Well, shall we complicate things?
Sock
1. Comedy, the comic drama, comic acting--A term derived from the Latin soccus, a light, low, soft shoe worn in ancient Greek and Roman comic acting.
2. A tremendously successful show, performer, etc. Hence a sock hit.+ Also as +socko, sokko.
Theatre language: a dictionary of terms in English of the drama and stage from medieval to modern times. Theatre Arts Books, 1961 - 428 pages
The shoe existed, and is the origin of "sock," the thing that goes under shoes. Oxford:
>soccus, the low-heeled, loose-fitting shoe worn by Roman actors of comedy, of Greek origin. The word is often used to symbolize comedy; the poet Milton speaks of ‘Johnson's learned sock’.
I'm not buying it. I think the idea that some performance was so good that it socked you between the eyes, works better. "Sock" as a verb meaning "to hit" dates to at least 1700 and the origin is unknown, although there are speculations.