To be a good sportsman, one must be a stoic and never show rancor in defeat, or triumph in victory, or irritation, no matter what annoyance is encountered. One who can not help sulking, or explaining, or protesting when the loser, or exulting when the winner, has no right to take part in games or contests.
Emily Post (2007). “Etiquette: In Society, in Business, in Politics and at Home”, p.529, Cosimo, Inc.