The meaning behind BWAPI region priority

It occurred to me after viewing this image how the Broodwar built-in region priority system works.

In this visualization, the yellow colored regions have a priority of 2, and the blue ones are priority 3. There are no dividing lines between the yellow regions, just note that the larger ones are actually made up of multiples.

Priority works just like the number in Minesweeper: it is the number of distinct impassable terrain areas that a region touches. That is why there are random yellow regions everywhere in this map, as there many little doodads scattered around that will make a region in the middle of a clear area have priority of 2. The built-in analysis system thinks that it is a choke.

Unfortunately this discovery means that the BWAPI regions are not very valuable for choke detection. They are still a good alternative to implementing a map-grid system, as they are approximately grid-like, but conform to impassable regions so you won't have a grid square which is split by a cliff.

La Mancha

Now I finally see why the map is named La Mancha.

That is clearly a windmill in the center of the map!