What a fantastic article. I wonder how more rules-oriented gamebook series [1] would fare in this type of analysis. They do tend to lead to an "ideal" ending, as the author noted, so perhaps they wouldn't be as interesting. The progression graphs would be interesting to see, though.<p>[1] Such as Joe Dever's wonderful <i>Lone Wolf</i> series. The republished versions available at projectaon.org --- and apparently back in print now --- are just as much fun as I remember.