How can you force black to play if black considers it is seki? It will be a suicide no?

I completly agree with you.

In any case it seems easy to modify the earlier example to allow B ko abuse (like the other known anomalies). In a game phase with this huge difference in ko rules, no surprise if the outcome will not always match real go. Doubtful approach.

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | O X . X . O . |
$$ | 1 O X X X O O |
$$ | O . O X O 2 O |
$$ | O O O X X O . |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]

All White stones are alive.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

BUT (a very big but) why do you imagine white would pass for 4? White 4 would capture in the top right ko putting the black stones a the top in atari and they cannot connect (connect and die)

This is the major flaw of J89 in my mind: Neither player is required to do anything, they can disagree about every group and refuse to play more moves by passing when the game resumes and never agree to end the game. There is no recourse to an arbitrator or anything like that, and the process of "confirmation" is also not defined thought there are plenty of examples of how to apply the rules during confirmation.

Also, it wouldn't be seki. The black stones are just dead, but the white stones are plausibly dead in mutual-death. The life and death of the white and black stones are not connected in the confirmation like it is in seki. The white stones are dead because of a ko that black can neither connect nor capture, except in confirmation. There is also a question if the white stones are really dead during confirmation because white can live some of them and play a single stone in place of the captured ones.

It is really not the "good sense" required in the preamble and this kind of monster is obviously not intended in the J89 rules. It also seem that the dead black stones remain on the board and are not added to the territory as prisoners, what kind of dead group is that? I think mutual-death is a situation that we need to apply the "good sense" to. I view this the same way that in physics and analysis we can have removable singularities and continues extensions, and cover up the monsters. In this case it is only white that is dead by mutual-death, it is a phantom death because it can not happen during regular play and if we considered it dead this results in dead stones not being removed at the end of the game which we should disallow by axiom. It seems clear to me that it should be considered alive despite everything.

I am very sure that the Nihon Kiin 1989 Rules were never ever written for a Western audience.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Your right Cassandra. Your is better but you cannot say white stones are alive. As previoulsly only a part of white stones are alive.

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | O X . X a O . |
$$ | 1 O X X X O O |
$$ | O 3 O X O 2 O |
$$ | O O O X X O . |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]

The white marked stones are dead. BTW because point a is a dame all white stones are still in seki. I hoped to find an example without dame but it is not the case with this example.

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | . X . X 4 O . |
$$ | X 5 X X X O O |
$$ | O X O X O 2 O |
$$ | O O O X X O . |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]

Click Here To Show Diagram Code

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

As a conclusion the marked stones are dead. The point "a" is a dame and all white stones are in seki with the marked black stones.

It is interesting to not that if, before passing, black plays

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | O X . X . O . |
$$ | 1 O X X X O O |
$$ | O 2 O X O . O |
$$ | O O O X X O . |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]

then now the black stones are dead and the white stones are alive.

Simply because we are in the confirmation phase and white has not passed for the two kos taken by black.

Maybe I have found a position in which all black stones at the top and all white stones are dead in the confirmation phase:

Click Here To Show Diagram Code

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

Here again, if black, in normal play, plays the exchange:

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | O X . X . O . |
$$ | 1 O X X X O O |
$$ | O 2 O O X X O |
$$ | O O O . O X O |
$$ | X X O O X X O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

then now the black stones at the top are dead while white stones are alive.

@Mike Novack - It sounds you might just not be aware of this: under J89 rules, the hypothetical play to confirm life&death uses an alternative ko rule in which you can only recapture a ko after you make a pass for it. Ko threats or intervening moves on the rest of the board are not supposed to matter, the only thing that lets you retake is a pass. The motivation behind the Japanese rules drafters including such a weird ko rule is because they wanted things like bent-four-in-the-corner to be dead in hypothetical play regardless of if there are unremovable ko threats elsewhere on the board. No longer do other ko threats matter with such a rule, so you get the desired result. But as you can see in the discussion in this thread, such a rule might lead to weird consequences the drafters did not foresee.

is a new stone that has come into being, and that cannot be captured by the opponent.

Therefore, both marked White stones in the upper left are alive!

Apparently, you are not aware that it is NOT mandatory to have the "new stone that has come into being" at any spot on the board where White stones have been taken off before. You may want to study life-and-death example 4.
And also apparently, you have missed that a status confirmation that starts with a BLACK move is ONLY about the status of a WHITE group. The seemingly result of the sequence that has been used during status confirmation "on the board" on other groups but the one under current inspection is irrelevant, as its starting position (= the position after the game stopped) will be recreated again after each status confirmation.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Yes, the position in the upper right is seki.

However, ...

Click Here To Show Diagram Code

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

Do you really assume to see the position in the upper left corner at the start of a status confirmation?

You should try to find examples, which do NOT include "unfinished" positions.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

The major J89 flaw is to presume, but completely ignore, strategy (the decision-making among alternating sequences) in hypothetical play in the rules text. The second-most important major J89 flaw is to presume alternating sequences in hypothetical play but hide them behind grammar of modal verbs in "cannot [be captured...] if [...] could not [capture]".



Presumably this was the intention but almost all ko shapes including bent-four-in-the-corner do not require a hypothetical ko rule - the basic ko rule would be sufficient. The known ko shapes with actually different behaviour are:

- position with double ko death and elsewhere a teire ko

- triple ko shape with one external ko

The J89 rules writers were only aware of the impact on the latter, which is less frequent than the former ko shape.

Dear Robert,

As I have already mentioned, the Nihon Kiin 1989 Rules were never ever written for a Western audience that you are a member of.

-- You do not understand the language.
-- You do not have any feeling for the culture.
-- But you are using your very special Western value system to condemn something that was never intended to be applied by you.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

By this logic almost anything is alive if defender plays a live stone somewhere else in his territory. The new stone must be a direct result of the capture, it must not be possible to play it otherwise.

I don't think "confirmation" is supposed to include competition in J89, it is not "play" it is one player demonstrating how a disputed group is dead. The players are somehow supposed to reach an agreement when they disagree.

I don't think I can agree that "strategy" during confirmation is the major flaw, the only strategy that I find is that players may assign different value to different results. I suppose it is related, player A and player B may agree to 1-0, player A and player C may agree to no-result and player B and player C just sit there trying to stare each other down forever

Please refer to life-and-death example 4.

Then you will probably understand.
There, the new stone that makes White's group alive is played at a board point, where no White stone has been captured before.

As a matter of course, it would have been advisable to describe the area in which such new stone could be played in the text of the rules. But apparently, the authors of the rules did not have such artifically created positions in mind, which sole purpose in life is to track down alleged formulation deficiencies.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

The location of the new stone (and whether a stone was captured from there) doesn't matter, only the logical connection: the new stone was not possible before, but the capture made it possible. In example 4 W cannot play live stones by his own will.

kvasir, during ordinary play, players may make mistakes when using strategy. In analysis play, hypothetical strategy must be applied without mistakes; there is no competition.

Cassandra, originally J89 were written by professional players for themselves and therefore not for Japanese amateurs, foreign amateurs or me. Japanese professional players have spread, or contributed to spreading, go in many countries of the world using Japanese style rules. In particular, they did so before I wrote down verbal Japanese rules. Therefore, Japanese style rules have been spread to various countries regardless of their originally limited intended scope of application. In particular, J89 were used in most EGF tournaments from, IIRC, 1997 to 2007. In particular, I did play in such tournaments.

Simply speaking, I do not understand Japanese. In old times, people did not understand Hebrew, Greek or Latin and nevertheless applied the Bible. That is why translations exist: enable understanding and interpretation of contents despite not understanding the original language. Do you suggest that nobody except those understanding Hebrew may ever apply the contents of the Bible and nobody except those understanding Japanese may ever interpret the rules?! Your contribution to translation is welcome but you do not possess the exclusive right to interpretation.

Do not make wrong assumptions about my understanding of Japanese culture! In particular, it is much richer than you imply. E.g., it contains both a preference for exactness and, by others, a preference for ambiguity.

You suggest that my Western value system would be very special. This system includes exactness, truth and logic. Values belonging to the basics of maths, science etc. and widely applied at school, university and jurisdiction. Contrary to being very special. Even applied by Japanese professional players in play and teaching whenever their knowledge and ability allows.

Do I condemn J89? Yes. More importantly, I criticise them and suggest corrections. Do you praise them and suggest to keep them exactly as they are?

I confess easily that I have difficulties to inderstand the following wording of the rule (and I guess I am not alone with this difficulty):
"if capturing them would enable a new stone to be played that the opponent could not capture"
but, with this discussion, I think I make progress though slowly.

You say :w2: is a new stone that has come into being, and that cannot be captured by the opponent. Surely cannot be capture but in any case , through confirmation play (and also through normal play!), black cannot prevent white to occupy definitly this point. As a consequence, it seems to me it is not the capture itself of the marked stones which allows white to play . How can you conclude white marked stones are alive?