I'm in the closing stages of finalising book #1 on the science behind fighting techniques. The introduction leads with Gracie and Gracie's (Brazilian Jiu-Jitsu: Theory and Technique) explanation of black belts as being fully qualified teachers who are expected to know why a technique works in addition to knowing how to perform the technique.
My final chapter asks how Gracie and Gracie operationalise their expectation of black belts. They don't do it through their grading system (if they do it at all) because they explain how the Brazilian jiu-jitsu grading system is characterised by its extreme informality.
I reflected on the grading system that Shihan Jan de Jong OAM 9th Dan developed and came to appreciate that (a) de Jong shared Gracie and Gracie's expectation of black belts, and (b) uniquely operationalised that expectation in his 1st Kyu and Dan grading system. There are numerous gradings that examine a candidate's understanding of why a technique works and their teaching ability, however, de Jong was hamstrung in this respect because the body of knowledge associated with why a technique works is largely nonexistent. My book is written in an attempt to begin to fill the void that is the body of knowledge associated with why a technique works.
I've begun to research how other schools produce their teachers. For the most part, it is that a black belt (a) knows how to perform techniques, and (b) that knowledge and that grading qualifies them to be a teacher.
How does your school produce teachers?