I’m not going to bother to address your grandson’s baseball potential anymore. Until he proves otherwise on a big stage it’s little or none. His chances of playing college baseball are slim and none. Your ignorance regarding baseball, is mind boggling. Stu Miller pitched fifty plus years ago. Do you think there just may have been some advancement in average velocity over fifty years? You have absolutely zero clue what it takes to become a college baseball player. Maybe you’re just trolling to see who will continue to bite. If so, shame on me. I’m beginning to wonder if you’re a teenage internet troll.
You provided one of the best tips he’s not a college pitching prospect. You’re still catching him. When my son got to sixteen I started becoming afraid to catch him. I played college baseball and I started wondering if I could pick up, block or get out of the way of every pitch because of the velocity and movement. And his velocity was still developing.