So often I see ads from book editors that proclaim “Editor of (fill in a number) New York Times bestsellers!” Here’s why most of the time, that’s just hype.
Book editors at publishing houses are mostly in acquisitions. That means they acquire books by finding stuff in the slush pile then bringing it forward for consideration among other acquisitions editors, the marketing department, etc. etc. They’re good at finding quality.
Note that: finding quality. Not making quality.
If a project is too rough or just isn’t to their taste, they pass. And they pass a lot.
What they do select out of the submissions pile tend to be already fairly strong. The editing they might do usually is pretty nominal…tweak a personality trait here, change the order of events there.
They don’t do a lot because they don’t have time to do a lot. It’s fairly rare these days for publisher’s editors, who are skilled in acquisition, to do much actual editing.
There are exceptions, of course, but that also isn’t common.
So, “editor of X NYT bestsellers” might mean they said, “Hey, author, chapter one drags too much. Please rewrite it.”
Or, “Hey, author, so-and-so’s dialogue is stilted. Please adjust.”
Or, “Hey, author, I’m (or more likely, my freelance copyeditor is) going to do a little polishing on your project to make everything pretty.”
So beware too much of that NYT bestseller hype. Most of the time, it doesn’t mean what you think it means.