Dear Tic-Tac-Toe Players,
Growing up, I was a big fan of tic-tac-toe until my brothers and I became skilled enough that the game would almost always result in a tie. I have distinct memories of writing CAT above those tie games.
Where did CAT come from? Why do we write it there? Is it an acronym of some kind?
Y'all are amazing,
Who wasn't a big fan of tic-tac-toe growing up? I mean really. It got me through so many car trips.
I know what you're talking about, and I used to call those "cat's games." Apparently it's a common enough phrase that people have enquired over at Quora, our greatest rival as a question answering service, and this answer gives some plausible explanations. In case you're morally opposed to clicking on links, it explains that a Tic-Tac-Toe tie could be called a cat's game because it's similar to a cat chasing its own tail: it can't ever win, so the whole thing is a pointless, if enjoyable, exercise. It could also be because apparently a tie in Tic-Tac-Toe is called a scratch, and cats scratch things.
According to this stackexchange, people have been calling it a cat's game ever since at least the early 1950s, so by this point it's probably carried on by tradition more than anything. That thread also has some additional suggestions about the etymology of the phrase, but the most common consensus seems to be the one about cats chasing their tails.