|First, let me say the most fun I have had playing ultimate was in the zone we played at Princeton. The first zone (I believe) was used by Rutgers in their championship season of 1975-6. That winter Princeton developed one too, and started using it very successfully that spring. The original plan was to switch between zone and man, but zone worked so well and was so easy we very rarely switched back to man.
The first incarnation, as designed by the team leaders, seemed to go up the evolutionary scale as you moved towards the back: the fronts were beetle-browed, brainless runners who would blindly follow the disc, the middles relied on technique and positioning over physical prowess, but the backs were the cream of creation, wise and canny in the way of the disc, reading the whole field and directing the rest of the defense. As we up front learned more about the game and our positions, we began to show how smart fronts could make the zone even better, shutting down the give-and-go or swing passes, helping the middles, and disrupting the offense. This was the first big contribution by my generation to the team.
The zone we played was very different than the cup-based zones that are prevalent now. The middles sagged back as far as possible, and the offense was encouraged to push short passes up in front of them. The idea was to contain and recover - if the offense could complete 50 passes against us they would score, but few teams had the patience or skills to do that.
The strength of this zone was in its middles. Playing so loose, it was very difficult to get the disc through them or around them, because they had time to get to the sideline before the disc could swing around them.
Very reluctantly, I do not advocate trying this zone now. The skill level has gotten too high. In the 70s, most teams had only 1 or 2 people tops who could throw the length of a 60 yard (not meter) field, and a hammer was a rare beast, considered almost uncatchable by almost everyone. Using a hammer to drop a pass behind the middles would be too easy to most of today's players, and this flaw alone ruins an otherwise beautiful defense.
This type of zone was common into the early 80s, and so well accepted I recall when I tried getting a summer league club team to switch to man, being told "man-on-man cannot work unless every man on your team is faster than every man on theirs".
While I am not sure of the genesis, I assume the cup zone grew out of attempts to overcome this flaw. Rather than containing the disc, the purpose of a cup zone is to deny the first pass by surrounding the thrower with a ring of defenders just at (or maybe just within) the legal distance.
This is its main flaw. Like against a force, I think a good thrower should be able to pick it to pieces. Unlike the older loose zone, a cup zone is in real trouble on a completion. The entire cup must follow the disc, and until they are back in position the defense is vulnerable.
Its strength is when it is set. Breaking the zone requires good cuts and throws. A successful team will be able to keep the momentum going once started, never allowing the zone to reset. When it is scrambling the zone is pathetic; once it is set, it is only beatable.
There are 3 ways to beat a zone. In order of desirability, you can go over it, through it, or around it. Coincidentally, these are also ordered from hardest to easiest. A long pass is of course the best option, but not that easy to accomplish. A pass through the cup (middles) is confusing for them, and leaves the remaining deeps overwhelmed for a few moments at least. A swing pass, the easiest pass to make, is also the simplest to defend, since the entire cup knows it must sprint to follow the disc.
Defense is a balancing act between pinching off the middle and smothering the wings. If the defense spreads too far the middle is vulnerable, if they close in too much it takes too long to recover against a swing. It is up to the offense to find which side the pendulum is on and take advantage of it.
One thing to look at, always, is to do the unexpected. If the offense begins a swing, the cup will stampede after the disc, expecting the continuation. This can leave them vulnerable to a pass through the middles back towards the side the swing came from. This pass, if it can be made, is a guaranteed zone breaker.
Here are a few other thoughts about breaking a zone:
There is a different psychology in breaking a zone. In man-on-man coverage when you make a cut you generally want the disc. The first cut into a cup often should be a "martyr": his purpose is not to get the disc but to force the cup/middles to adjust, moving them out of their set positions and giving a better opportunity to a closely following cutter. Attacking a zone one by one lets them adjust to the threat, and then recover to face the next one.
There is also a big similarity between breaking a cup (or any other zone) and the Empty V. I think many people attack the zone like they do a man - look for an open player and try to get him the disc. By paying only secondary attention to the zone you fall into its trap.
A better way is to look first for the gaps in the cup: where can you throw if you have the opportunity? Once you find one, wait for a cutter to move in. To complete a (short) pass you need to find an open cut aligned with a gap in the zone. Cutters move fast, the gaps move slowly. It makes more sense to pick a gap and wait than to find an open cut and hope you can get it to him.