Tilt
Playing worse because you’re upset. The most expensive word in poker.
You raise pocket kings from the cutoff, the big blind calls, and the flop comes nine-four-two rainbow. You bet, get check-raised, and stack off with your overpair. The big blind flips 9-4 offsuit for two pair, having called out of position on a hunch. The money's in, and your kings are drawing to two outs. Two hands later you pick up queens under the gun and, still stinging, jam 40 big blinds preflop instead of a standard raise — into a table that hasn't three-bet you all night. The cards didn't change the math on those queens. Your head did.
That swing is why tilt is the biggest leak in most players' games. A bad beat doesn't change your equity, but it can push you into bigger bluffs, thinner calls, and looser ranges than your game allows. Good regulars spot a tilted player within a few hands and adjust — three-betting lighter, calling down wider — because tilt turns a solid opponent into a predictable one. The beat costs you a stack. The tilt that follows can cost several more.
The common mistake is treating tilt as a mood to push through instead of a signal to stop. You try to get even in the same session, chasing the loss with more hands and bigger pots instead of leaving. The fix is simple: stand up and walk. But it only works if you catch the tilt before it catches your stack.