Is it "centered around" or "centered on"?
Editing grammar for accuracy
The Short Story
The common phrasing error centered around may simply be a confusion of centered (which relates to a fixed location) and revolved (which relates to circular motion, hence revolved around). Or maybe the blame lies with the bullseye, in the center of a round target, many of us imagine when we write about the focal point of something. Instinctual logic associates focus with circles, which have centers and are round. But a circular target is focused on the middle of the bullseye—a specific, central point that helps us get a fix on the circle’s location, yet exists independently of the roundness all around it. Centered on is thus the logical, grammatically accurate phrase.
The Real(ist) Story
Sometimes, editing really does involve simple problems with straightforward answers.
Centered on may refer to the middle point of a literal circular space—on the surface of the earth or on a map, for instance. It may also refer figuratively to the main point of a discussion, the primary focus of a larger effort, or so forth. Either way, the erroneous phrase centered around goes to show we can’t always rely on our instincts when editing. We professional editors spend inordinate amounts of time pondering the mechanics of the written word because we have similar linguistic habits to the rest of humankind. It’s our solemn duty, however, to spot, circumvent, and dismantle the traps those habits set for our writing.
The gist of centered around is clear, but on reconsideration, it suggests that the center of something (a single point) is located within the radius of something. If that were the case, the center of X would be located some distance from the center of X. Centered around isn’t just imprecise; it’s nonsense, or near enough.
If you don’t know (or remember) what a compass is—the tool for drawing circles, not the navigation device—I recommend a quick bit of research. The drawing compass illustrates my point well. (Puns abound. Y’all are welcome.) The foot is placed on a specific point that becomes the center of the circle, so as you rotate the (drawing) arm of the compass, the result is a circle centered on the foot.
Next time you encounter centered around, you can chuckle, shake your head ruefully, correct the mistake, and move on with your editing life.
Story Time
An example from my Vaporous Realms story-world:
Most cartographers in the Redeemed kingdoms centered their maps on the Fledgling World. Their counterparts among the Waveborne more often centered on the Sea of Livyat that lay betwixt the Fledgling and Elder Worlds—and understandably so, because the Nordling and Southron ways of life revolved around the ocean.
Godspeed and happy rewriting!