Maps reveal the structures of ‘Choose Your Own Adventure’ books
Shame they didn't map some of the Fighting Fantasy books ( http://www.fightingfantasy.com/ ) or Steve Jackson's Sorcery Series ( https://en.wikipedia.org/wiki/Sorcery! - now made into a series of mobile apps http://www.inklestudios.com/sorcery/ ). Jackson & Livingstone really pushed this format far more than the "Choose Your Own Adventure" books.Most of all I remember "Creature of Havoc" ( https://en.wikipedia.org/wiki/Creature_of_Havoc ) as being amazing and extremely hard. Instead of being an adventurer you play a monster with limited IQ forced to unravel the mystery of your own existence. It employed various techniques that prevented cheating like "If you have the key, add the number written on the key to this page number to open the door". One of those puzzles still has people discussing it http://laurencetennant.com/bonds/creatureofhavoc.html ( contains spoilers ). At 13 years old it took me and a friend 2-3 months to finally crack it.