This is all part of the messy aspects of go rulesets that I put in a carboard box and hide in the closet under the stairs. However, there were also some related aspects of procedural rules and go theory that were of some interest to me and, to understand those, ideally I should know the rules of go. But rather than succumb to such electric-shock therapy, I'd like to ask the rules mavens to explain it all to me (in English, not Rulish). In return, they may find the procedural parts are interestingly new to them.
A reminder: Iyama won by 0.5 point after 357 official moves, a record length for Honinbo title matches. Ichiriki could have played on with some more futile ko threats, to extend the moves record, but he apparently preferred not to sully the game record. The video does not show the final stages clearly, so it is hard to be certain what happened then (and it also seems there is a web version of the game where 356 differs from what was played in the game according to the Nihon Ki-in paper record).
First, when Iyama played 357, Takao made a remark expressing surprise that the game finished with Iyama making the last move (and winning). Apparently there is a "well-known fact" that I did not know, to the effect that "in a half-point game the side that fills in the last dame loses." I assume that dame here is being used somewhat loosely (as is common) for the last necessary move. Although the official game record is definitely being quoted by the Nihon Ki-in as 357 moves, there are 7 more dames to fill in for the actual counting to start. That would make 364 moves, meaning White has filled the last dame (in the other sense).
We do know that these extra dames were filled in, however, because when it came to move 362, Ichiriki played the last White stone in his bowl. Iyama played 363 and then Ichiriki put his hand in his empty bowl and wiggled it around. Which Iyama took to mean he was passing. Technically, that meant Iyama had illegally made two moves in succession, which is grounds for a loss. He got away with it here, because the board and stones had been supplied by the local organisers and had not been checked. Apparently - a trivia fact I did not know - the official number of stones is 181 Black stones and 180 White.
There's a bit of gristle in that fillet, but the meaty part for me is the "last dame player loses" heuristic. Does it have any sort of theoretical justification?
But the chocolate souffle for dessert is the piece de resistance. There is apparently a Japanese rule that, sometimes at least, a player does not have to play a repair move in a yose-ko left over at the end of the game. In other words, he gets an extra point profit. And in this case a win! What's that all about?
And why is it being left to me to bring these points up? Shouldn't rules mavens be maving more proactively?
