Im a 45y old player and I play for fun every thrusday with 3 other guys and we have a coach. I have pritty desent technique myselfe and Im allways willing to learn more but our coach ignores all questions regarding personal technique. We got into an argument last thursday and I was beeing flamed for giving one of the other guys (on a previous session without the coach) some pointers on how to get a better 1st serve. One of the things I advised him was to hit the ball flat. To take an estern forhand grip and to hit the ball more direct and flat insted of allways just hitting the ball with a slice. The coach got really upset to what I had been advising and told the other guy never to aske me for any pointers on how to play tennis. He said nobody uses such a gripp and it was some of the worst advice he had ever heared. I used to have a very week first serve untill last year when an instructor told me to change my grip from hammer to eastern. Wow, nobody in my coaching group can brake my serve anymore. So, whats up with the coach and was my advice really that bad? Should I change back to hammer myselfe?