It is in NFBSK because of the word "ball"? I mean, we have pinball, ball room, ball cleaning, etc. I mean, the name of this game is pretty self-explanatory. Like nutcracker.
It's hard to keep track of all the "nasty" things. I mean, Dick used to be a good name for a boy, gay didn't have a homosexual overtone and I was taught that a farmer can have a cock (I literally didn't know the word rooster before I moved over here). My old English dictionary had basically two meanings for "pussy": a) cat, kitten and b) full of puss (yes, a nice word to describe someone's genitalia). And, yes, the f* word was listed there.