Reviewing the game, he found he'd played several bad moves.
Tips
culture
臭 (stinky) is colloquially used in Chinese to mean 'bad' or 'lousy' at something - compare 臭脾气 (bad temper) and 臭手 (clumsy hand). 臭棋 carries that same flavor of disgusted criticism.
memory
Picture a chess move so bad it stinks up the board.
