Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
RobertJasiek wrote:
Unlike Cassandra, I think that we cannot just dismiss these positions as unsettled and therefore immaterial as status precedents because the position might have the colour-reversed copy on the board so that a jigo is possible.
I am quite sure that the concrete result of a status assessment would be completely irrelevant, if such an "unsettled" position was mirrored elsewhere on the board.
Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
RobertJasiek wrote:
- The position above is the only counter-example to J2003/35a with its intention to model all positions (except the flawed official examples 16-18) according to common J pro understanding if implicitly it exists for a position.
J2003 is fine for examples 16 to 18, too, according to my understanding.
Your ko-pass rule lifts BOTH J89 ko-bans in the double-ko AT ONCE, what is the diciding feature.
What we do not know concerning examples 16 to 18 being potentially "flawed", because it cannot be concluded from the "known" English translation of J89: Does the Japanese understanding of lifting ko-bans during status confirmation demand that this is done in order? (You will realise that ALL the ko-ban-liftings, which are specifically stated with the examples, follow this principle.)
[go]$$Bm9 $$ +------------------------------ $$ | X X O 1 O 3 O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O a O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X 2 X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
White had passed for the lower ko with . The deciding moment comes now.
(Black's only chance to avoid the sequence below would be starting the double-ko loop by ko-passing for the upper ko with . Please note that it would be the ATTACKER, who utilised this means.) ((In J2003, would capture at "a", and capture White's stones at the top a bit later.))
[go]$$Bm9 $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X 4 X O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
This move is possible with nested ko shapes of the sandwiched group only.
[go]$$Bm9 pass $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X O 6 O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
RobertJasiek wrote:
If J2003 ko rules shall be redesigned, ko-pass should be avoided. I do not know if it is possible while maintaining most traditional beasts.
This is IMPOSSIBLE, Robert.
But may I suggest writing a ko-pass rule that is as SPECIFIC as possible, and which is designed ONLY for those cases that cannot be solved without?
I might be mistaken, but I am sure that the sole and only purpose for the J89 ko-ban was to enable the killing of TRIPLE-ko groups. See e.g. life-and-death example 8 "triple ko with an eye on one side".
However, the authors used a SINGLE-ko ban for this purpose, and -- as we now know -- this what not the very best idea, as they threw out the baby with the bathwater. Even your J2003 ko-pass rule, which of course solves the TRIPLE-ko issues, has unseen / unwanted side effects on SINGLE-ko (e.g. lightvectors finding) and DOUBLE-ko (e.g. Gérard's example).
Therefore, write a ko-pass rule for TRIPLE-ko, and undesirable side effects on SINGLE-ko and DOUBLE-ko are excluded from the outset. To give you an idea of what I have in mind (no idea to what extend this has to do with the "solution"):
"An uninterrupted sequence of TRIPLE-ko captures must not repeat its starting position."
I.e. latest move 6 of the TRIPLE-ko cycle is forbidden. At least, this would be sufficient to solve example 8.
To emphasise again: I do not have any idea about potential side effects
Posts: 1346 Liked others: 21 Was liked: 57
Rank: 1d
Cassandra wrote:
RobertJasiek wrote:
If J2003 ko rules shall be redesigned, ko-pass should be avoided. I do not know if it is possible while maintaining most traditional beasts.
This is IMPOSSIBLE, Robert.
Don't be so sure Cassandra. I think I have a solution without ko-pass. I continue my verifications
Cassandra wrote:
But may I suggest writing a ko-pass rule that is as SPECIFIC as possible, and which is designed ONLY for those cases that cannot be solved without?
I might be mistaken, but I am sure that the sole and only purpose for the J89 ko-ban was to enable the killing of TRIPLE-ko groups. See e.g. life-and-death example 8 "triple ko with an eye on one side".
However, the authors used a SINGLE-ko ban for this purpose, and -- as we now know -- this what not the very best idea, as they threw out the baby with the bathwater. Even your J2003 ko-pass rule, which of course solves the TRIPLE-ko issues, has unseen / unwanted side effects on SINGLE-ko (e.g. lightvectors finding) and DOUBLE-ko (e.g. Gérard's example).
Therefore, write a ko-pass rule for TRIPLE-ko, and undesirable side effects on SINGLE-ko and DOUBLE-ko are excluded from the outset. To give you an idea of what I have in mind (no idea to what extend this has to do with the "solution"):
"An uninterrupted sequence of TRIPLE-ko captures must not repeat its starting position."
I.e. latest move 6 of the TRIPLE-ko cycle is forbidden. At least, this would be sufficient to solve example 8.
To emphasise again: I do not have any idea about potential side effects
Your proposal does not solve the problem Cassandra because you act only on triple ko while the identified issues remaining on J2003 concerns only double ko.
Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
Gérard TAILLE wrote:
Your proposal does not solve the problem Cassandra because you act only on triple ko while the identified issues remaining on J2003 concerns only double ko.
[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]
is no longer an issue WITHOUT any special ko-pass rule during status confirmation.
The behaviour will be the same as during "play". -- White can capture Black's stones, if she moves first. -- White can capture Black's stones, even if Black moves first (i.e. Black cannot capture any of White's stones).
It remains the strategic decision, whether White wanted to invest another move, in order to get rid of the potential double-ko as a source of ko threats (assuming this position being part of a 19x19-board). But this is no longer a matter of the rules.
Posts: 1346 Liked others: 21 Was liked: 57
Rank: 1d
Cassandra wrote:
Gérard TAILLE wrote:
Your proposal does not solve the problem Cassandra because you act only on triple ko while the identified issues remaining on J2003 concerns only double ko.
With J2003 SINGLE-ko ban AND withOUT?
In J89 I do not like pass-for-a-ko and in J2003 I do not like ko-pass because they force the player to play a specific pass before recapturing a ko. I am looking for a solution which do not force such specific pass.
Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
Gérard TAILLE wrote:
Cassandra wrote:
Gérard TAILLE wrote:
Your proposal does not solve the problem Cassandra because you act only on triple ko while the identified issues remaining on J2003 concerns only double ko.
With J2003 SINGLE-ko ban AND withOUT?
In J89 I do not like pass-for-a-ko and in J2003 I do not like ko-pass because they force the player to play a specific pass before recapturing a ko. I am looking for a solution which do not force such specific pass.
Cassandra wrote:
"An uninterrupted sequence of TRIPLE-ko captures must not repeat its starting position."
does NOT enforce any pass. You many play whereever you want (but the specified board point at a specified moment). Whenever you like during the TRIPLE-ko sequence. Or pass, if you prefer it.
Please note that the basic ko rule for the application during play could be also written as
"An uninterrupted sequence of SINGLE-ko captures must not repeat its starting position."
Posts: 1346 Liked others: 21 Was liked: 57
Rank: 1d
Oops. By verifying if my solution works properly I analysed again positions like the very first positions I proposed in this thread and I found another position which could be an issue in J2003 (but it's not an issue for my solution ) Here it is :
[go]$$W $$ ----------------- $$ | B B . B . B O | $$ | B O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
What is the point? In normal play black marked stones are dead even if is black to play. My feeling in that case is that japonese professionnals will consider these stones are dead and can be added to the prisonners.
What is J2003 analysis? Can white capture these stones through the confirmation phase? Let's try:
[go]$$W $$ ----------------- $$ | B B 1 B . B O | $$ | B O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$W ko-pass connects the ko at $$ ----------------- $$ | 3 2 O B . B O | $$ | 4 O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
It is a loop => black stones are uncapturable => black stones are alive
Do you agree Robert?
Last edited by Gérard TAILLE on Thu Aug 19, 2021 2:15 pm, edited 1 time in total.
Posts: 1346 Liked others: 21 Was liked: 57
Rank: 1d
Cassandra wrote:
Gérard TAILLE wrote:
In J89 I do not like pass-for-a-ko and in J2003 I do not like ko-pass because they force the player to play a specific pass before recapturing a ko. I am looking for a solution which do not force such specific pass.
Cassandra wrote:
"An uninterrupted sequence of TRIPLE-ko captures must not repeat its starting position."
does NOT enforce any pass. You many play whereever you want (but the specified board point at a specified moment). Whenever you like during the TRIPLE-ko sequence. Or pass, if you prefer it.
Please note that the basic ko rule for the application during play could be also written as
"An uninterrupted sequence of SINGLE-ko captures must not repeat its starting position."
Again, NO pass is required. Simply play tenuki
Good news, if you look for solution without using ko-pass we are indeed looking for the same kind of solutions Sure we will prove it will be a success
Posts: 1326 Liked others: 14 Was liked: 153
Rank: German 1 Kyu
Gérard TAILLE wrote:
Good news, if you look for solution without using ko-pass we are indeed looking for the same kind of solutions Sure we will prove it will be a success
Probably I was not clear enough.
It will be necessary to have a specific ko BAN during status confirmation that differs from the ko BAN during "play". A specific board point must be taboo at a specific moment.
Forcing one player to sit around, while doing nothing for one move, during status confirmation will be superfluous.
Posts: 1346 Liked others: 21 Was liked: 57
Rank: 1d
Cassandra wrote:
Gérard TAILLE wrote:
Good news, if you look for solution without using ko-pass we are indeed looking for the same kind of solutions Sure we will prove it will be a success
Probably I was not clear enough.
It will be necessary to have a specific ko BAN during status confirmation that differs from the ko BAN during "play". A specific board point must be taboo at a specific moment.
Forcing one player to sit around, while doing nothing for one move, during status confirmation will be superfluous.
Yes Cassandra I agree with you. In my solution this specific ko ban I defined is very close to the ko ban used in normal play. In addition I am almost sure that to use this new ko ban in normal play will not change the way to play the game. I continue verifications.
[go]$$W $$ ----------------- $$ | B B . B . B O | $$ | B O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
What is the point? In normal play black marked stones are dead even if is black to play. My feeling in that case is that japonese professionnals will consider these stones are dead and can be added to the prisonners.
In principle, White cannot capture Black's stones at the top right during "play" (if Black insists on this fact). However, if she tries, there will develop a cycle, wherein White captures three Black stones, and White captures two Black stones. She will do so as long as necessary to win the game by her surplus prisoners.
During status confirmation, the position is seki.
White will have to capture Black's three stones at least once, I think.
[go]$$W $$ ----------------- $$ | . . W B . B O | $$ | . O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
If she did, she could capture Black's stones during status confirmation, while Black would be unable to capture White's.
[go]$$B $$ +------------------------------ $$ | . O O . O . O X O X X . . . . $$ | O X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X . X O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B $$ +------------------------------ $$ | 1 O O . O . O X O X X . . . . $$ | O X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X 2 X O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X O 3 O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B J89 "ko-ban lift in order": passes for $$ +------------------------------ $$ | X O O 5 O . O X O X X . . . . $$ | M X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B J89 "ko-ban lift in order": intermediate result $$ +------------------------------ $$ | X . . X O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
The TRIPLE-ko has vanished. It remains a double-ko at the right, for which the J89 ko-ban was NOT designed for!
Please note that the eye of Black's double-ko group is NOT SOLIDLY surrounded as in the J89 examples! (The shape of White's eye at the right does not matter.)
[go]$$B "completing a triple-ko cycle is prohibited" $$ +------------------------------ $$ | X O O . O . O X O X X . . . . $$ | 4 X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O 5 O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X ? X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | . O O . O . O X O X X . . . . $$ | O X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X . X O O X . . $$ | X X X X X O X . X O 7 O X . . $$ | O O O O O O X X ? X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B "completing a triple-ko cycle is prohibited": intermediate result $$ +------------------------------ $$ | . O O . O . O X . X X . . . . $$ | O X X O O O O X . . X X . . . $$ | X X X X X X O X X . . X X . . $$ | . . X , X O X X . X . . X . . $$ | X X X X X O X . X . X . X . . $$ | O O O O O O X X . X . . X . . $$ | . . . . . O O X X . . X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
=> White will interrupt the triple-ko cycle at latest.
[go]$$B J89 "ko-ban lift in order": continuation $$ +------------------------------ $$ | X . 6 X O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B J89 "ko-ban lift in order": passes for $$ +------------------------------ $$ | X 7 O . O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X M X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B J89 "ko-ban lift in order": $$ +------------------------------ $$ | X X O . O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O ? O O X . . $$ | X X X X X O X . B W . O X . . $$ | O O O O O O X B . B W O X . . $$ | . . . . . O O X B W O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
Please note that the shadowed point is still taboo for Black.
The formation at right has become kind of some "approach-move DOUBLE-ko" for Black, potentially (but seldom) favouring White. Seen from White's point of view, there is nothing more than a SIMPLE-ko now.
[go]$$Bm9 J89 "ko-ban lift in order": $$ +------------------------------ $$ | X X O 1 O 3 O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O ? O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X 2 . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 J89 "ko-ban lift in order": intermediate result #2 $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X B W . O O X . . $$ | X X X X X O B . B W . O X . . $$ | O O O O O O X B W . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
The SIMPLE-ko has changed place, and it's White to move.
[go]$$Bm9 J89 "ko-ban lift in order": passes for $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X 4 Z O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 J89 "ko-ban lift in order": final position $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X O 6 O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 J89 "ko-ban lift in order": conclusion $$ +------------------------------ $$ | . O O . O . O X W X X . . . . $$ | O X X O O O O X W W X X . . . $$ | X X X X X X O X X W W X X . . $$ | . . X , X O X X . X W W X . . $$ | X X X X X O X . X W . W X . . $$ | O O O O O O X X O . W W X . . $$ | . . . . . O O X X W W X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B "completing a triple-ko cycle is prihibited": continuation; passes $$ +------------------------------ $$ | X O O 5 O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B "completing a triple-ko cycle is prohibited": intermediate result #2 $$ +------------------------------ $$ | X . . X O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
The initial TRIPLE-ko has vanished. It remains a double-ko at the right, for which no special rule exists.
[go]$$B "completing a triple-ko cycle is prohibited" $$ +------------------------------ $$ | X . 6 X O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$B "completing a triple-ko cycle is prohibited" $$ +------------------------------ $$ | X 7 O . O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O 9 O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X 8 X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X O . O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X ? X O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
The shadowed point is taboo for White, due to the ordinary SIMPLE-ko ban.
[go]$$Bm9 "completing a triple-ko cycle is prohibited" $$ +------------------------------ $$ | X X O 3 O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X 4 X O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X O 5 O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X 6 X O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O 7 O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X ? X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 "completing a triple-ko cycle is prohibited" $$ +------------------------------ $$ | X X O . O . O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X . X O O X . . $$ | X X X X X O X . X O 9 O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 "completing a triple-ko cycle is prohibited": final position $$ +------------------------------ $$ | X X O . O . O X . X X . . . . $$ | . X X O O O O X . . X X . . . $$ | X X X X X X O X X . . X X . . $$ | . . X , X O X X . X . . X . . $$ | X X X X X O X . X . X . X . . $$ | O O O O O O X X . X . . X . . $$ | . . . . . O O X X . . X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
Same consequnce of the TRIPLE-ko ban as above for the initial TRIPLE-ko.
[go]$$Bm9 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X . X O 7 O X O X X . . . . $$ | . X X O O O O X O O X X . . . $$ | X X X X X X O X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X . X O . O X . . $$ | O O O O O O X X . X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O . O O X . . $$ | X X X X X O X 9 X O . O X . . $$ | O O O O O O X X 8 X O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm19 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X O 1 O O X . . $$ | X X X X X O X X X O . O X . . $$ | O O O O O O X X O . O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm19 "completing a triple-ko cycle is prohibited": passes $$ +------------------------------ $$ | X X . X . X . X O X X . . . . $$ | . X X . . . . X O O X X . . . $$ | X X X X X X . X X O O X X . . $$ | . . X , X O X X 3 X O O X . . $$ | X X X X X O X X X O 7 O X . . $$ | O O O O O O X X O 5 O O X . . $$ | . . . . . O O X X O O X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm19 "completing a triple-ko cycle is prohibited": final position $$ +------------------------------ $$ | X X . X . X . X . X X . . . . $$ | . X X . . . . X . . X X . . . $$ | X X X X X X . X X . . X X . . $$ | . . X , X O X X X X . . X . . $$ | X X X X X O X X X . X . X . . $$ | O O O O O O X X . X . . X . . $$ | . . . . . O O X X . . X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$Bm9 J89 "ko-ban lift in order": conclusion $$ +------------------------------ $$ | . O O . O . O X P X X . . . . $$ | O X X O O O O X P P X X . . . $$ | X X X X X X O X X P P X X . . $$ | . . X , X O X X . X P P X . . $$ | X X X X X O X . X P . P X . . $$ | O O O O O O X X P . P P X . . $$ | . . . . . O O X X P P X X . . $$ | . . . . . . O O O X X X . . . $$ | . . . . . . . . . . . . . . . $$ | . . . , . . . . . , . . . . .[/go]
[go]$$W $$ ----------------- $$ | B B . B . B O | $$ | B O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
What is the point? In normal play black marked stones are dead even if is black to play. My feeling in that case is that japonese professionnals will consider these stones are dead and can be added to the prisonners.
In principle, White cannot capture Black's stones at the top right during "play" (if Black insists on this fact). However, if she tries, there will develop a cycle, wherein White captures three Black stones, and White captures two Black stones. She will do so as long as necessary to win the game by her surplus prisoners.
During status confirmation, the position is seki.
White will have to capture Black's three stones at least once, I think.
[go]$$W $$ ----------------- $$ | . . W B . B O | $$ | . O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
If she did, she could capture Black's stones during status confirmation, while Black would be unable to capture White's.
Yes Cassandra, that is the point, in J2003, white has to add a move to avoid the seki according to the confirmation phase. But what is the expected result?
[go]$$W $$ ----------------- $$ | B B . B . B O | $$ | B O B B B B O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | B O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
Assume you are facing a japonese professionnal which do not know what a confirmation phase is. You are the black player and you claim for a seki and the win of the game (because white fails to add a move). I imagine easily the answer : no, be serious, (in normal play) black is dead even if she plays first => black is dead and the marked black stones are simply prisonners => you are losing the game. I do not have to add another move and I advise you to take another rule So Cassandra, what is the expected result for you (in order to know is the result given by J2003 sounds correct or not)?
[go]$$W $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
#################### ####################
Stones that shall be taken off the board as prisoners after "play" has ended demand an opponent's "two-eyed alive" group that surrounds them completely. Please remember that a "two-eyed alive" group requires (at least) TWO completely surrounded board points that are forbidden by the rules for the opponent to occupy -- aka "eye points" -- (or can be transformed into such, even if the opponent plays first).
[go]$$W $$ ----------------- $$ | X X . X . X Q | $$ | X Q X X X X Q | $$ | Q Q Q Q Q Q Q | $$ | . Q X X X X X | $$ | X Q X . . X . | $$ | . Q X . . X X | $$ | Q Q X . . X . | $$ -----------------[/go]
Let's try to find out whether White's marked group can achieve that required status.
[go]$$B $$ ----------------- $$ | X X 2 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | 1 O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | . 3 O X . X O | $$ | . O X X X X O | $$ | O O O O O O O | $$ | X O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | 4 X . X . X O | $$ | 5 O X X X X O | $$ | O O O O O O O | $$ | X O X X X X X | $$ | X O X . . X . | $$ | 6 O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | 7 X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | . O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X 8 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | . O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | . 9 O X . X O | $$ | . O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | . O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$Bm9 $$ ----------------- $$ | 2 X . X . X O | $$ | 3 O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | . O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$Bm9 passes $$ ----------------- $$ | 5 X 6 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | C O X X X X X | $$ | C O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
Ad infinitum ...
ONE two-point eye (corresponds to ONE eye point) only => The answer is "NO".
[go]$$Bm7 $$ ----------------- $$ | . X . X . X O | $$ | 4 O X X X X O | $$ | O O O O O O O | $$ | 5 O X X X X X | $$ | 6 O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$Bm7 passes $$ ----------------- $$ | . X . X . X O | $$ | O O X X X X O | $$ | O O O O O O O | $$ | C O X X X X X | $$ | O O X . . X . | $$ | O O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$W $$ ----------------- $$ | X X . X . X Q | $$ | X Q X X X X Q | $$ | Q Q Q Q Q Q Q | $$ | . Q X X X X X | $$ | . Q X . . X . | $$ | . Q X . . X X | $$ | Q Q X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X 2 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | . 3 O X . X O | $$ | . O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | 4 X . X . X O | $$ | 5 O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B passes $$ ----------------- $$ | 7 X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | C O X X X X X | $$ | B O X . . X . | $$ | C O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
ONE three-point eye (corresponds to ONE eye-point) only => The answer would be "NO" again.
[go]$$W may be at a, too $$ ----------------- $$ | X X 1 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | a O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
Therefore, White should have added a move during "play".
Contrary to that, in your position in question ...
[go]$$B $$ ----------------- $$ | X X 2 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
... Black mistakenly triggered that White move, providing White with an additional prisoner unnecessarily.
[go]$$W $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
OK Cassandra you consider white has to add a move. We cannot agree on all points can we. Why am I considering white do not need to add a move? In this kind of position where no one-sided dame exist then I trust the result given by japonese Bill Spight rule. Here, in the encore, because black cannot afford to defend the position with a loop in which white gains more prisoners, black will be killed. You do not trust Japonese Bill Spight rule? I understand you want to build a two-eyes group but is it acceptable to defend a position using a loop in which your opponent gets more prisonners? You say yes but it does not sound acceptable for me. That is the point where we do not agree.
[go]$$W $$ ----------------- $$ | X X . X . X Q | $$ | X Q X X X X Q | $$ | Q Q Q Q Q Q Q | $$ | . Q X X X X X | $$ | . Q X . . X . | $$ | . Q X . . X X | $$ | Q Q X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X 2 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | . 3 O X . X O | $$ | . O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | 4 X . X . X O | $$ | 5 O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B passes $$ ----------------- $$ | 7 X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | X O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | C O X X X X X | $$ | B O X . . X . | $$ | C O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
ONE three-point eye (corresponds to ONE eye-point) only => The answer would be "NO" again.
[go]$$W may be at a, too $$ ----------------- $$ | X X 1 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | a O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
Therefore, White should have added a move during "play".
Contrary to that, in your position in question ...
[go]$$B $$ ----------------- $$ | X X 2 X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
... Black mistakenly triggered that White move, providing White with an additional prisoner unnecessarily.
[go]$$B $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
I you begin the confirmation phase by this black move that means that you try to kill white and we agree it is not possible.
If now white wants to prove she can kill black stones she will simply begin by:
[go]$$W $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
[go]$$B $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
I you begin the confirmation phase by this black move that means that you try to kill white and we agree it is not possible.
If now white wants to prove she can kill black stones she will simply begin by:
[go]$$W $$ ----------------- $$ | X X . X . X O | $$ | X O X X X X O | $$ | O O O O O O O | $$ | . O X X X X X | $$ | 1 O X . . X . | $$ | . O X . . X X | $$ | O O X . . X . | $$ -----------------[/go]
Where is your point with this position?
It does NOT matter whether White can kill Black's stones or not during status confirmation.
The deciding question is whether you can turn White's group into a "two-eyed alive" one, even if Black moves first. Only if you can answer this question with "yes", you have achieved "INDEPENDENT life" for White's group (probably you like this wording more).
There are TWO conditions for Black stones (which remained on the board) that shall become White's prisoners after the end of the game, i.e. without really capturing these by actual play: These stones did NOT achieve the property "two-eyed alive" during status confirmation. These stones must be fully enclosed by (nothing else than) a White group that has achieved the property "two-eyed alive" during status confirmation.
In your example, condition is fulfilled, but condition is not. Therefore, the entire position is a seki.
Please note that you will not find any "dead" in my writing above. Just because this term would be only a descriptive one (and no specifying one) for Black stones that fulfill BOTH conditions and above. There is NO death DURING status confirmation, which would make its way back onto the board position at the end of "play" (i.e. at the start of the status confirmation). Whether stones are "dead" or not is decided after the status confirmation of all (relevant) groups has been finished, and derived from the combination of all these results, as I tried to explain above.
Please to not mix "two-eyed alive" with J89's or J2003's "uncapturable" / "capturable-1".
Users browsing this forum: No registered users and 1 guest
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum