DD and I went to a college camp ( perennial top 20 school D1) a short while ago and hitting instruction was pretty basic. Load, stride, get your rear elbow into the slot , stay inside and extend through contact. They demonstrated one arm drills front arm keeping bathead up, back arm punching through. Not bad advice I guess but not top tier instruction. We also did a private hitting lesson in the spring with one of the asst coaches. He spoke about kinetics and staying inside the ball. Haven't been back to him because of the intense summer schedule. They also spoke of push through contact at the camp.