I think the really crucial thing is how long the instructor has been teaching, personally. A friend of mine is 2nd dahn in Kuk Sool (soon to take his first test for 3rd dahn), and the kinds of mistakes he makes in teaching aren't because he doesn't know the material well enough, but because he doesn't have as much experience in pedagogy. It's the same in most any discipline. The chief instructor is a 5th dahn, and the reason he's an amazing teacher is because he's been doing this so long, and he's watched hundreds of students make the same mistakes I do. When he sees me do something wrong, he has a whole arsenal of ways to correct it, and if I don't respond to one way, he can try it a different way. First post, by the way. Hi everybody.