Back Checker Strategy, the third book in the Backgammon Odyssey Series, categorizes back checker formation into five stages: Initial, Advanced, Completed, Solo, and Butterfly stage. The stage you are in affects whether you play boldly or safely on your side of the board. You also learn how to handle your back checkers in each stage. A butterfly stage is a situation in which you hold a 3-point anchor, but why? You’ll see the exact reason in chapter five. You finally learn new concepts, “F13” and “Glued back checkers,” etc.