It depends on the teacher. Some are great and some...are not. Also, the martial arts world has a number of people that go around trying to hold unregulated fights with others, just to say they're better. It really doesn't stop bullies. Stephan Segal is a great example of this. He would regularly hit the stuntmen he worked with just because he could. He also boasted of winning a fight to the death of anyone that would fight him. Several people tried to take him up on the challenge but he never answered it.