Writers don’t just stand on the shoulders of giants. They exist in a community that doesn’t have to be a giant yet to know what they have learned themselves. I have never heard a better definition of where the story begins than my friend, Leslie Carmichael.
Stories can start with the author shooting the moon. Great or very lucky writers can create a perfect moment to seamlessly braid enough worldbuilding into the actions of the now so that the reader is given exactly as much information as they need to contextualize the story’s stakes. They are near-instantly engaged with the unfolding events.
Most other writers just need to start with something that shakes the character out of their everyday life and into the part of their life the story exists to capture. Starting at the beginning of what started that landslide means having two and a half more chapters to do what the first beginning must do in a few paragraphs.
But there’s an added factor of difficulty with stories that start in the middle of the third chapter. It is always easier to start small and build than it is to start large and build larger. If the action created in a stunningly effective in media res opening is followed with chapters filled with world-building, the initial momentum slows the first chance it can.
Stories that open with big, emotional stakes must build bigger, more emotional stakes from that point. But stories that start with a moment of change can provide the most opportunity for character growth to the story. Starting after the character has already made difficult choices robs the reader of experiencing the cost of making them firsthand.
But more importantly, it robs the reader of witnessing the first decision the character ever makes in which any outcome still has a cost. They never see who the character was before they already decided their path. The character growth possible in a story that starts in the middle of the action is already less than what it could have been had their whole story unfurled.
Once the story starts, telling the reader who the character once was is only exposition told through backstory.