This article discusses the concept of the "vertical stack" in ultimate frisbee. This strategy involves players lining up in a vertical line instead of the traditional horizontal line, creating a wall blocking the opposing team from getting the frisbee. This creates more options for the team with the frisbee, as well as opens up striking lanes for throwers. The article also discusses ways to break the vertical stack such as throwing high passes, cutting under players and switching fields. Overall, the article explains the various benefits and tactics associated with the vertical stack in ultimate frisbee.