Life In 19x19

Schachus wrote:So lets say I have this position at game end:

$$W
$$ . . . . . . |
$$ . . X X X X |
$$ . . X O O O |
$$ . X . O . X |
$$ . X X O X X |
$$ . . X O X X |
$$ -------------

Click Here To Show Diagram Code

[go]$$W
$$ . . . . . . |
$$ . . X X X X |
$$ . . X O O O |
$$ . X . O . X |
$$ . X X O X X |
$$ . . X O X X |
$$ -------------[/go]

and white for some reason claims my stones were dead, becuase he can capture it. What would be the right way to answer this by the rules. Do I need to say "yes they are, but so is your group?"

The "..." in my posting above -- referring to Article 7.1 -- reads:

", or if capturing them would enable a new stone to be played that the opponent could not capture."

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[go]$$W
$$ . . . . . . |
$$ . . X X X X |
$$ . . X O O O |
$$ . X . O 1 X |
$$ . X X O X X |
$$ . . X O X X |
$$ -------------[/go]

Click Here To Show Diagram Code

[go]$$W
$$ . . . . . . |
$$ . . X X X X |
$$ . . X O O O |
$$ . X . O O . |
$$ . X X O . 2 |
$$ . . X O . . |
$$ -------------[/go]

Click Here To Show Diagram Code

[go]$$W
$$ . . . . . . |
$$ . . X X X X |
$$ . . X O O O |
$$ . X 4 O O 3 |
$$ . X X O 5 X |
$$ . . X O 6 . |
$$ -------------[/go]

This implies that Black's five stones in the corner are "alive".

As you will know for sure, White's group can be captured by Black, so her stones are "dead".

For details of the Japanese 1989 Rules, see
http://home.snafu.de/jasiek/j1989c.html

Schachus wrote:Maybe this is the time to ask this stupid question:
I never understood how this rule translates to the rule we know.

if there is a dead white shape with a black nakade then usually the nakade stones CAN be "caputed", but somehow it doesnt make a difference, because there in white territory anyway after taking black stones. How is that inside the rules?.

So lets say I have this position at game end:

$$W
$$ . . . . . .
$$ . . . . . .
$$ . . X X X X
$$ . . X O O O
$$ . X . O . X
$$ . X X O X X
$$ . . X O X X
$$ -----------

Click Here To Show Diagram Code

[go]$$W
$$ . . . . . .
$$ . . . . . .
$$ . . X X X X
$$ . . X O O O
$$ . X . O . X
$$ . X X O X X
$$ . . X O X X
$$ -----------[/go]

and white for some reason claims my stones were dead, becuase he can capture it. What would be the right way to answer this by the rules. Do I need to say "yes they are, but so is your group?"

Good question!

The more complete rule is: Stones are dead if they can be captured, and the owner cannot then get living stones on the same intersections by continuing play.

A simple example is snapback:

Click Here To Show Diagram Code

[go]$$B
$$ X X X X
$$ X O O X
$$ O B . X
$$ O O X X[/go]

Even though white can capture the marked black stoned, this is ruled as: the white stones are dead, the marked black stone is not.

Why? Because black can get a living stone on the same intersection, which white cannot capture.

How?

Click Here To Show Diagram Code

[go]$$W
$$ X X X X | X X X X | X X X X | X X X X | X X X X |
$$ X O O X | X O O X | X . . X | X . . X | X . 4 X |
$$ O B . X | O . 1 X | O 2 . X | O X 3 X | O X . X |
$$ O O X X | O O X X | O O X X | O O X X | O O X X |[/go]

In the end, ended up on the same intersection as and could not be captured. Hence the original stone was alive.

The same is true for your example. Although white can capture the five black stones, black will ultimately capture white and can thus place living stones on (some of) the original five intersections. The same is not true for white. If white is captured here, any additional stones he triers to play inside will also be captured.

luigi wrote: So, in the determination-of-life-and-death phase, both players can ask for a chance to go first? That seems odd, and the both-dead result looks unnatural. I thought only the player who didn't pass last can go first...

Yes, the both dead result is unnatural, IMO. But the Japanese 1989 rules have lasted for quite a while. {shrug}

However, there are two different points of view about scoring the final position. One is, as you say, that who has the move is important. That was the view of, among others, Honinbo Shusai and Go Seigen. (But at that time there were no passes, so in Herman's example if White did not play after Black took the ko, the White stones were dead.) Another view is that the score does not depend upon who has the move. That is the view of the Japanese 1949 rules and the Japanese 1989 rules, as well as the Ing rules. So under the Japanese rules to resolve a question of life and death after play has stopped it is not that each player has the chance to go first, it is that each player must go first. That is why the play is hypothetical; no stone is placed on the board.

HermanHiddema wrote:Here's another, simpler, example of "both dead":

$$B Both players passed
$$ . O O O X X . . .
$$ . O X X O X . . .
$$ . O X . O X . . .
$$ -----------------

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[go]$$B Both players passed
$$ . O O O X X . . .
$$ . O X X O X . . .
$$ . O X . O X . . .
$$ -----------------[/go]

Really either player should have played here, but if they both pass, and you follow the rules, both groups are dead.

Note that the Japanese rules allow either player to request a resumption of the game, but they must let their opponent play first if they do, so neither player would want to, in a position like this.

It is true that this is an example of both dead. However, it may also be an example of rule 13: Both players lose because they have left a gainful play on the board. AFAIK, that rule has never been invoked in professional play. But I doubt if it has ever been invoked in amateur play, where it could well occur.

Bill Spight wrote: However, it may also be an example of rule 13: Both players lose because they have left a gainful play on the board. AFAIK, that rule has never been invoked in professional play. But I doubt if it has ever been invoked in amateur play, where it could well occur.

This clause always made me think of a parent disciplining their fighting children -- If you can't agree to play nice, then you both lose!