Beijing-flavored colloquial expression — note the
儿 (érhuà) suffix.
子 here means 'piece / stone' (
棋子, qízǐ, chess piece), and
臭 ('stinky') is gamer slang for 'bad'. By extension you may hear
臭棋 (chòuqí, 'bad chess move / botched play') applied to any clumsy decision in life.