Etiquette and Rules
Both the rules and sportsmanship should be applied at the same time and by each player.
How is this possible? Applying both means to apply the rules and means to apply sportsmanship. Applying both at the same time means that applying the rules does not prohibit applying sportsmanship and that applying sportsmanship does not prohibit applying the rules. Application by each player means that a player does not expect something from his opponent that he does not expect from himself, too.
If this is so clear, then why are there hot discussions about different ethics expressed by different players? Such can arise if the rules shall be applied but not sportsmanship, if sportsmanship shall be applied but not the rules, if neither the rules nor sportsmanship shall be applied, if the rules are so difficult that their application is difficult, if perception of sportsmanship is so different for different persons that somebody's application of sportsmanship violates someone else's sense of sportsmanship or vice versa, or if a player expects something from his opponent that he does not also expect from himself.
Ruleset. It has been a bad tradition to use difficult rules, which can lead to different interpretations of their correct application easily. It has been another questionable tradition to see a conflict between the rules and sportsmanship. Instead both should be applied. This is much easier for everybody if the rules are or become clear. For clear rules, varying perceptions of sportsmanship are close to each other. For difficult rules, varying perceptions of sportsmanship can differ considerably easily. E.g., if the rules let each dame be worth 1 point or if they require filling of dame that do not kill oneself before scoring, then sportsmanship of unfilled dame simply does not become an issue; i.e. there is no conflict between the rules and sportsmanship any longer.
Resigning. Some call it a bad habit not to resign in a lost position. They should ask themselves whether they do always resign if they are at least 1 point behind. Resignation is a right of the player; it is not a right of the opponent to force a player to resign.
First move location. Some call it a bad habit not to place the first stone in the lower part of the upper right corner viewed from the moving player. They should ask themselves whether it is sportsmanlike to disturb the player by pointing this out. It is a right to choose the intersection of play; it is not the opponent's right to choose the player's intersection of play. If a player shall respect that the opponent plays his first move in a particular part of the board, then the opponent should also respect it if the player does not play his first move in a particular part of the board.
- Bignose: In counterpoint to this, there are many people who enjoy learning Go as much for the cultural flavour as for the rules. Informing someone new to the game why their first move might be considered poor etiquette (and thus giving a cultural nuance to their nascent learning of the game) is quite different to interrupting a tournament game to insist the first move be played elsewhere (when they almost certainly know the tradition already, and it's quite irrelevant).
All those traditions may be entertaining for people loving tradition. However, it is not the right of an opponent to require a player to follow such traditions. Likewise, it is not the right of a player to require his opponent not to follow such traditions.
Sportsmanship is not the requirement to violate the rules but is a context beyond application of the rules so that one's opponent is respected as a human being quite like the opponent respects the player as a human being. E.g., like you do not kill another human being to get his money, you do not kill your opponent to win the game (even if a Chinese tale reports such an incident once). Less drastically, like you do not let your mobile phone ring in a music event, you do not let it ring during a tournament game.