Maybe because > He shares a lot of his secrets ? Teachers don't have to be the best at the _thing_, they should be really good at explaining concepts. Maybe

Maybe because > He shares a lot of his secrets ? Teachers don't have to be the best at the _thing_, they should be really good at explaining concepts. Maybe T90 is the people watch when then want to go from zero to average? I don't want to be coached by the best tennis player in the world, it would be a waste and I couldn't do any of the things they could teach me. A solid above average player that knows my limits and can explain how to correct flaws would be much better (for me).