Life In 19x19

Analysis so far misses the following:

- One sequence per status might not be enough.
- Play before successive passes can result in different scoring positions, of which each must be analysed by hypothetical play to then evaluate strategy before successive passes.
- Different Japanese rulesets require different applications.

3-4 hours analysis time is the lower bound. Spending a few minutes on random thoughts does not do it.

Gérard TAILLE wrote:black : OK in that case we enter the confirmation phase. Because you refuse to add a move that means you consider black stones are dead even if it is black to play right?
White : yes
Black : in that case I start the confirmation phase and you will try to kill me, correct?
White : yes, let's go

As I already stated above, the text in red is mistaken, at least if you want to apply Nihon Kiin 1989 Rules.

The STATUS CONFIRMATION of each and every single group of stones on the board starts with the FINAL POSITION of "PLAY".
It does NOT matter at all which side put the last stone onto the board.
There is NO conjunction between PLAY and STATUS CONFIRMATION.

"... cannot be captured by the opponent, ..." implies that White starts the status confirmation for a Black group.
If Black ever wanted to add a stone before, he would have had to do it during "PLAY".

+ + + + + + + + + + +

For comparison:
If STATUS CONFIRMATION is entered with the central point of a genuine Nakade shape unoccupied (both players had a blind spot here), the status of the relevant group is "dead", NOT "alive".

I also think J89 analysis starts with attacker.

Gérard TAILLE wrote:I will try to analyse this simpler position in an other post, and please try to take into account only my modified position.

Click Here To Show Diagram Code

[go]$$B Final position of PLAY
$$ ---------------------
$$ | . X . X O O . X X |
$$ | X O X X X X X X X |
$$ | O O O O O O O O O |
$$ | O O X X X O O O X |
$$ | . O X O O O O O X |
$$ | X O X X X X X X X |
$$ | . O X . . . . X . |
$$ | O O X . . . . X X |
$$ | O O X . . . . X . |
$$ ---------------------[/go]

+ + + + + + + + + +

Click Here To Show Diagram Code

[go]$$W status confirmation for Black's group
$$ ---------------------
$$ | 1 X 3 X O O 4 X X |
$$ | X O X X X X X X X |
$$ | O O O O O O O O O |
$$ | O O X X X O O O X |
$$ | 2 O X O O O O O X |
$$ | X O X X X X X X X |
$$ | . O X . . . . X . |
$$ | O O X . . . . X X |
$$ | O O X . . . . X . |
$$ ---------------------[/go]

Click Here To Show Diagram Code

[go]$$W status confirmation for Black's group
$$ ---------------------
$$ | O . O X 5 7 X X X |
$$ | . O X X X X X X X |
$$ | O O O O O O O O O |
$$ | O O X X X O O O X |
$$ | X O X O O O O O X |
$$ | X O X X X X X X X |
$$ | . O X . . . . X . |
$$ | O O X . . . . X X |
$$ | O O X . . . . X . |
$$ ---------------------[/go]

PASS for lifting the ko ban
+ + + + + + + + + +

Click Here To Show Diagram Code

[go]$$B status confirmation for White's group
$$ ---------------------
$$ | 2 X 4 X O O 5 X X |
$$ | X O X X X X X X X |
$$ | O O O O O O O O O |
$$ | O O X X X O O O X |
$$ | 1 O X O O O O O X |
$$ | X O X X X X X X X |
$$ | . O X . . . . X . |
$$ | O O X . . . . X X |
$$ | O O X . . . . X . |
$$ ---------------------[/go]

Click Here To Show Diagram Code

[go]$$B status confirmation for White's group
$$ ---------------------
$$ | O 6 O X . . X X X |
$$ | . O X X X X X X X |
$$ | O O O O O O O O O |
$$ | O O X X X O O O X |
$$ | X O X O O O O O X |
$$ | X O X X X X X X X |
$$ | . O X . . . . X . |
$$ | O O X . . . . X X |
$$ | O O X . . . . X . |
$$ ---------------------[/go]

+ + + + + + + + + +

Click Here To Show Diagram Code

[go]$$B Result of STATUS CONFIRMATION
$$ ---------------------
$$ | . Z . Z W W . Z Z |
$$ | Z W Z Z Z Z Z Z Z |
$$ | W W W W W W W W W |
$$ | W W X X X W W W X |
$$ | . W X W W W W W X |
$$ | Z W X X X X X X X |
$$ | . W X . . . . X . |
$$ | W W X . . . . X X |
$$ | W W X . . . . X . |
$$ ---------------------[/go]

All of Black's stones in question are dead.

_________________________________
EDITED

In confirmation cannot retake ko without passing for it.

jann wrote:In confirmation cannot retake ko without passing for it.

Ups

This results in the death of Black's group at the top (edited my posting accordingly in the meantime).

Cassandra wrote:

Gérard TAILLE wrote:black : OK in that case we enter the confirmation phase. Because you refuse to add a move that means you consider black stones are dead even if it is black to play right?
White : yes
Black : in that case I start the confirmation phase and you will try to kill me, correct?
White : yes, let's go

As I already stated above, the text in red is mistaken, at least if you want to apply Nihon Kiin 1989 Rules.

The STATUS CONFIRMATION of each and every single group of stones on the board starts with the FINAL POSITION of "PLAY".
It does NOT matter at all which side put the last stone onto the board.
There is NO conjunction between PLAY and STATUS CONFIRMATION.

"... cannot be captured by the opponent, ..." implies that White starts the status confirmation for a Black group.
If Black ever wanted to add a stone before, he would have had to do it during "PLAY".

+ + + + + + + + + + +

For comparison:
If STATUS CONFIRMATION is entered with the central point of a genuine Nakade shape unoccupied (both players had a blind spot here), the status of the relevant group is "dead", NOT "alive".

I am happy with your answer Cassandra because it is really how I would like to read the rule. But the point is that by reading carefully this rule I do not find clearly who will start the confirmation phase:

Article 7. Life and death
1. Stones are said to be "alive" if they cannot be captured by the opponent, or if capturing them would enable a new stone to be played that the opponent could not capture. Stones which are not alive are said to be "dead."

I agree that "if they cannot be captured by the opponent" may imply that the attaker will start the confirmation phase but it is not stated clearly. In addition the rule defines "alive" stones and then the rule define "dead" stones being stones which are not "alive". That may also imply that the defender may start the confirmation phase to prove her stones are alive (they cannot be capture by the opponent).

Let's consider a provocative example

Click Here To Show Diagram Code

[go]$$B Confirmation phase
$$ -------------
$$ | . a . X O |
$$ | X X X X O |
$$ | O O O O O |
$$ | . . . . . |
$$ | . . . . . |
$$ -------------[/go]

Assume a game ends in this position.

Black : you fail to play at "a". By starting the confirmation phase, I can prove my black stones cannot be captured => black stones are alive
White : you fail to play at "a". By starting the confirmation phase I can prove I can capture black stones => black stones are dead

Who is right according to the strict application of the rule? I prefer your view Cassandra (ie. white is right) but the rule does not say explicitly who (the defender or the attacker) will start the confirmation. A lot of examples are done in the rule but for each of them the defender has never a good move at her disposal. That means that the examples given does not really helps.
My example is only here to show that the rule does not explicitly explain how the confirmation phase should start.

Dear Gérard,

I would like to assume that this apparent ambiguity is due to the "known" English translation(s) of the Nihon Kiin 1989 Rules, which do not include each and every implicit aspect (or have taken such for self-evident). But it does NOT exist in Japanese!

The relevant fraction of the original text is
"相手方_の_着手_により_取られない_石, ..."

An English translation of the (by me) seperated Japanese "words" (word by word) might be
"Opponent_'s_move_by_not capturable_stone, ..."
and should be read from the back, resulting in
"A stone that cannot be captured by a move of the opponent, ..."

In Japanese, there is no explicit distinction between "stone" and "group".
An analogous transfer for "group" would be (according to my rudimentary understanding of Japanese)
"A group that cannot be captured by the opponent, even if he moves first, ..."

So both players passed while being aware that the position was unsettled and then called a referee to settle the matter?
I suppose this might be a case where a referee could declare the game a loss for both players.

gennan wrote:So both players passed while being aware that the position was unsettled and then called a referee to settle the matter?
I suppose this might be a case where a referee could declare the game a loss for both players.

This would be the case, only if both players refused to declare that the game has ended.
But this in not the case in Gérard's example.

Cassandra wrote:Dear Gérard,

I would like to assume that this apparent ambiguity is due to the "known" English translation(s) of the Nihon Kiin 1989 Rules, which do not include each and every implicit aspect (or have taken such for self-evident). But it does NOT exist in Japanese!

The relevant fraction of the original text is
"相手方_の_着手_により_取られない_石, ..."

An English translation of the (by me) seperated Japanese "words" (word by word) might be
"Opponent_'s_move_by_not capturable_stone, ..."
and should be read from the back, resulting in
"A stone that cannot be captured by a move of the opponent, ..."

In Japanese, there is no explicit distinction between "stone" and "group".
An analogous transfer for "group" would be (according to my rudimentary understanding of Japanese)
"A group that cannot be captured by the opponent, even if he moves first, ..."

Thank you Cassandra for this interesting translation.
BTW, do you know if a better translation has been made since this (quite old ) version pointed by the link http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html ?

Cassandra wrote:

gennan wrote:So both players passed while being aware that the position was unsettled and then called a referee to settle the matter?
I suppose this might be a case where a referee could declare the game a loss for both players.

This would be the case, only if both players refused to declare that the game has ended.
But this in not the case in Gérard's example.

I don't understand. Both players passed, which implies they both declare the game ended. How can players ever pass and at the same time deny that the game has ended? That makes no sense (and it violates article 9).

To me, Gerard's example looks like a case where the players colluded to troll the referee, so declaring a loss for both seems appropriate.

gennan wrote:

Cassandra wrote:

gennan wrote:So both players passed while being aware that the position was unsettled and then called a referee to settle the matter?
I suppose this might be a case where a referee could declare the game a loss for both players.

This would be the case, only if both players refused to declare that the game has ended.
But this in not the case in Gérard's example.

I don't understand. Both players passed, which implies they both declare the game ended. How can players ever pass and at the same time deny that the game has ended? That makes no sense (and it violates article 9).

To me, Gerard's example looks like a case where the players colluded to troll the referee, so declaring a loss for both seems appropriate.

Oops It looks my wording was incorrect. I wrote:

Gérard TAILLE wrote: Let's consider a provocative example

$$B Confirmation phase
$$ -------------
$$ | . a . X O |
$$ | X X X X O |
$$ | O O O O O |
$$ | . . . . . |
$$ | . . . . . |
$$ -------------

Click Here To Show Diagram Code

[go]$$B Confirmation phase
$$ -------------
$$ | . a . X O |
$$ | X X X X O |
$$ | O O O O O |
$$ | . . . . . |
$$ | . . . . . |
$$ -------------[/go]

Assume a game ends in this position.

Black : you fail to play at "a". By starting the confirmation phase, I can prove my black stones cannot be captured => black stones are alive
White : you fail to play at "a". By starting the confirmation phase I can prove I can capture black stones => black stones are dead

Obviously there is a contradiction saying "game ends in this position" and at the same time saying we "start the confirmation phase".
Probably I should have written "game stops in this position". Surely I am not an expert in wording and so I am not able to help you a lot.

Gérard TAILLE wrote:BTW, do you know if a better translation has been made since this (quite old ) version pointed by the link http://www.cs.cmu.edu/~wjh/go/rules/Japanese.html ?

No, I don't.

But I am afraid that there is none.

gennan wrote: I don't understand. Both players passed, which implies they both declare the game ended. How can players ever pass and at the same time deny that the game has ended? That makes no sense (and it violates article 9).

To me, Gerard's example looks like a case where the players colluded to troll the referee, so declaring a loss for both seems appropriate.

Article 9. End of the game
1. When a player passes his move and his opponent passes in succession, the game stops.
2. After stopping, the game ends through confirmation and agreement by the two players about the life and death of stones and territory. This is called "the end of the game."
3. If a player requests resumption of a stopped game, his opponent must oblige and has the right to play first.