Pacing is important. If events in your story happen too quickly, or the story is over almost before you start. If they happen too slowly, your reader will get bored and abandon the story. You need action, exposition and back story in every work. These items need to be in balance. This is pacing. Intersperse your action with back story and exposition.
A common advice to writers is to start your story with action. Generally, this is sound advice. I once read a book where a woman found her dog had gotten out and went in pursuit of him. She raced out in her pajamas, met a stranger — she was new in town — and went for coffee with him at a coffee shop. This is a situation where the author started well, but added exposition in the wrong place. The story lost plausibility. Most people out looking for their dogs in their pajamas do not stop for coffee in a coffee house with someone they just met. At least, I don’t know anyone like that. If you are going to do that, at least have your character get dressed before discovering the dog got out. That would be better.
Another book I read had back story in the wrong place. Three amateur sleuths were given ten thousand dollars to investigate a murder. Now in this author’s defense, the three were eating. One of them stops thinking about the murder to indicate that he had health problems and needed to watch his diet. I’m not sure a real person would do that in similar circumstances.
These are minor problems that popped me out of the story. This is what you need to avoid. You want your reader to be immersed in your story from the first word to the last. Pacing lets you do it. Slower areas are important to allow your readers to relax a bit between bursts of action. I’m sure that’s what the second author above intended, but she failed because she ended the action too soon. Most people I know wouldn’t stop looking for their dog until the dog was found. Then, they
would go for coffee. This is another point where the story lost plausibility.
So how to avoid these pitfalls? One method that works well is outlining. Check your outline for the action scenes and make sure that you have a balance of exposition and back story in there as well. If you prefer to write the story with no outline, take your rough draft and separate it out by scene. For this method, you might want to color or highlight the text, green for action, orange for exposition and blue for back story. Whatever colors you choose. What color shows up the most? That’s where you need to use the balance.
I’m not saying these methods will work one hundred percent of the time. They are just tools to use. There are others to be found on the internet. If you Google the keywords pacing and writing, you will find a ton of sites to help you identify and fix your pacing issues. Good luck and good writing.