Narrative beat is something you'll find a lot of novelists and other professional writers banging on about. It essentially means rythm within a story structure and acts a bit like a hypnotist's pendulum, mesmerising the reader and making the business of reading the book more comfortable, natural and entertaining.
Think of a piece of music you like. Unless you're a fan of freeform jazz, chances are there's a drum beat, or a rythm, or at least a set pattern to the music. Without this, it's just a bunch of noise and very hard to listen to.
In the same way, Gamebooks should have a narrative beat. You can produce this when writing by breaking your story structure down into a set number of 'episodes'. The natural place for such episodes is bottleneck points. These are spots where every reader will eventually reach no matter which paths they take. I'll talk more about these in another blog post, but for now you should be aware that such locations exist in pretty much every single gamebook ever written. Without bottlenecks a coherent story is almost impossible.
Begin, of course, with paragraph 1. The last beat in your narrative rythm will be 400 (or the last paragraph equivalent). Using a flow chart, work out approximately how many entries the reader will go to before they hit the first bottleneck. Regardless of which direction the reader takes, this should be more or less the same amount every time. This eradicates short adventures caused by taking the direct route and failing to investigate side-rooms, branching paths or mysterious doors (that kind of thing).
At each bottleneck, insert some kind of narrative structure. This might be a small amount of exposition, a meeting with a recurring character, a chance to rest and recuperate, or some other kind of positive encounter.
Enemy encounters and combat should occur halfway between bottle-necks, with other types of encounter occurring approximately halfway between each bottle-neck and its respective combat encounter.
You might envisage this:
START -- Encounter -- COMBAT -- Encounter -- Bottleneck -- Encounter -- COMBAT -- Encounter -- END
You'll likely want more than one bottleneck in order to push the narrative forward, since important parts of the story will need to be experienced by the reader of they are to make sense of the reason behind their adventure.
Give it a go and see how it affects the flow of your own gamebook creation.