"EricBackus","Rules Question about Seki","2008-05-25 14:20:07","First off, yes, I do know what seki is and how it is normally scored. This question is about how to score a particular corner case. Suppose we have the following position: \ \ Seki with \"dead\" stone in eye \ [go] \ $$--------- \ $$|O.X.OXO. \ $$|.OXXXXO. \ $$|XXOOOOO. \ $$|.XO..... \ $$|XXO..... \ $$|OOO..... \ $$|........ \ [/go] \ \ \ The above is a variation on a classic corner seki position. In this variation, there is an extra white stone inside one of the black eyes. \ \ During the game, black could capture the white stone that is in the eye. But, suppose black doesn't do this. How is this position scored? \ \ In Japanese rules, we normally think there are no points in seki. But here, you can argue that the white stone is dead and should be removed, giving black 1 point. On the other hand, in a recent tournament that I played in, the equivalent of this position came up and we were told that there are literally no points in seki, so black gets no points for the stone. Which means, black should have captured the stone during the game, to get one additional point. \ \ In Chinese rules, I assume that there is no controversy here - black has a total of 14 points of stones + territory, while white has 2 points in the seki plus whatever for the border outside the seki. \ \ What is the correct way to score this in Japanese rules? In AGA rules? In Chinese rules? \ \ Thanks for any help you can provide. \ \ -- \ Eric" "erislover","","2008-05-25 15:24:56","Black will just capture the stone before passing to collect the point." "Sverre","","2008-05-25 16:41:43","Under Japanese you have to actually capture the stone to get the point, I dunno if you are allowed to resume play after two passes just to capture the thing if you forgot, but unless it's in a tournament your opponent will likely allow this. Under KGS rules you can go back to capture, I think. Pretty much any other ruleset lets you count points in a seki so it's not an issue." "Bill Spight","","2008-05-25 20:58:06","Under Japanese '89 rules the dead White stones may not be removed without capture. Black can capture before passing or reopen play after two passes but before agreement about the score. If Black reopens play, White plays first, but White has nothing better here than a pass, and then Black can take the White stone. \ \ Under Lasker-Maas or Spight territory rules, Black can capture the stone during the encore for 2 points net instead of 1. (Under Lasker-Maas Black can capture with a prisoner, reducing her prisoner count by 1; under Spight rules Black will get a pass stone from White.)" "Sverre","","2008-05-25 21:09:44","[QUOTE=Bill Spight]Under Lasker-Maas or Spight territory rules, Black can capture the stone during the encore for 2 points net instead of 1. (Under Lasker-Maas Black can capture with a prisoner, reducing her prisoner count by 1; under Spight rules Black will get a pass stone from White.)[/QUOTE] \ \ I don't know much about various rulesets, so forgive me if I'm asking a silly question: would the same be the case for asymmetric dame (ie. Black gaining a point under Spight or Lasker-Maas rules due to prisoner recovery or pass stone)?" "Bill Spight","","2008-05-25 21:54:46","[QUOTE=Sverre]I don't know much about various rulesets, so forgive me if I'm asking a silly question: would the same be the case for asymmetric dame (ie. Black gaining a point under Spight or Lasker-Maas rules due to prisoner recovery or pass stone)?[/QUOTE] \ \ Yes, it's not a bug, it's a feature. ;) \ \ As far as knowing about those rule sets, AFAIK, nobody plays by them, anyway. Button Go, anyone? ;)" "EricBackus","Thanks!","2008-05-25 22:21:15","[QUOTE=Sverre]Under Japanese you have to actually capture the stone to get the point[/QUOTE] \ [QUOTE=Bill Spight]Under Japanese '89 rules the dead White stones may not be removed without capture. Black can capture before passing or reopen play after two passes but before agreement about the score. If Black reopens play, White plays first, but White has nothing better here than a pass, and then Black can take the White stone.[/QUOTE] \ \ Thank you Sverre and Bill, this is exactly what I was looking for. I find it quite surprising, actually; this is the only place I'm aware of where Japanese rules force you to actually capture a stone which is unquestionably dead." "sol.ch","","2008-05-25 22:24:05","I had no idea about this force-capture seki business...thanks for the heads up." "Bill Spight","","2008-05-25 23:49:44","[QUOTE=EricBackus]Thank you Sverre and Bill, this is exactly what I was looking for. I find it quite surprising, actually; this is the only place I'm aware of where Japanese rules force you to actually capture a stone which is unquestionably dead.[/QUOTE] \ \ Actually, in a double ko seki, the two stones in atari are dead, but are not removed, either. And there is a new kind of beast, the anti-seki (not an official term), in which stones are dead but are not removed. You can get an anti-seki by leaving a ko unresolved. the 1949 rules mandated resolving the kos, but were criticized for not be [I]logical[/I], and it was unclear whether certain kos needed to be filled. The anti-seki provisions of the 1989 rules do not mandate resolving certain kos, but the penalty is not getting territory. Logical but bizarre. ;)"