Every zone has a weakness, there is too much of the field to cover with just 7 people. If you play the same zone often enough, almost any team will be able to discover and exploit the zone’s weakness. There are two ways to combat this, both rely on deceiving the offense. First, if you allow your players to gamble, you can have them gamble in different ways. This will effectively change the weakness of the zone, and possibly change an expected weakness into a strength. If you gamble the same way every time though, the offense will recognize the new weakness and exploit it. If you can anticipate when the offense is going to start trying to exploit a weakness and change your strategy to take that weakness away first, all the better.
Here is an example of changing a gambling strategy to keep the offense guessing: You’re playing a 2-3-1-1 zone with 2 markers, 2 wings, a middle, a short deep, and a deep deep. The markers are trying to take away the deep shot, and the 2 wings and the middle are just trying to contain the disc. One weakness of this zone is a handler homey. The offense can just do give-n-goes in front of the middle and wings and slowly move the disc down the field. If the middle or short deep recognizes this, they can crash and try and make a bid on one of these passes. If the handlers are intent on working the disc this way, they will likely not be looking over the top to the new weakness where the short deep used to be. Next time, even if the short deep is in his or her normal position, the offense will be more tentative in their homey. Now, the short deep can slow down the homey by getting closer to the disc, but should be ready to gamble on the over-the-top shot.
The second way to cover up a zone’s weakness is to play more than one zone, preferably with different weaknesses. The more zones you can effectively play, the longer it is going to take for your opponent to decipher the weakness in your zones and exploit them. Every new zone you throw at them will require some time to decipher. This gives you more opportunities to get D’s. Even if they are able to figure out all your zones before the end of your game, you’re still putting stress on the offense because every time you come down the field, they have to first decide if you’re playing man or zone, then figure out which zone you’re playing. Then they have to remember correctly how to attack the defense. When you add gambling positions to the mix, it can be even more frustrating for the offense.
Once you’ve got several zones that your team can play effectively, you can use one zone to set up another. The easiest way to explain this is to give an example. Say you’ve got a standard 3-2-2 trapping zone and a 4 person cup, where the 4th person takes away the dump. You can use the 3-2-2 trapping zone to set up the 4 person cup. The offense will recognize the trapping zone and attempt to dump swing around to the weak side of the field. Next time down, throw the 4 person cup at them, and have the 4th person bait the dump, then go for the swing pass. This can often get you a D, and if you’ve had a good pull can sometimes get you a Callahan.
I'm working on a few extra items to maybe throw into a part 3 including defending the 2-4-1 and some 'advanced' zone play. I'm also curious what people think about how offenses would respond to the above ideas. Do they really think about what the zone is doing or do they just do what they know works for them against 'zone'?