In the movie, wasn't he playing blackjack when this happened? Like, the antagonist has 17, and then hits even though it's risky, but still wins. Austin only has 5, but says this and chooses to stay anyway, despite being guaranteed a loss.
I know of course that memes' contexts often change over time. But it seems like considering it's a direct reference to another card game there should be a close Dominion analogy. My brain is too fried from work though to think of anything funny right now haha