1. If you are not the coach of the team then you should keep quiet from the sidelines as it is the coach's job to coach your son. There's nothing more annoying to a coach than a parent coaching from the sideline.
2. If you are the coach then why are you "screaming at him to push off and rip it?" Rather than drawing all the attention and focus on him in front of all the spectators call a time out and walk to the mound and have a private conversation and help him process his feelings of hitting a batter.
In terms of youth baseball pitching mechanics...
3. Yes, you can definitely overdo it and in my opinion you already are. The first priority for 8 year old is creating an environment for fun. Help him fall in love with the game by encouraging him and the rest will fall into place. be quick to listen and slow to speak.
4. Keep the mechanics fairly basic at his age at game time. No exaggerated movements. Focus on glove side control (as Roger stresses), decent stride and lead foot landing pointing towards home. Get these going and you'll have him pitching in the strike zone.
5. You should not focus on one thing, such as pushing off or throwing hard, without keeping it in the context of the "big picture". Repeatable mechanics and practice of them will result in the control he needs. It's just not overnight.
In terms of the mental part of pitching, which is probably the most important at this age...
6. Don't put him in a position he can't handle. Kids at that age have good days and bad. When he's off, don't push it and don't put him in a pivotal role (starting or closing) if possible. Most kids at this age don't have the self-confidence to work through a bad outing. When this is occurring, make light of the situation and get them out of there.
7. Don't emphasize pitching speed. I keep telling the kids that once the mechanics are perfected the speed will come. Not to worry about it at this age.
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