The drop pass is a pass that is used in the offensive zone quite often. It is a pass that I see happening quite often in games, and is one of the easiest passes to fake.
In order to successfully complete a drop pass the person carrying the ring must be closest to the goalie while the person who is receiving the drop pass is on the outside. This way the ring is protected until the person receiving the pass gets the ring.
This pass is very useful because the person carrying the ring can draw the centre with them so the person receiving the pass can break into the triangle and get a shot on net.