My 12U DD went to a substitute PC last night who was a D1 pitcher. The PC said she looked great but needed to work on keeping her hips open and not close them so fast (hips should follow hands). I have told her this repeatedly, have bought her the perfect circle training aide and she also does...
Many coaches have their hitters do some version of one hand drills with a short bat either off a tee or soft toss. Some do top hand only, some do bottom hand only, and some do both.
To aid in these drills and possibly help prevent injury during these drills the hitters must have a proper grip...