This is one of my favorite drills to teach the lower half to be used correctly. Can you put the tea on the outside corner of the plate and the Bosu ball is straddled by the hitter. The object of the hitter is to take an aggressive stride and then take a swing where he gets the ball into the air towards the opposite field. Trying to keep the ball true and straight. As the hitter swings, his back knee needs to finish on top of the Bosu ball. This ensures that the back hip rotates completely through the ball. This drill is excellent and giving the hitter a feel of how to use the ground and his engine correctly. At times it is a "aha moment" for a hitter.