Four man cup

From Ultipedia

The four man cup (aka '1-3-2-1 zone' or 'wall') is a zone defense. This cup has one defender marking the player with the disc while the other three form a wall. There are two mids and a deep. The individual on the mark (called the rabbit) follows the disc and is solely responsible for checking any player with the disc.

'1-3-2-1' refers to the number of players and their relative positions - in this case, there is one defender acting as the rabbit, 3 defenders forming the wall, two mids and a deep.

A key to the effectiveness of this zone is to not allow any throws through the middle of the wall. Also, [trap|trapping]] the frisbee tends to produce a more effective four man cup rather than a middle force.