This trick works best with a man on first. Have the batter hit a ground ball into the outfield. Let the player on first go all the way home. If it was a good hit, he will be safe. Around the time when the batter has reached halfway to, or is already on, second base, the outfielder will throw to home plate. When the batter touches second, stop his running. When the outfielder's throw gets to the shortstop (who will if done correctly, throw to home plate) , wait until he tosses it home. As soon as the ball leaves his hand toward home, get the man on second to go to third base. If done correctly, you will now have an extra run and a man on third.