Skyscraper
Adventurer
I'm not sure. Perhaps I'd grasp your idea better with an example or two?
Could you write a short example (doesn't have to be Shakespeare or anything - just legible!) which illustrates what you mean?
My first post (a bit long, I admit) doesn't do the trick, I assume?
Let me try to restate what I previously posted, first explaining my theory and then giving a concrete example.
For an AP I think that having the narrow-wide-narrow design (since it has a name, apparently!

The start and end of each of the ten adventures are the choke points. This is where you want to know where the PCs are to be able to bridge each pair of successive adventures. You may prepare, for example, key encounters at each adventure start and ending.
Between these choke points, the idea is to leave the area almost totally opened. What will the PCs do between choke points? Well, here is how I see how one adventure is structured:
1) storyline: the adventure provides a storyline that relates to the NPCs only (or just about, it might refer to the PCs at time = 0 for that adventure, since we only know where the PCs will be to start with). This storyline tells us what the NPCs will do, assuming that the PCs don't intervene. Some of these elements might be unavoidable (e.g. the king from a faraway land rides with his army to invade). Otherwise, the PCs may change the course of the events (e.g. if they kill NPC Alfred, then all events relating to Alfred are out of order and the DM improvises for anything missing. Normally, for predictable plot modifications, you can give options to the DM. The storyline is a day-by-day or week-by-week account of what's happening, and it's up to the DM to allow the PCs to cross that storyline by presenting them with role-play or battle opportunities, or clues.
2) Since battles will (or can) occur, the module includes a series of creature "encounter groups" that are not preassigned to a specific encounter or to a specific location. These are just pre-rolled baddies, set up in user-friendly groups usable by the DM whenever, during improvised play, a battle seems like the good thing to add at that point. Important and semi-important NPCs are provided with a bio, to link them to the setting.
3) Maps: you don't know where the PCs will go, so you need maps of the region and maps of buildings. Important places should be mapped out, and a number of generic maps (e.g. house, dungeon, castle, temple, street, forest, ...) should be provided for when the PCs will go someplace unexpected or generally elsewhere than in the few, main areas that are specifically mapped out.
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I'll give a concrete example of a campaign of mine that I played out for 2 years with my players in 3E.
Initial situation: the heroes start in a village that is attacked during the night and most inhabitants are killed or made prisoners - the latter fate for the PCs. They escape and want to avenge their village and learn what is going on (long story short). This is choke point #1, the start of the campaign.
Now the area is opened. I had some ideas of what they would do, but I wasn't sure. I had left clues leading towards three different areas that had minotaurs, orcs and lizard men, but they chose to go to a nearby town to warn the officials. I was not prepared for the town, but I had NPCs that were ready and I used them in the city as corrupted officials to confront the PCs. They fled the city and opted to infiltrate the orc hideout. I had that ready from the outset. They found stuff there and decided to go back to their old village to find more clues. I had not thought of this, but again used NPCs that were simply idly waiting for introduction in the campaign, and used them in the now destroyed village's ruins. And so on, until:
Choke point #2: they visit a large city where they find allies that will provide them with key information, directing the campaign towards somethign new.
Enter new open area, they attend a costumed party and meet a nuch of NPCs (I was ready for that one), they go to a nearby castle full of baddies (I was ready for that one too), they start a battle while spying in the basement of a noble's manor (not ready, but I used pre-prepared NPCs again), etc...
Until: choke point #3: they embark on a boat towards another kingdom, where the truth about the attack against their village lies.
And onto open adventuring again.
Etc...
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Only a small proportion of my encounters were pre-prepared. Most of the time, I just prepared NPCs in advance knowing that they might be useful and though about who hung around with who. Some were never used (minotaurs, lizard men) but I'd say 75% of what I prepared I eventually used. This is what I'd like to have prepared for me now.
Is that any clearer? I'm doing the best I can!

Sky