From @kottke: 

The newest editions of Choose Your Own Adventure books come with maps of the story structure that depicts all the branches, endings, and links of each story.

As someone who diagrammed these books for fun, I am ON BOARD with this

In middle school I had a hypothesis that there were a only a few map templates that the CYOA writers had, and the storylines were just fill-in-the-blank exercises to fit the templates.  A bit cynical, but I thought they could cut down the cost and writing time required, and it’s not like the plotlines themselves were works of art.  Maybe the map templates wouldn’t be followed exactly, but you could make them fundamentally isomorphic and still avoid having to do the math of rolling your own CYOA structure.

Anyway, in college I bought a bunch and diagrammed out the paths. After mapping out fifteen books …. THEY WERE ALL DIFFERENT. I still can’t really believe it.