack and speed of defense.  And these reactions times do not take into consideration discrimination and choice factors.  Threat or no threat.  Go or no go.  Or if you like, shoot or no shoot.

This may seem like an impossible task…but we have two outs.

One is that the average reaction time to a touch stimulus is .15 seconds…this brings us closer to bridging that gap between attack time and defense time.

This highlights the importance of sensitivity training in which I believe systems like JiuJitsu and wrestling are the kings of that domain.  Perhaps even Wing Chun can have a say in that conversation when done under the right context - as an example, while conducting a Chi Sao drill, one person can attempt to draw a concealed knife while the defender tracks and traps that intention.

The next out relates to instinct, heuristics, experience, recognition and intuition.  Now there are countless ways to compose meaningful drills in which these elements are developed but for now, let me talk about flow drills.

Under the predictable patterns, cadence and rhythm of flow drills we are not working reaction times at all.  And we are certainly not working decision-making.  These are misconceptions.  At best, under these conditions we are working mechanics.  Even at incredibly fast speeds, there is little to be gained as far as meaningful reaction times due to the flow drill’s predictability.

The secret lies in the random interjections.  The deviation from the standard or predictability of flow drills is where the magic can really happen.  These interjections can be framed to elicit specific or instinctive responses that aim to meet an objective.

For example, one training partner who is delegated to be the “feeder” can, at some random point, break the pattern to deliver an attack that diverges in some way from the cadence, pattern and predictability of the flow drill.  The other training partner must simply defend it…or fail to defend it.  Failure is a massively important element of flow drilling that we don’t often see especially given the nature of social media today where displaying mistakes and a failures can be seen as a sign of lacking expertise or mastery.

As an evolution to these random interjections, a coach can manufacture what I like to call “paired objectives” or “correlated constraints” — in this example, one person will have the objective of trapping or controlling the weapon bearing limb and the other person will simply need to recognize that attempt and free themselves somehow.

The architect of these paired objectives or correlated constraints, can elect to specify the actions and reactions of students.  In this case, person A breaks the pattern with a push followed immediately by a linear thrust to the face…person B must execute a simultaneous parry and cut, otherwise known as a gunting.

A well constructed flow drill can deliver moments where our intuition and instincts can come into play by keeping us in a heightened state of awareness and anticipation.  It can work on our recognition of attacks allowing us to see their precursors or tells.  Flow drills can be a heuristic model that gives us a repeatable method of discovery to find adequate solutions when optimal solutions may be difficult or impossible achieve based on things such as stress and time constraints.

It is important to also address the limitations of flow drills, even if we do them correctly.  For the development of mechanics or technique, flow drills have a very steep rate of diminishing returns and may not be the best platform for correction due to the highly dynamic framework.  Flow drills also do not represent the reality conditions of knife attacks nor do they represent the dynamics of self-defence conditions in the real world…they can only represent specific moments or elements in reality conditions.

While flow drills can be simple, they are often too complex requiring more time to reach base memorization.  They are inefficient in that for two individuals to gain the benefits I proposed, they must first learn the rules and standards of the drill itself.   It’s like giving seeds to someone who is hungry.  It doesn’t immediately solve their problems.

Overall, flow drills, when done correctly can be an incredible tool that can help us manage and bridge the discrepancy between attack time and defense with elements of critical decision making under extreme time constraints.  However, it is only one piece of the puzzle.  It must be intelligently paired with other training modalities and protocols in a way that is congruent with the objectives of the client or student.