The most common mistakes that cost players the most money in poker include playing too many hands out of position, overvaluing medium-strength hands, failing to fold when clearly beat, chasing draws with incorrect
odds, tilting after a bad beat and making emotional decisions,
bluffing in the wrong spots or against players who never fold, neglecting bankroll management, and not adapting to different opponents’ styles. These errors are often repeated, especially by less experienced players, and can quickly turn profitable sessions into losing ones. Awareness, discipline, and experience are key to minimizing these costly habits.