The 7th Commandment for Soccer Parents: Do Not Time Your Child's Minutes in a Game

Your child plays on the field for the amount of time a coach chooses to have them play. Your child is aware of how much time he is playing, you and he doesn't need a detailed review. There are many reasons why a child plays a certain amount of time. These may or may not be valid to you, but it's not your choice or your child's choice.

It’s not going to change the coaches mind if you have a detailed form on how many minutes and when your child plays in a game. It will not change a coaches mind.

If your child is dealing with a lack of minutes, he needs his parent to support him and not by
"going off" on the coach.  If it is a chronic issue, it may be time to schedule a meeting with the coach, Not after a game or when you are angry. Breathe, get calm, and then text the coach at least a day after a game, and ask for a meeting with him, you and your child. 

If you act like an obsessed parent that's not a good thing for you or more importantly for your child.