One of the critical aspects of the craft of writing that I've rarely seen formally taught, possibly because it is extremely subjective and dependent on genre, category, and tone, is PACING. I have some thoughts on the subject.
What IS pacing? IMO, it's the speed, rhythm, and level of tension in the narrative --FROM THE PERSPECTIVE OF THE READER. Which makes it super hard to put a finger on b/c readers' perceptions on this are ALL OVER THE MAP.
I've had "So boring, DNF" and "Gripping; literally could not put this book down" as reviews for the same book. For EVERY SINGLE BOOK I've written. Most authors are in the same boat. What's too slow for one reader is unputdownable for another.
Pacing in a literary fiction novel is WAY different than in a thriller which is WAY different from a YA fantasy. It drives me insane that some people think Arrival or Ex Machina are too slow (WUT they're PERFECT) but there are entire genres where I have to fight to stay engaged.
So when a reader says "too slow" often they mean "I wasn't invested" or "it wasn't for me." They rarely say it was "too fast" but they will say it was shallow, trite, or uninteresting to them. So how the heck do we are authors figure out what the "right" pacing is for our work?
First, you must have a sense of your ideal reader and an understanding of the conventions of the category and genre you're writing in. That means reading a lot of best-of-class work in your field. And having a clear vision of what makes your work appealing to your target readers.
e.g. Sure, Tom Clancy's long explanations of military tech slow the narrative down. But they're EXACTLY what his target reader wants out of his work. My adult fantasy epic novels take the time with details of magic & worldbuildling b/c I (and my ideal reader) want it.
OTOH, my YA editor pushes me to convey the SFF worldbuilding w/ FAR more economy b/c of the average YA reader expects less of that detail. So yeah, know your field and read enough that you have an intuitive sense of the expected pacing.
Second: I think of pacing less in terms of total speed and more in terms of tension and release, rhythm and flow. At any given point, ARE THINGS HAPPENING THAT ARE CRUCIAL TO THE NARRATIVE? Is tension building? When it's released in one area, is it cranked up in another?
I make sure there aren't two big fight scenes in back-to-back chapters. (Those fight scenes are precious, they must be placed well.) Or two big emotional convos in a row. Or too much of one POV before moving to another crucial POV. I color code the shit out of my Scrivener file.
Think about it this way: a monotonous dance track may be fast...but it's still boring. An *interesting* song has variation. Same w/ stories. Speed up, slow down, reverse, take unexpected turns, keep the reader anticipating CHANGE...even in the small, quiet character moments.
Finally: Pacing is one of those areas that I think, more than any other part of the craft of writing, relies a lot on FEEL. Does it FEEL right to you as the author? Is it fulfilling your vision? That comes primarily from gut instinct honed from experience.
I've seen writers force an action scene into the first chapter to "hook" the reader/agent/editor when it's not what the book calls for. Be confident in your storytelling choices. Story pacing is like sex: Variety is nice & Go at the speed that feels good to the parties involved.
