Do you think the engine compares a players Driving and Passing skills, and decides whether the player should shoot or pass the ball? So players with higher passing will provide more assists and those with higher driving will take more shots. Or maybe just the higher the driving skill, the more chance there is for a shot to go in.
i am quite sure that is does it, because the player look for the best shot. So whenu see an easy opurtunity while drive to the hoop they will take it, rather then a difficult pass(or a pass which brings you in a weaker situation).