It's always written out as something like this:
da DUM / da DUM / da DUM / da DUM / da DUM
If you say that out loud, stressing the second beat, it has this certain flow to it. Bottom line is that every manner of speech has a sort of cadence and rhythm underlining the writing. Pentameter is very complete and perfect, which is why it sounds so full when you write a sentence in the meter. For Example:
"as ONE sees LIGHT the BLIND man WEEPS in PAIN"
Though this is poetic and nobly written, it is difficult to write a book like this. Yet just like poetry books contain the same kinds of pacing. I couldn't tell you what it was, because it is so varied, but I will say that when you approach writing mechanics, your job as a writer is to find these beats and patterns that make certain patches of dialogue sound the way they do.
So let's look at word economy. That's the first place to start.
Consider this sentence:
"That's not what I mean," Charlie scoffed, shoving his hands into his pockets angrily, storming about like a petulant child.
Everyday I encounter this in my revision of Spirit of Orn, but one of the best things to do in dialogue is to assume that the reader is taking in limited sensory input from your story. Naturally, most people skim when they read. As they do, they are filling in the blanks in their heads and there are ways of taking advantage of this natural thought process. So take a look at the sentence.
The initial statement is the most important, because that is the meat of the sentence. What about the rest though? The natural rhythm of the sentence is something like this:
"STATMENT," Noun verb, adverbial clause.
Now you are probably thinking, "what can I trim?" The statement here is already set up for a complete thought if you just trim the last bit about the character storming about like a child, but think about the sentence a little harder. This can go both ways, but contextually what is more important to give detail about? The act of scoffing is generally something derisive or scornful, so in the context of the statement, shoving hands into pockets gets across the character's demeanor, but the latter bit reveals something about the nature of the character in general.
Look at the sentence with the latter part intact versus the former:
"That's not what I mean," Charlie scoffed, storming about like a petulant child.
"That's not what I mean," Charlie scoffed, shoving his hands into his pockets angrily.
There's so much more power in the first statement than the second. This is all a matter of opinion, but in light of story telling being character driven, I've always found it more effective to express and character through revealing their inner substance rather than collecting this information from their action.
What does this have to do with pacing then? Well there is a natural rhythm you can glean from this kind of editing. Writing mechanics helps to find the rhythm that works best with your story. The above example also helps because when readers scan they are more likely to pickup on dialogue than expository explanation or descriptive prose. Inserting the character's substance into the dialogue allows for a reader to still grasp the inner struggles or emotions of your characters even if they are skimming.
Suffice to say, I could go on for hours. Today was a little more theory driven than normal, but that's the stuff I love the most when writing. Let me know your thoughts! I'm always happy to talk to you guys about the nitty-gritty when it comes to writing.