Is it that unusual? I’m not sure. Elmore’s characters tell you their thoughts and feelings and projections. The distinction Westlake sees, I think, is between that technique and the authors who tell you what the character’s thoughts, feelings, etc., are.
Elmore might write something like, “the man feeling pain now, a burning that was like a hot wire through raw nerves.” Whereas your average writer might express the same idea as, “he felt pain in the place where the bullet had gone through his arm. It made him think of what a hot wire might feel like.”
The key to the difference, besides Elmore’s genius for eliminating all non-essential words, is the use of the gerund form, which makes more seamless, sometimes eliminates, the gap between character and reader. With Elmore, the reader is inside the skin of the character, feeling what he feels, seeing what he sees. With other writers, you’re aware of being told those things by the author. It’s that awareness that takes you out of the story—what Elmore calls the author poking his nose in, not being invisible—with the result that the reader becomes less engaged, sometimes disengaged, from the story.
Here’s an example of the three levels Westlake saw (IMO), taken in sequence from City Primeval:
1) description: “Clement’s little-boy face looked red and swollen; his breath smelled of sour-mash whiskey.”
2) dialogue: “The Wildman all tuckered out? You big shit, where’d you go?”
3) 3rd level: “Clement opened his eyes, blinked a few times to focus, seeing noon sunlight in the window and Sandy’s frizzy hair sticking out golden from the pillow.”
In the 3rd level example, the sentence begins with the author giving a description. The magic happens with the transition from past tense to the gerund form, Elmore using “seeing” instead of “and saw.”
The critical difference is that with the past tense form, you have an extra, unnecessary player, the author, who’s telling you what Clement saw. With Elmore’s gerund form, however, the author is eliminated and the reader sees through Clement’s eyes. Now there are two players, Clement and the reader, becoming almost as one, with the reader feeling like he’s inside Clement’s head, like the two have merged and have only one perspective—i.e., what the character sees or feels or thinks, etc..
I look back at the books and movies and music and even art that I’ve loved the most, that minute percentage that stands far above the rest, and the common thread is immersion in the story, losing the awareness that I’m reading a book or watching a movie, something that was created by a third party. The magic is in the merger.
It’s one thing to know that, but it’s quite another to implement it, to write as Elmore writes. Thus his genius, or an element of it. We could get into what other things go into it—the authentic sounding dialogue, using dialogue to carry the story, the humor, the tension, the attitudes of the disparate characters—but maybe that’s something that should be taken up on a separate thread.