Gérard TAILLE wrote:That is good news, now all comments goes in the same direction: when japonese resumption is used then the ko ban is lift. It remains only the problem of the number of resumption : how avoiding an infinite number of resumption? My view was to avoid a resumption if a previous one has been occured in exactly the same situation (a loop has been detected) but I see it is a kind a superko and this is not in the spirit of japonese rule. BTW the japonese rule is really able to detect a long loop because this rule is able to conclude to a no result game (triple ko, chosei...).
In practice, at the professional level the number of resumptions is zero. That the question of the number of resumptions arises underscores my sense that the Japanese 1989 rules are not appropriate for amateurs. Let's look at the relevant rules.
Nihon Kiin wrote:Article 7. Life and death
1. Stones are said to be "alive" if they cannot be captured by the opponent, or if capturing them would enable a new stone to be played that the opponent could not capture. Stones which are not alive are said to be "dead."
2. In the confirmation of life and death after the game stops in Article 9, recapturing in the same ko is prohibited. A player whose stone has been captured in a ko may, however, capture in that ko again after passing once for that particular ko capture.
In the case of the 10,000 year ko where the open ko cannot be filled, that stone in the ko mouth is dead. Capturing it does not allow a new stone to be played that the opponent could not capture. End of story. A professional who insisted that that stone is actually alive would lose face badly and be guilty of unsportsmanlike conduct.
Edit: By which I do not mean to imply that a game between two professionals would end in the unfillable ko position. The game would end with the ko filled for seki.
Conceivably, a game between two amateurs could end in such a position, which would be problematic.
pass
pass
tenuki