have a charcter with the body check ability be on the bases. then when the player is going to the next base (MUST be on a tag out play NOT a force play) have the play WALK then when the ball is about to get to the basemen make sure your player is very close to the base then you make him RUN with the B button. The ball and the runner should reach the base at the same. The easiest way to do this is to make the player steal After the pitcher thorws the ball, then let the runner walk until the catcher's throw is half way there then start pressing the B button like crazy. Practice this a bit (about 7 times) and it will be perfect.