The app for independent voices
I believe this is the more common variation:
A man and a dog are playing chess
A woman walks in and says "holy crap, your dog can play chess?! That's amazing! What a brilliant dog! "
The man says "you think my dog is brilliant? Pffft. Hardly. He's pretty dumb, I've won 19 games out of the 20 we've played."
(At the risk of ruining the joke by explaining it, I think my version is superior. The more common version sets up the foil of a man who’s too dumb to realize that a) a dog who could win at chess is impressive and b) losing at chess to a dog is embarassing. My joke however has another layer because it further emphasizes the absurdity in which the man fixates on a minor aspect of the dog’s play instead of the impressiveness of a dog that can play chess at all.
Further, avid chessplayers might note that the queen’s gambit accepted is a perfectly valid, albeit controversial, opening line, so the man’s objection falls even on his own terms. So the joke is funny for people who don’t know anything about chess other than that it’s a board game but even funnier for people who do).