Explaining or Training? Part 2

So what purpose do explanations serve and to what extent should you rely on them?
As a teacher of a psycho-physical discipline my rule on explanations is just enough to improve performance.  Anything more is simply too much talking and not enough work.  Enter the “Karate Nerds.”
The Karate Nerds are the guys who want to know, intellectually, all about the martial arts so they can have lengthy discussions and debates about the finer points of the art.  They usually don’t even seem like they want to practice, just talk about it.  The Karate Nerds make the mistake of thinking that if they can understand what makes the art then they have mastered it.
This post facto analysis assumes that if you can reduce a work of art, martial or otherwise, to its constituent parts then you have mastered it  It is akin to analyzing all the notes in a Chopin piano concerto and then believing you can create one just as good by knowing them.   In the end being a karate nerd is just an appreciation of the creative expression of someone else while fooling yourself into believing you can do it also.
Explanations should exist to further physical skill; you should not have a physical art so you can create volumes of explanations.  As soon as there becomes a secret code language of the art physical training devolves into mental exercise.
Here is an example of the correct amount of explanation in Systema.  “Keep your Form, don’t bend over.”  This concise advice is easy enough to understand and apply immediately while continuing to train.  In fact, most explanations can be made in the course of moving.
Explanation is an integral part of training but it should be applied judiciously.  Always ask yourself, “Are my physical skills improving, or those of my students, as a result of this explanation or am I wasting valuable training time”?