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| scoring eyes in seki question http://www.lifein19x19.com/viewtopic.php?f=45&t=8990 |
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| Author: | xed_over [ Wed Aug 28, 2013 9:47 pm ] |
| Post subject: | scoring eyes in seki question |
As I understand it, under traditional Japanese rules, eye's in seki are not counted. However in this position from a recent game, it appears white has two real eyes. One is what appears to be a "false" eye, but since black can't force white to fill it, then is white's group considered to be independently alive, so white's two points count and black's one doesn't? Is that the correct way to score this using traditional Japanese rules? |
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| Author: | Kirby [ Wed Aug 28, 2013 10:21 pm ] |
| Post subject: | Re: scoring eyes in seki question |
There are different versions of Japanese rules, but I think they're in agreement in this regard: stones in seki don't have points for the eyes. See Diagram 15 from this page: http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html Quote: In the position in Diagram 15, the black and white groups are both alive, but in seki because of the dame at A, so neither side has any territory. A move at A is needed to make Black's and White's eyes into territory. In the case of your diagram, since the dame is not filled, the groups are in seki, and neither side has points for the eyes. Here's a link to some "more official" text: http://www.nihonkiin.or.jp/joho/kiyaku/kiyaku08.htm Bottom picture is similar situation, and still, no points. |
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| Author: | xed_over [ Wed Aug 28, 2013 10:40 pm ] |
| Post subject: | Re: scoring eyes in seki question |
Kirby wrote: There are different versions of Japanese rules, but I think they're in agreement in this regard: stones in seki don't have points for the eyes. See Diagram 15 from this page: http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html Quote: In the position in Diagram 15, the black and white groups are both alive, but in seki because of the dame at A, so neither side has any territory. A move at A is needed to make Black's and White's eyes into territory. In the case of your diagram, since the dame is not filled, the groups are in seki, and neither side has points for the eyes. but that diagram doesn't make any sense to me. either side could fill the dame without loss because neither group is capturable. there must be a typo in that diagram, no? |
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| Author: | macelee [ Wed Aug 28, 2013 10:44 pm ] |
| Post subject: | Re: scoring eyes in seki question |
Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the  stone removed from the seki and count as a dead stone?
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| Author: | snorri [ Wed Aug 28, 2013 11:10 pm ] |
| Post subject: | Re: scoring eyes in seki question |
macelee wrote: Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the stone removed from the seki and count as a dead stone?Since white can capture in hypothetical play, white doesn't need to play a move to capture it. It would be removed from the board during scoring, the same way that  would be. The fact that this is in a seki doesn't change that. My informal sense of Japanese rules is that in the original position there are no points in the seki.
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| Author: | Kirby [ Wed Aug 28, 2013 11:15 pm ] |
| Post subject: | Re: scoring eyes in seki question |
macelee wrote: Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the stone removed from the seki and count as a dead stone?My interpretation is that you must actually remove the stone to get the point, just like you must play the dame in the example I gave in order to get points. |
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| Author: | xed_over [ Wed Aug 28, 2013 11:25 pm ] |
| Post subject: | Re: scoring eyes in seki question |
Kirby wrote: macelee wrote: Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the stone removed from the seki and count as a dead stone?My interpretation is that you must actually remove the stone to get the point, just like you must play the dame in the example I gave in order to get points. Yeah, but according to the links you shared earlier, the rules say that the stones can't be removed. They must stay on the board and not counted. http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html diagram 17 its really bizarre. I didn't know all this about Japanese rules. I'm really starting to like AGA rules even more. |
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| Author: | Kirby [ Wed Aug 28, 2013 11:39 pm ] |
| Post subject: | Re: scoring eyes in seki question |
xed_over wrote: Kirby wrote: macelee wrote: Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the stone removed from the seki and count as a dead stone?My interpretation is that you must actually remove the stone to get the point, just like you must play the dame in the example I gave in order to get points. Yeah, but according to the links you shared earlier, the rules say that the stones can't be removed. They must stay on the board and not counted. http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html diagram 17 its really bizarre. I didn't know all this about Japanese rules. I'm really starting to like AGA rules even more. No, that's in line with what I'm saying: Quote: Note: Before the end of the game, White can play A to capture the two black stones, then capture another stone which Black has to throw in. You can get the points, but you must play to capture them. |
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| Author: | RobertJasiek [ Thu Aug 29, 2013 4:03 am ] |
| Post subject: | Re: scoring eyes in seki question |
http://home.snafu.de/jasiek/j1989c.html http://home.snafu.de/jasiek/j_verbal_status.pdf |
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| Author: | asura [ Thu Aug 29, 2013 4:29 am ] |
| Post subject: | Re: scoring eyes in seki question |
xed_over wrote: Kirby wrote: macelee wrote: Slightly modifying the original diagram. This is again a seki. Whether or not capturing the black stone at 'a' should not matter. But if white does, it gains extra points in Japanese rule. How reasonable is that? My question is: in a real game, is the stone removed from the seki and count as a dead stone?My interpretation is that you must actually remove the stone to get the point, just like you must play the dame in the example I gave in order to get points. Yeah, but according to the links you shared earlier, the rules say that the stones can't be removed. They must stay on the board and not counted. http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html diagram 17 its really bizarre. I didn't know all this about Japanese rules. I'm really starting to like AGA rules even more. It's not a big issue, because in Japananese rules you can request resumtion if you forget to capture "dead" stones in a seki. The opponent cannot gain anything when he insists the stone is no prisoner, so he might as well agree. The same applies to seki caused by forgotten dame. |
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| Author: | Dusk Eagle [ Thu Aug 29, 2013 8:24 am ] |
| Post subject: | Re: scoring eyes in seki question |
Japanese rules in the book are different from Japanese rules often applied in practice. In practice, you don't have to fill all the dame or capture dead stones in seki. However, if a rule dispute occurs then you can resume the game and complete the position according to the rules before applying the rulebook to interpret a situation. |
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| Author: | RobertJasiek [ Thu Aug 29, 2013 9:24 am ] |
| Post subject: | Re: scoring eyes in seki question |
Dusk Eagle wrote: In practice, you don't have to fill all the dame For the sake of simplicity, let us stick to the two-sided dame. Practice differs for real world go played under the Japanese 1989 Rules (dame filling can affect the score, if the rules are applied strictly), real world go played under the World Amateur Go Championship Rules (dame filling is required), real world go played under variants of verbal Japanese rules (usually, dame filling is a custom, but the exact timing and nature varies; at the end of counting and before announcing the score, the dame should be filled), online go with Japanese server rules allowing unfilled dame (dame filling is voluntary, but - in case of especially KGS - is recommended so that server scoring mistakes do not occur and affect the score), online go with Japanese server rules requiring dame filling. Tournament rules might prescribe alternate dame filling. Conclusion: depending on the place of play, the used version of Japanese rules and any used server, filling two-sided dame is or is not mandatory and is or is not relevant for the score. |
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| Author: | xed_over [ Thu Aug 29, 2013 9:30 am ] |
| Post subject: | Re: scoring eyes in seki question |
So then, back to the original question.. There's never a case where some set of eyes in seki would count as points? In practice, or theory? I think in practice (irregardless of the actual rules), we would count the eyes in diagram 15 above, and not even call that a seki, right? But in my original position, its a true seki and none of the eyes are counted then? |
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| Author: | RobertJasiek [ Thu Aug 29, 2013 9:38 am ] |
| Post subject: | Re: scoring eyes in seki question |
Under traditional Japanese rules, right. Under quite a few (but not all) server Japanese rules, wrong. |
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| Author: | oren [ Thu Aug 29, 2013 9:47 am ] |
| Post subject: | Re: scoring eyes in seki question |
xed_over wrote: But in my original position, its a true seki and none of the eyes are counted then? Yes. 
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| Author: | Dusk Eagle [ Thu Aug 29, 2013 11:36 am ] |
| Post subject: | Re: scoring eyes in seki question |
Yes, the original position is just a seki. No points for either side. |
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| Author: | Dusk Eagle [ Thu Aug 29, 2013 11:46 am ] |
| Post subject: | Re: scoring eyes in seki question |
RobertJasiek wrote: Dusk Eagle wrote: In practice, you don't have to fill all the dame For the sake of simplicity, let us stick to the two-sided dame. Practice differs for real world go played under the Japanese 1989 Rules (dame filling can affect the score, if the rules are applied strictly), real world go played under the World Amateur Go Championship Rules (dame filling is required), real world go played under variants of verbal Japanese rules (usually, dame filling is a custom, but the exact timing and nature varies; at the end of counting and before announcing the score, the dame should be filled), online go with Japanese server rules allowing unfilled dame (dame filling is voluntary, but - in case of especially KGS - is recommended so that server scoring mistakes do not occur and affect the score), online go with Japanese server rules requiring dame filling. Tournament rules might prescribe alternate dame filling. Conclusion: depending on the place of play, the used version of Japanese rules and any used server, filling two-sided dame is or is not mandatory and is or is not relevant for the score. I agree with what you've said I think. The point I was trying to make is that in the cases where the dame aren't filled before passing and it does somehow affect the score, (e.g. someone insists on a "any adjacent dame" interpretation of seki,) the game can be resumed and all of the dame can be filled. |
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| Author: | RobertJasiek [ Thu Aug 29, 2013 12:27 pm ] |
| Post subject: | Re: scoring eyes in seki question |
Resumption is possible AFTER game-stopping passing and BEFORE the game end:) |
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| Author: | Mef [ Thu Sep 05, 2013 7:04 pm ] |
| Post subject: | Re: scoring eyes in seki question |
xed_over wrote: So then, back to the original question.. There's never a case where some set of eyes in seki would count as points? In practice, or theory? I think in practice (irregardless of the actual rules), we would count the eyes in diagram 15 above, and not even call that a seki, right? But in my original position, its a true seki and none of the eyes are counted then? Strictly speaking, you should not count the points unless someone is willing to fill the dame. It is incredibly rare, but there are situations where groups with two eyes make a seki. Imagine this --There is a ko somewhere else on the board white can start, but white's threat with the atari is not large enough to win. If black plays the final dame, black will give white a threat (because now the corner threat is 2 points larger than if white filled the dame!). Black will not play because it gives white a ko threat. White on the other hand stands to gain 1 point by not playing the dame, because he loses 2 point in the seki to black's 3. If neither player can play the dame without taking a loss, it is a seki. |
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| Author: | RobertJasiek [ Thu Sep 05, 2013 10:33 pm ] |
| Post subject: | Re: scoring eyes in seki question |
Interesting... can you also construct such a position? |
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