All stories inhabit a ‘world’ of one kind or another even though we don’t usually talk about ‘world building’ outside of genres like fantasy. Distinctive ‘worlds’ can add a great deal of interest to a story and I am struck particularly strongly by this when I pick up a Dick Francis novel. They might be getting a bit dated now, but they’re a fantastic study in using a ‘narrow’ world to support very interesting stories.
Dick Francis was a jockey and involved in racing much of his life, so following the idea of ‘write what you know’ he set all his crime novels in that same world. And it is a world. Trainers, and owners and strappers and jockeys provide a diversity of characters and motives for wrong-doing. Stables, race tracks and weighing rooms provide well defined settings. And because of the ‘narrowness’ of this world, an amateur sleuth is a believable hero because being a jockey (usually the protagonist is a jockey) they are experts in navigating the environment.
Even if you’re not big on crime or horses, it’s worth reading one of these slender novels (pick an early one) to see this type of ‘world’ in action.