It is often said in kendo that you can recognise the teacher from the student’s bad habits. I believe that there is a lot of truth in this statement. It is therefore essential that new kendoka do their homework in selecting an instructor and more essential that those of us that teach do not get complacent and sloppy.
Kendo teachers should ensure that they spend as much time as possible learning from more senior sensei and treat every practise with students as if it were a grading examination or an enbu. That is not to say that they should not get hit, but should ensure that even when they give an opportunity, concentration, spirit and zanshin is not lost. It is too easy to let concentration lapse in keiko with a less experienced player and if an instructor just walks away after an attack or does not maintain an attacking spirit, it is likely that a student will think it is the correct way to behave. “Kendo begins and ends with rei” and reigi entails treating seniors and juniors with equal respect.
For students in search of a teacher, grade is of course a good indication of an instructor’s kendo ability and knowledge. Whether or not their coaching style works for you is up to you to decide. Unfortunately it is hard to make that decision without some kendo experience and points of reference. Another thing to remember is that an instructor who is seven or eight dan grades above you might be the ideal person to demonstrate or describe what you should be doing, but may not be your ideal keiko partner. You also need some strong, encouraging sempai, who at a dan or two’s distance can set a good example and inspire you to reach your next kendo goal.