Browsing through some blogs this week, I came across this description of a truck redesign: “Although the cargo bed and chassis were carryovers from previous models, the Champ cab was an all new design based off the Lark…”
Well, no. The new design wasn’t “based off” anything. It was based on the Lark. This is what happens when writers grab at phrases without thinking them through. A base is something solid that supports your new project. Without it, your project wobbles and falls. When you put your project on a base, you are basing your project.
What is the base for the Champ cab design? It is the Lark. The new design is based on the Lark.
If you insist on using “off” in some fashion, you could say that the designers took the front end off the Lark and placed it on the Champ chassis. Or, to condense the language a bit, the new truck cab is a takeoff.
“Based off” is not the only mix-and-match phrase out there. You’ll see the same shenanigans when a writer says something is “centered around” something else. Again, all you have to do is think about the words for a minute. The center of anything is a point. Everything else can be arranged around the center, but the center itself can’t be around anything else. All the other elements are centered on a particular point.
“Off,” “on,” and “around” are fundamental spatial relationships. Toddlers learn about them from “Sesame Street.” You could even say they are basic. So base your writing on them.