I remember part of the difficulty was the angle and speed of the ball. Sounds like your son has the ability to hit faster straighter pitches off you. Well those are coming from 45' away at 6-6.6' high and I would guess in mostly a straight line. 9YO pitching - as mentioned - is wildly inconsistent - probably closer to modified pitch softball where the ball starts at 4' and has an arc to the path. At that age, I used to sit behind the L screen on a bucket and just lob the balls at the plate. The one problem with that is then when you get a good pitcher that can throw "heat" (or what is heat for 9YO)...the timing will be off. Just enjoy the time you have with him... regardless of the outcome. At some point hanging with dad isn't gonna be cool.