Rog,
Sometimes us hitting folks...myself included make things too difficult but as many have said sometimes it is too hard to figure out what is going on without seeing some video. If he is a RH hitter and he is hitting ground balls that are not hit to hard to the SS, he may just be letting the ball travel too far...letting it get to deep and the result is he would be hitting the ball from the trademark in towards his hands.....resulting in a lot of ground balls to the SS.....that is providing the balls are on the inner part of the plate........if the balls are on the outer part of the plate and he is a RH batter he may be making contact too soon and not letting the ball get in further, which will result in a GB to SS although the pitch outside will be hit a little harder than the one on the inside of the plate.
I hope I have not mudied up the waters....O42