This defense sets up in a traditional 3-3-1 formation. The "babysitter" is marking, red2 is the middle of the cup and red 3 is the off-point. The next layer includes a short deep and two wings. Finally a deep deep guards against hucks. Standard stuff.
As the disc swings to the force side the zone changes. Instead of the Babysitter chasing to set up a mark, he matches up on the central handler - he's babysitting the middle handler (who is often the strongest thrower on the other team) . This ensures that an easy reset to the middle handler is much harder. The middle of the cup (red 2) sets the mark while the off point (Red 3) takes away the inside break. The wing 1needs to quickly assess the most dangerous threat on their side - either the opposing wing (7) or a popper. Wing2 on the far side moves toward the middle to help support the short deep, and threaten throws to blue 1.
If the mark (red 2) and the off point hold the most likely response (particularly from weaker teams) will be to try and crowd the disc. Blue 2 (the middle handler) is likely one of the stronger players and will probably move to support his trapped teammate. This is great. He's being marked man-to-man by our Babysitter ( a very strong defender). Note that the offside popper (4) has moved toward the middle andwing2 must decide whether to follow or let the short deep take him. At this point the offense has a very limited set of viable options. There's the blade or hammer all the way across the field to either blue6 or blue1 or forcing something very risky near the sideline.
Let's assume that they manage to reset it to blue 2.
The babysitter sets the mark and we fall into a more traditional cup with red 2 as the middle and red3 as the off point. However, you'll note that we've pushed them to use only one third of the field. Windows are getting tighter. If the reset is fairly close to the sideline (as shown in this step) then wing2 has to decide which of three players is the greatest threat blue 1, blue 4 or blue 6. Communication with and from the deep deep is key. As set up the wing should move with blue 4 leaving blue 6 for the deep deep. Moving to cover blue 1 (handler) is too risky.
If the disc moves through the cup players two and three set up their mini-cup - with one person marking and another playing the "middle of the cup." The Babysitter stays with player 2, ensuring no free reset to their strongest player. NOTE:If the disc goes through the cup there's a quick moment of danger. A really strong team could immediately reset to blue 3. But we're betting that all the traffic and confusion will make this harder, or that if it happens blue 3 will have no viable options.