The vertical stack is probably the first thing that people will teach you when you start playing Ultimate Frisbee. It works on the basis that the defence are going to plan man-to-man coverage and force you to one side of the field. When they do this, the field is divided into the open side (the side they are allowing you to throw it to) and the closed side (the side that the defender putting on the mark is blocking).
In this situation, there are 5 players lined up in the stack, and one dump. The dump is for emergencies. If none of the stack can get open, then it is best to lose ground than to lose the disc.
There are two ways of losing your marker from the stack. Either take the red cut below and fake a long and then come short, or else take the blue cut faking short, before going long. If your cut, is covered by a defender, then it is important to sprint back to the stack to allow someone else to cut. Remember, the person with the disc has 10 seconds to get rid of the disc, so if your cut is covered, but has only taken 3 seconds of that time, then it gives somebody else a chance to cut before the person in possession has to turn around and look for the dump pass.
If a pass has been completed upfield, then the process starts again.
