If you follow Planet IF, you're already all over these links. But if not, you gotta start following two blog-post series that have been rendering early IF and choice-game history into a fine itchy mist of detail and insight.
On the CYOA side, Sam Ashwell has been analyzing various corners of the genre in terms of structure -- with lots of chewy graphs and statistics.
- CYOA structures: The Cave of Time
- CYOA structures: Tween Romance
- CYOA structures: More Packard
- CYOA structures: CYO-RPG
- CYOA structures: Spin-offs
- CYOA structures: IF
And on the game history side, Jimmy Maher has been playing through every game that can be plausibly be called an IF ancestor. He's trying to find the versions closest to the original source, and he chocks each game up on a solid base of history and context.
- On the Trail of the Oregon Trail, Part 1, 2, 3, 4, 5
- In Defense of BASIC
- Hunt the Wumpus, Part 1, 2
- Will Crowther’s Adventure, Part 1, 2
- The Completed Adventure, Part 1, 2, 3
- The Trash-80, Part 1, 2, 3
- Eliza, Part 1, 2, 3
- (Scott Adams's) Adventureland, Part 1, 2
- And then another two months' worth of posts...
...You know what, I don't need to paste any more links here. It's not about this page, it's about Jimmy's. Go look at the DA post list and start scrolling back.
Both series are ongoing, so stick them in your feed reader or your instant paper or your stone burner or whatever technology fries your eyes.