The dad probably was picked last in PE.
This is difficult for everyone to watch. The head coach needs to take this father aside and let him know this is unacceptable and that he is getting in the way of the coaches doing their job. From my experience, this usually doesn't mean that it stops. It is more likely that the father will take his kid off the team.
From what I see of the young lady, I would bet the dad will continue to drain the fun from the game for his DD and she will find a way to quit: either by sinking in performance or refusing to play at some point.
He's not a bad guy and he really does love his daughters, but clearly he's pretty driven. He also has a DD that is 15 that is doing very well.
I don't know him well enough to say what needs to be said to him. Since we are relatively new to the team, I don't have any confidence he could receive that kind of message from me. He has known the coach for a longer time. I'll see what kind of traction I can get from there.
He thinks it is in her best interst to be a better player and he doesn't understand why she hasn't made the leap to that level yet. I am certain he doesn't understand that his behavior, especially getting mad at strikeouts, is preventing his DD from making substantitive improvements. She would have to fight through the draining emotions of her dad's disgust and disappointment, to get to a mental place where she could make some understand what to do and make meaningful changes in her swing. Apart from dropping her hands, there a lot to like in her swing and athleticism in general.
Unfortunately, I see a lot of myself in this guy and it's not pretty. I have heard several folks say they are recovering crazy daddies. I can relate. I am taking a much more positive approach with my DD. Before I was much too direct and unrelenting in my approach. I wasn't making it fun. For some time I have had a haunting thought that what if I create a great softball player and lose a daughter. That's frightening. I don't always hold the positive line even now, but I am constantly on the lookout for how my DD is receiving my message and I am trying to adjust my "help" accordingly.
The dad probably was picked last in PE.
The HC can easily implement a policy my DD has played under during 12U and really enjoys to this day. "Once you drop your DD off, they are mine. There will be no coaching from the bleachers, no visits to the dugout. You have entrusted my to coach your dd and I will coach them to the best of my ability. No bringing snacks, there is no food in the dugout. No bringing water, I will provide water and Gatorade for her to drink. If you prefer to coach from the bleachers, you may take your dd elsewhere."
It also made it a lot nicer on the parents to be able to just enjoy the game and cheer.