I suppose this room is came out of this:

BTW quite a few jokes can be found in the post on the main site: Do good math jokes exist?

@joro I did not understand that one. At first I thought that it is because my poor English, so I have asked at ELL. But it's possible that it's mistranslated.

I suppose it's supposed to be this one:

> In a park people come across a man playing chess against a dog. They are astonished and say: "What a clever dog!" But the man protests: "No, no, he isn't that clever. I'm leading by three games to one!"

@MartinSleziak Your version is significantly better and the main idea is the same. I am translating most of these from Bulgarian and very likely I make language mistakes.

(hm, is this intended for jokes or for math jokes?)