In this scenario, Blue is on offense and has set up in a standard 5-vs-5 vert stack; Red is on defense and is forcing backhand.<br> <br> The key is for the last two players in the stack (Blue 4 & 5) to get out of the way and create space deep for the player setting the stack (Blue 3).
Blue 4 & Blue 5 coordinate which side each will cut to (it doesn't matter who goes where, just that each goes to a different side to draw their defender and prevent picks).<br> <br> When the disc is checked in, they begin their in-cuts to either side, creating a huge, undefended space for Blue 3 to strike out into.
Blue 5 & Blue 5 make their in-cuts...
...and Blue 3 is left with lots of space deep, looking for whatever throw is easiest for the handler.
So, that's the zipper. It's pretty effective if we mix it into our play calling every once in awhile to keep the defense off-balance one way or another.