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counting question

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counting question

Posted: Fri Jan 07, 2011 6:47 am
by entropi
Click Here To Show Diagram Code
[go]$$c L1 and M1 neutral or black?
$$ ---------------------------------------
$$ | . . . . X X O . . O X . O O O . X X X |
$$ | . . . . X O . . . O X X X X X X X O . |
$$ | . . . X X O . . . . O O O X X O O O O |
$$ | . . . X . O . . . O . . O O O X X O . |
$$ | . . . . X O . . . . . O X O X X O O . |
$$ | . . X . X X O . . O O X X X X O O . . |
$$ | . . . X O O . . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]


A game I played recently on OGS. Should L1 and M1 black points or neutral points?

Re: counting question

Posted: Fri Jan 07, 2011 6:49 am
by Li Kao
What make you think that they're neutral? Look like perfectly fine territory to me. If w plays on either of them, b plays on the other, makes a prisoner and the score doesn't change.

On the other hand I'm not sure if w doesn't need 1-2 defensive moves elsewhere/black invasions won't work.

Re: counting question

Posted: Fri Jan 07, 2011 6:51 am
by entropi
Li Kao wrote:What make you think that they're neutral? Look like perfectly fine territory to me. If w plays on either of them, b plays on the other, makes a prisoner and the score doesn't change.


I also think like you but both OGS and SmartGo count them as neutral. Either it is a bug or there is something about the rule set used by OGS.

Re: counting question

Posted: Fri Jan 07, 2011 7:05 am
by Mike Novack
The only way I can see that these might end up as neutral points would be if black lacking enough liberties was forced to connect out to the left. Try possibilities after white plays first at R3 and see if white can be killed fast enough (or no need to connect to end a temporary seki).

Re: counting question

Posted: Fri Jan 07, 2011 7:29 am
by entropi
Mike Novack wrote:The only way I can see that these might end up as neutral points would be if black lacking enough liberties was forced to connect out to the left. Try possibilities after white plays first at R3 and see if white can be killed fast enough (or no need to connect to end a temporary seki).


That's an idea but I cannot imagine the counting engine (if such term exists) of OGS is that clever. It is also not supposed to be that clever.
And on top of that even if it was clever, then it should also count O1 as neutral. But it counts O1 as black territory. So that is not likely to be the case. Probably it's just a bug. Luckily in this game it didn't change the game result.

Re: counting question

Posted: Fri Jan 07, 2011 7:37 am
by topazg
No, it is not that clever, it's a rather interesting scoring bug.

Of course, Black can always take out his frustration elsewhere:

Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . X X O 6 8 O X . O O O . X X X |
$$ | . . . . X O 5 7 . O X X X X X X X O . |
$$ | . . . X X O . . . . O O O X X O O O O |
$$ | . . . X . O . . . O . 2 O O O X X O . |
$$ | . . . . X O 9 . . 4 1 O X O X X O O . |
$$ | . . X . X X O . 3 O O X X X X O O . . |
$$ | . . . X O O . . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]


And the continuations:

Click Here To Show Diagram Code
[go]$$Wc if 5 at 6, then 6 at a
$$ ---------------------------------------
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X O X X . O X X X X X X X O . |
$$ | . . . X X O 3 . . . O O O X X O O O O |
$$ | . . . X . O 2 6 . O . O O O O X X O . |
$$ | . . . . X O X 1 . O X O X O X X O O . |
$$ | . . X . X X O 4 X O O X X X X O O . . |
$$ | . . . X O O 5 . O X X . . . . X O . . |
$$ | . . X O . . a O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]


Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X O X X . O X X X X X X X O . |
$$ | . . . X X O . . . . O O O X X O O O O |
$$ | . . . X . O 1 3 . O . O O O O X X O . |
$$ | . . . . X O X 2 . O X O X O X X O O . |
$$ | . . X . X X O . X O O X X X X O O . . |
$$ | . . . X O O 4 . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]

Re: counting question

Posted: Fri Jan 07, 2011 7:38 am
by Harleqin
I would file a bug report with OGS.

Re: counting question

Posted: Fri Jan 07, 2011 8:01 am
by entropi
But the strange thing is the same bug also exists in SmartGo version 1.4 (rather old, probably from 2004 or so). That's why I thought it could somehow relate to a particularity of a rule-set.

But maybe they use the same software for scoring, or this position is for some reason specificly difficult to program. Anyway I will file a bug report.


@topazg:
At the end I thought about such variations as well. But I was anyway ahead by 7,5 points (due to the bug the game ended by 5,5 points difference) and I thought white would simply give up the stone at m15 by answering l15 at k15.
But if the score was closer and in favour of white, that would surely be something interesting to try.

Re: counting question

Posted: Fri Jan 07, 2011 10:07 am
by Cassandra
entropi wrote:But the strange thing is the same bug also exists in SmartGo version 1.4 (rather old, probably from 2004 or so). That's why I thought it could somehow relate to a particularity of a rule-set.

The current version of SmartGo shows these two points as Black territory.

So a bug report seems necessary for OGS only.

Re: counting question

Posted: Fri Jan 07, 2011 10:43 am
by Stable
topazg wrote:And the continuations:

Click Here To Show Diagram Code
[go]$$Wc if 5 at 6, then 6 at a
$$ ---------------------------------------
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X O X X . O X X X X X X X O . |
$$ | . . . X X O 3 7 . . O O O X X O O O O |
$$ | . . . X b O 2 6 . O . O O O O X X O . |
$$ | . . . . X O X 1 . O X O X O X X O O . |
$$ | . . X . X X O 4 X O O X X X X O O . . |
$$ | . . . X O O 5 . O X X . . . . X O . . |
$$ | . . X O . . a O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]

And after 7? I think b needs to fill at b before this sequence.

Re: counting question + small modifications

Posted: Fri Jan 07, 2011 2:12 pm
by Tommie
Stable wrote:
topazg wrote:And the continuations:

Click Here To Show Diagram Code
[go]$$Wc if 5 at 6, then 6 at a
$$ ---------------------------------------
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X O X X . O X X X X X X X O . |
$$ | . . . X X O 3 7 . . O O O X X O O O O |
$$ | . . . X b O 2 6 . O . O O O O X X O . |
$$ | . . . . X O X 1 . O X O X O X X O O . |
$$ | . . X . X X O 4 X O O X X X X O O . . |
$$ | . . . X O O 5 . O X X . . . . X O . . |
$$ | . . X O . . a O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . . . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ ---------------------------------------[/go]

And after 7? I think b needs to fill at b before this sequence.


First of all, I am convinced that it is good style to start with the smallest threat which works.
(If the smallest threat is denied, then one gets the bigger one(s).
If this here is the last possible endgame sequence, i.e. just before counting, it might not matter though,
as theoretically, W should dispense with that atari-ed single stone and be content with the rest.

Topazg's variant needs a little modification by 'Zwischenzug' and it all works even without 'B'.
'Go is about the order of moves.'

Click Here To Show Diagram Code
[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . X X O 4 6 O X . O O O . X X X |
$$ | . . . . X O 3 5 . O X X X X X X X O . |
$$ | . . . X X O . p 7 8 Q Q Q X X O O O O |
$$ | . . . X b O . . . O . 2 Q Q Q X X O . |
$$ | . . . . X O . . . 0 1 W X Q X X O O . |
$$ | . . X . X X O . 9 @ @ X X X X O O . . |
$$ | . . . X O O . . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . , . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ +---------------------------------------+[/go]

:b1: is the smallest threat, W should abandon :wc: in order to avoid bigger damage.
When B threatens with :b7: , W cannot else then reply with :w8: , i.e. has no time for tesujis (e.g. around P).

Click Here To Show Diagram Code
[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X P X X . O X X X X X X X O . |
$$ | . . . X X P 4 a X O O O O X X O O O O |
$$ | . . . X . P 3 5 . O . O O O O X X O . |
$$ | . . . . X P 1 2 . O X O X O X X O O . |
$$ | . . X . X X O . X O O X X X X O O . . |
$$ | . . . X O O . . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . , . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ +---------------------------------------+[/go]

After :b5: , W cannot double-atari at A, because that would also be auto-atari.

Re: counting question + small modifications

Posted: Fri Jan 07, 2011 3:10 pm
by DrStraw
Tommie wrote:
Click Here To Show Diagram Code
[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X P X X . O X X X X X X X O . |
$$ | . . . X X P 4 a X O O O O X X O O O O |
$$ | . . . X . P 3 5 . O . O O O O X X O . |
$$ | . . . . X P 1 2 . O X O X O X X O O . |
$$ | . . X . X X O . X O O X X X X O O . . |
$$ | . . . X O O . . O X X . . . . X O . . |
$$ | . . X O . . . O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . , . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ +---------------------------------------+[/go]

After :b5: , W cannot double-atari at A, because that would also be auto-atari.


True, but he can play J16.

Re: counting question + small modifications

Posted: Fri Jan 07, 2011 3:31 pm
by Li Kao
But I think even after J16 black gains something:
Click Here To Show Diagram Code
[go]$$Wc
$$ +---------------------------------------+
$$ | . . . . X X O O O O X . O O O . X X X |
$$ | . . . . X O X X . O X X X X X X X O . |
$$ | . . . X X O O . X O O O O X X O O O O |
$$ | . . . X . O X X 1 O . O O O O X X O . |
$$ | . . . . X O X O 5 O X O X O X X O O . |
$$ | . . X . X X O 3 X O O X X X X O O . . |
$$ | . . . X O O 2 . O X X . . . . X O . . |
$$ | . . X O 6 . 4 O O X . . . . . X O . . |
$$ | . . X O . . O X X X . . . . . X O . . |
$$ | . X X O X . O X . , . . X X X O O . . |
$$ | X X O O . . O O X X X X X O O X . . . |
$$ | O X X O . . O X X X O X O . . . . . . |
$$ | O . . O . O O O O X O O O . . . . . . |
$$ | . O O . . O O X O X O X O O O O O O . |
$$ | O X O . . O X X X O O X O X O X X O O |
$$ | . X O O O O X . X , . X X X X X . X X |
$$ | X . X X O X O O X O O O O X . . . . . |
$$ | X . X . X X X . X O X X O X . . . . . |
$$ | . X . X . X . . . X . . X . . . . . . |
$$ +---------------------------------------+[/go]
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