Have you ever heard of Goodhart’s Law? I had not until a few months ago, when I heard it explained on Tim Ferriss’ podcast, The Tim Ferriss Show. The concept made such an impact on me that I made a note of it, something I rarely do.

Coincidentally, a colleague of mine posted the above graphic (from Sketchplanations) on their podcast’s Instagram page, BJJ Mental Models, and I decided to expand on this for my own students.

Goodhart’s law discusses the natural human tendancy to meet the standard being measured. As the graphic demonstrates, if you say you will be measuring (or perhaps paying a bonus on) the number of nails made, the subject will make as many nails as they possibly can with a given amount of material. Conversely, if you are measuring success by the weight of the nails, then it would be easier for the subject to meet the measure by making a few, very large nails. Focused on the measure, the subject has misunderstood that you actually wanted a specific type of nail.

This means that if you do not set clear expectations and standards then people will simply meet what they are being measured on, interpreting that measure as the abstract target for success. In one or both of the examples above, the results are unlikely to have been what the boss wanted.

For martial arts this law can be easy to see.

The people “making oddly sized nails” are called “belt chasers.” That is, a person who is simply seeking belts because they represent progression in the form of a tangible measurement system. Thus the “belt chaser” believes that simply receiving a belt is a measurement of their skill, and therefore they expect that they have achieved an understanding of concept and application by merely demonstrating the techniques required for that belt level.

The truth is, it is not always about the belts but rather an individual’s ability to improve and progress. Some people may take longer than others, especially when there are clear and specific standards in place.

My approach to belts and promotions is that, if a person is simply seeking the next rank but lacks the nuanced skill, I would hold them back; because they have failed to understand what is actually being measured. This often means they have met the minimums, performing the techniques, but have failed to show what is actually expected, conceptual understanding.

This individual may be distaught when they are held back, as they will say “I have met the minumums thus I deserve to be tested/promoted.” They are falling prey to Goodhart’s Law. They are focusing on what’s on paper, a list of techniques at this belt level, what is being measured, rather than what was actually expected of them to learn.

For Krav Maga, the goal is making people capable of defending themselves, and a belt on its own does not do that; you need the skill, the concepts, and the ability to apply both. In the world of Krav Maga, simply being a “belt factory” is far more catastrophic than for other styles, as our focus is specifically self defense and not sport in any way.

This means that if you are a school that would rather promote someone because they are belt chaser, and you want to keep them as a customer, rather than delaying until they are actually where they should be, then you will be doing your students a great disservice; they may not be able to defend themselves as well as they think they can.

So, if you are a belt chaser, stop and think about the fact that you may be failing to understand what is actually being measured. While the tests and belts are literally about measurements and standards, a good Krav Maga school (or any martial arts for that matter), while be looking for far more than just techniques before they consider someone ready for a test or promotion.

Consider this, might your school be assessing other qualities like:

  • Physical Skills improvement
  • Mental Strength
  • Verbal Skills
  • Social Skills
  • Dedication to the school or sport

While these may not seem like things that should be measured when it comes to Krav Maga or martial arts, the real goal is self improvement; physically, mentally, and spiritually.

If you simply seek the belt, then perhaps you are not in fact ready and you are falling into the black hole that is Goodhart’s Law.