In the early-90's I saw Vonnegut give a presentation in which he talked about his story graph idea.

However, the video linked to in the article appears to end before the most interesting part.

https://www.youtube.com/watch?v=9-84vuR1f90

Hamlet. It's never clear whether what's happening belongs more toward the good or bad side of the vertical axis.

The curve you get is a flat horizontal line. That's art. Never clearly good or bad but profound ambiguity.

Also, for those interested in the systematic (graphical) formulation of stories, check out StoryGrid:

https://www.goodreads.com/book/show/25455700-the-story-grid