RobertJasiek wrote:
Cassandra wrote:
- Click Here To Show Diagram Code
[go]$$B pass
$$ +---------------------------------------+
$$ | X X Q . Q . O X Q ? O . O X . . . . . |
$$ | . X X Q O O O X Y Q O O O X . . . . . |
$$ | X X . X X X O X C Y O X X X . . . . . |
$$ | . . . , X O X X Y O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]
can
ONLY pass!
There is still an
UNLIFTED ko-ban on the board, so White is hindered to capture with
!
Please explain meticulously why, at this moment, this is so according to your current reading of the rules.
Dear Robert,
Let me first go a little further ...
In the thread
GT territory rules:: Honte's loops and cycles -- completely unintentional during the analysis of loops and cycles -- has been discovered, and thereafter explained in great detail, that a (GENUINE) double-ko does not have any effect during status confirmation.
It does not make any difference,
whether it is kept in its original formation, as utilising the double-ko cycle (ko-capture, ko-capture, pass / tenuki, ko-capture, ko-capture, pass / tenuki) has the SAME effect as playing elsewhere (=> pass / tenuki, pass / tenuki)
whether -- it being a (at least temporary) seki -- it is transformed into an equivalent (at least temporary) seki that does not contain any ko-shape. In this case, the four meaningless ko-captures in
are excluded from the very beginning.
(not explicity mentioned there) when being part of a sandwich-formation (i.e. at least three groups are involved in a joint status analysis), whether the double-ko is replaced by an independently alive group of the colour that is neighboured to the rest of the sandwich. That will save the possible "collapse of the seki".
I have summarized this strikingly with "There is no double-ko during the status confirmation" in the thread linked to above.
Your J2003's "pass-for-all-ko" ultimately led to keeping
alive.
+++++++++++++++++++++++++Let us analyze the behavior resulting from my understanding of the Japanese original using the example of a standard (i.e. isolated) double-ko:
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y . Y O X . .
$$ | X X Y O O X . .
$$ | Q X O . O X . .
$$ | . Q O O O X . .
$$ | Q O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y . Y O X . .
$$ | X X Y O O X . .
$$ | Q X O . O X . .
$$ | 1 Q O O O X . .
$$ | Q O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
captures into the ko-shape at left.
(The position is symmetrical, so the result would be the same (just with reversed colours), if we let White start the status confirmation by capturing into the ko-shape at the top.)
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y . Y O X . .
$$ | Y X Y O O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
During status confirmation, capturing into a ko-shape turns this ko-shape into a "hot" one (in the sense of "explosive").
IMMEDIATE re-capture into that ko is forbidden, while the player who just created this "hot" ko would still be allowed to fill it
(which might not always be the best idea, by the way).
(
I utilised here (instead of the shadow) to make this "hotness" more explicite in the diagram.)
is forbidden, while
is a valid move.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y 2 Y O X . .
$$ | Y X Y O O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
Black's previous move was an atari, so
has to capture into the ko at the top.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . X Q M Q X . .
$$ | Y X Y Q O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
This turns the ko-shape at the top into a "hot" one, too.
For that ko at the top,
is forbidden, while
is a valid move.
After White's ko-capture at the top, there are TWO of these "hot" ko on the board.
- Click Here To Show Diagram Code
[go]$$B pass-for-ko (top)
$$ +----------------
$$ | . X Q M Q X . .
$$ | Y X X Q O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
Let us assume that Black wanted to re-capture into that ko at the top at all costs.
In this case, he must play a "pass-for-ko" for that ko.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . X Q T Q X . .
$$ | Y X X Q O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
By Black's previous move, that ko at the top has lost its "hot" status.
However, the ko-shape at the top has NOT returned into it "ordinary" status! Whether Black is allowed or not to re-capture into that ko at the top DEPENDS (thus the
to make that clearer)!!!
On the board, there is still ONE of these "hot" ko.
- Click Here To Show Diagram Code
[go]$$B pass
$$ +----------------
$$ | . X Q T Q X . .
$$ | Y X X Q O X . .
$$ | M Y O S O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
at the top would be IMMEDIATELY suicidal, so White plays a "pass" (
to the right would be suicidal as well, just a bit later).
- Click Here To Show Diagram Code
[go]$$B would be illegal!!!
$$ +----------------
$$ | . X Q 5 Q X . .
$$ | Y X X Q O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
At the left edge, there is still ONE of these "hot" ko on the board, so re-capturing into that ko at the top is forbidden during status confirmation!!!
-------------------------
Variation:
- Click Here To Show Diagram Code
[go]$$B pass-for-ko (left)
$$ +----------------
$$ | . X Q T Q X . .
$$ | Y X X Q O X . .
$$ | M Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
White plays a "pass-for-ko" for that still "hot" ko at the left.
This is what has been choosen for the respective J89 sequence.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . X Q T Q X . .
$$ | Y X X Q O X . .
$$ | T Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
ALL of these former "hot" ko have disappeared from the board.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . X Q . Q X . .
$$ | Y X X Q O X . .
$$ | . Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
ALL of these former "hot" ko-shapes have become "ordinary" again.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . X Q 5 Q X . .
$$ | Y X X Q O X . .
$$ | . Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
Capturing into the ko-shape at the top is a valid move, as there are NEITHER "hot" ko on the board NOR "depends" ones.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y M Y O X . .
$$ | Y X Y O O X . .
$$ | 6 Y O . O X . .
$$ | Y O O O O X . .
$$ | O O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
Capturing into the ko-shape at the left is a valid move, too.
Admittedly, there is one of these "hot" ko on the board, but it has been created after someone pressed the reset button.
- Click Here To Show Diagram Code
[go]$$B
$$ +----------------
$$ | . Y M Y O X . .
$$ | X X Y O O X . .
$$ | Q X O . O X . .
$$ | M Q O O O X . .
$$ | Q O X X X X . .
$$ | X X X . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]
Please be aware that the corresponding sequence(s) in J89 END HERE!
Until here, J89 has already proven that -- after "pass-for-ko" for ALL of these (earlier) "hot" ko -- re-capturing into these has become valid again.
Going any further would not have made any sense, as the sequence from above would be repeated with reversed colours only.
+++++++++++++++++++++++++SINGLE ko-shapes behave as "usual".
- Click Here To Show Diagram Code
[go]$$B
$$ +------------------
$$ | X . X O . O X . .
$$ | X X O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
A tiny variation of "moonshine life".
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X 1 X O . O X . .
$$ | X X O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
captures into that ko at the top.
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X Q M Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
It results one of these "hot" ko.
- Click Here To Show Diagram Code
[go]$$W pass-for-ko
$$ +------------------
$$ | X Q M Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
Black plays a "pass-for-ko" for that "hot" ko at the top, as he badly wants to re-capture into that ko, in order to take White's stones to the right off the board.
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X Q T Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
The status of that ko at the top has changed to "depends".
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X Q . Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
can only exist on the board as long as there are still
. Seems that someone pressed the reset button.
- Click Here To Show Diagram Code
[go]$$W pass
$$ +------------------
$$ | X Q . Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
There is nothing White could do, so she plays a "pass".
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X Q 4 Q . O X . .
$$ | X X Q O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
is a valid re-capture, as there is NEITHER any of these "hot" ko on the board NOR any of the "depends" type.
- Click Here To Show Diagram Code
[go]$$W pass-for-ko
$$ +------------------
$$ | Y M Y O . O X . .
$$ | X Y O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
White does not want to let her group becoming captured, so she plays a "pass-for-ko" for that just appeared "hot" ko at the top.
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | Y T Y O . O X . .
$$ | X Y O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
The status of that ko has changed to "depends".
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | Y . Y O . O X . .
$$ | X Y O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
Someone pressed the reset button again.
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | Y . Y O 6 O X . .
$$ | X Y O O O O X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]
But White will be unable to re-capture into that ko, as Black is faster.
- Click Here To Show Diagram Code
[go]$$W
$$ +------------------
$$ | X . X . X . X . .
$$ | X X . . . . X . .
$$ | . X X X X X X . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]