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Re: Status question : is this a bent four in the corner?
Posted: Tue Oct 30, 2012 9:02 am
by Bill Spight
Magicwand wrote:Robert. Are you saying that white Ko stone is dead by rule? Even if their aren't any dame?
Under the Japanese '89 rules the White ko stone is dead because Black can take and win the ko without giving rise to another uncapturable White stone. It is not removed because it is not within Black's territory.
The Japanese '89 rules are strange.

Re: Status question : is this a bent four in the corner?
Posted: Tue Oct 30, 2012 9:45 am
by RobertJasiek
Magicwand wrote: Are you saying that white Ko stone is dead by rule? Even if their aren't any dame?
After your edit, replacing Korean by Ko, let me answer also your now new question:
The ko stone is dead as a consequence of the rules' definitions and their application to that stone (as explained earlier). Dame are, according to the rules, identified after life and death have already been identified. If you have too much time, see also:
http://www.cs.cmu.edu/%7Ewjh/go/rules/Japanese.html
http://home.snafu.de/jasiek/j1989c.html
http://home.snafu.de/jasiek/j2003.html
http://home.snafu.de/jasiek/j2003inf.html
http://home.snafu.de/jasiek/j2003com.html
Re: Status question : is this a bent four in the corner?
Posted: Tue Oct 30, 2012 9:58 am
by mitsun
Bill Spight wrote:
Under the Japanese '89 rules the White ko stone is dead because Black can take and win the ko without giving rise to another uncapturable White stone. It is not removed because it is not within Black's territory.
The Japanese '89 rules are strange.

$$
$$ ------------------
$$ | W X X . O X .
$$ | . O . O O X .
$$ | O O O O X X .
$$ | X X X X X . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ ------------------
$$ | W X X . O X .
$$ | . O . O O X .
$$ | O O O O X X .
$$ | X X X X X . .
$$ | . . . . . . .[/go]
If W does not intend to start and win the ko, then the marked move seems like a mistake. In an actual game, why would there be any scoring controversy? Instead of passing, B can capture the W stone and then fill the ko, gaining one point for the prisoner, which is removed from the board. Under area scoring rules, I suppose B also gets points for the dame he fills, and he can wait until there are no other dame on the board to get these points while W passes. Unless W has an inexhaustible supply of ko threats, W cannot prevent this outcome. Am I missing something?