CorrectionI just realized that dividing the positional zone into two areas, with one area have 2X situations and the other 1X, is not the most effective.
The effective way is to decide, up front, what the total number of areas will eventually be for a single positional. So let's position X has 10 possible positional areas (which is responsibility at a very detailed level, eventually). So when you divide into two positional areas, the new area would be only 10% of the total possible situations. You're biting off a very little chunk of space and defining a few very specific situations where the player should be in that little space.
That's much easier to learn, and it's easier to design drills around as well. It's like Simon Says--the coach puts the puck or players into a particular situation, and they decide whether to jump into the small, new area.
So you have a big space initially, and players skate around in that space all the time. Then you take little chunks of that space and become more specific, building gradually into a more complex understanding of the entire space.