Well, by definition you’re trying to inflict brain damage. Knocking someone out through blunt force is a concussion. The entire point is to damage the brain enough to get it to say, “nope, I need a break now.”
That is assuming you don’t outright kill them. The difference between hitting someone hard enough to annoy them, hard enough to knock them unconscious for a few seconds is… actually, no, there isn’t a difference on your end. It’s all in how their brain and skull decide to interact with one another.
EDIT: There’s also this post from last year.