Gufbal1982
Purple Belt
I'll agree as well. There should be a minimum and an instructor should know his/her students capability going into a test.
I will say that I have always been an advocate of "a black belt is a black belt no matter what age that person is." if a student can't hang with the other black belts, than that person is not ready. I know for a fact that I shouldn't have gotten my ranks so young. I know I was only originally promoted because I wanted to run a school and the only way it was happening was to rush me to a rank I wasn't ready for. If I were to take that test now though, I'd be ready and willing to do what I need to do.