This article explores the fundamentals of Horizontal Stack, a strategy used in Ultimate Frisbee. It explains how each position and role on the field is utilized within the formation, and how the concept of spacing is used to create cutting lanes and limit defenders. Additionally, the article explains how Horizontal Stack can be effectively used to move the disc up or down the field in a structured, systematic way. It also covers the importance of making proper outlet passes for successful and efficient transition play. Finally, the article looks at the importance of each player understanding when to cut and when to stay in their position to maintain the optimal flow of Horizontal Stack play.