The Bullseye Cup acts as a 30% cup reducer designed to make you set your putts out on a more accurate line to the hole depending on the break. It brings to mind Ben Crenshaw who would ask the question where you want this putt to drop. Left lip, straight in etc? And with some ease could play the shot down to a tee. If you would like to become an accurate putter the Bullseye is a great place to start.