Sideline trap

From Ultipedia

A Sideline Trap is a short term (typically one throw) tactic used by a defensive player (or cup if the defense is playing zone) where the desired result is to severely restrict an offensive player's throwing options to passes up or down the sideline. In order to achieve this, the defender applies a hard sideline force (disregarding any other defensive strategy or force) for the one throw from the sideline. If a cup is applying a sideline trap, the marker applies a hard sideline force, while the other members of the cup stand close to the sideline on either side of the thrower to make the line passes even more difficult. Often the cup defender covering the dump pass in a sideline trap will concentrate their defensive efforts on any offensive players hanging back, rather than just blocking the line pass.

Sideline traps can be very effective, but a skilled thrower can often defeat the trap with a well placed hammer.