Thesis Gamesmanship that breaks no rule is still a form of cheating
Its coordinates: 6.25 Philosophy of Sport and Play · 6.27 Philosophy of Humour
Where it stands
Thesis: gamesmanship, winning by tactics that break no rule but undermine the contest, is a form of cheating, not merely bad manners.
Thirty years of coaching under-16 rugby gave me a long list. Faking an injury to break the other side's momentum. Walking slowly to the line-out when you're ahead. A quiet word in a nervous kicker's ear. None of it is against the laws. In 1947 Stephen Potter wrote a comic book about it, The Theory and Practice of Gamesmanship, or the Art of Winning Games without Actually Cheating. The subtitle is the whole debate.
Bernard Suits defined playing a game as the voluntary attempt to overcome unnecessary obstacles. You accept the rules because they create the challenge you have chosen to face. If that is right, a player who keeps the letter of the rules while dodging the challenge they create has not really played, any more than a cheat has.
Against: if it isn't in the rules, it's part of the game. Composure under provocation is a skill like tackling, and "the spirit of the game" is just whatever the winning side's coach dislikes.
I've argued this with boys for decades. Mark your side.