About compositions of three ko-shapes (contd)##### ASYMMETRICAL triple-ko cycles #2 #####
- Click Here To Show Diagram Code
[go]$$B
$$ ? ? ? ? ? ? ? ? ? ? ? ?
$$ ? ? ? ? ? ? ? ? ? ? ? ?
$$ ? ? X X X X X X X S ? ?
$$ ? ? X O X O X c X X ? ?
$$ ? ? O a O b O X O C ? ?
$$ ? ? O O O O O O O ? ? ?
$$ ? ? ? ? ? ? ? ? ? ? ? ?
$$ ? ? ? ? ? ? ? ? ? ? ? ?[/go]
Let's add ONE EYE to ONLE ONE of the GENUINE triple-ko's groups, as well as a SHARED liberty.
- Click Here To Show Diagram Code
[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . ? ? ? ? S . . . . . . . |
$$ | . . . . . . . ? O W . ? . . . . . . . |
$$ | . . . , . . . ? . . X C . . . , . . . |
$$ | . ? ? ? ? S . ? ? ? ? ? . ? ? ? ? S . |
$$ | . ? O . . ? . . . . . . . ? . O . ? . |
$$ | . ? . X B C . . . . . . . ? B . X C . |
$$ | . ? ? ? ? ? . . . . . . . ? ? ? ? ? . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . : . . . . . , . . . |
$$ | . ? ? ? ? S . . . . . . . ? ? ? ? S . |
$$ | . ? W . O ? . . . . . . . ? . O W ? . |
$$ | . ? . X . C . . . . . . . ? X . . C . |
$$ | . ? ? ? ? ? . . . . . . . ? ? ? ? ? . |
$$ | . . . . . . . ? ? ? ? S . . . . . . . |
$$ | . . . , . . . ? . . O ? . . . , . . . |
$$ | . . . . . . . ? X B . C . . . . . . . |
$$ | . . . . . . . ? ? ? ? ? . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+
$$ {AR M17 Q15}
$$ {AR Q12 Q9}
$$ {AR D9 D12}
$$ {AR D15 H17}
$$ {AR Q6 M3}
$$ {AR J2 J1}
$$ {AR K2 K1}
$$ {AR L2 L1}
$$ {AR H3 D6}[/go]
This diagram shows a triple-ko cycle that is similar to the GENUINE one.
The marked stones are those that have been played last.
However, both sides are free to leave the cycle shown
(symbolised by the "triple-arrow" at the bottom of the diagram).
This exit can be taken at every position of the cycle. We chose the bottom one for an exemplary case of a status assessment for a Black group first.
--------------------------------------------
- Click Here To Show Diagram Code
[go]$$B Status assessment for BLACK groups
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . Y . . . . . Q . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . ? ? ? ? S . . . . . . . ? ? ? ? S . |
$$ | . ? W . . ? . . . . . . . ? . . O ? . |
$$ | . ? . X X C . . . . . . . ? X X . B . |
$$ | . ? ? ? ? ? . . . . . . . ? ? ? ? ? . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . Y . . . . . , . . . |
$$ | . ? ? ? ? S . . . . . . . ? ? ? ? S . |
$$ | . ? . . . ? . . . . . . . ? . . O ? . |
$$ | . ? X X B C . . . . . . . ? X X . ? . |
$$ | . ? ? ? ? ? . . . . . . . ? ? ? ? ? . |
$$ | . . . . . . . . . . . . . a s y m m . |
$$ | . . . , . . . M M M M M . . o n e . . |
$$ | . . . . . . . M e n d M . . . . . . . |
$$ | . . . . . . . M M M M M . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+
$$ {AR K16 F8}
$$ {AR D9 D12}
$$ {AR D15 D16}
$$ {AR J19 J18}
$$ {AR K19 K18}
$$ {AR P12 P9}
$$ {AR Q12 Q9}
$$ {AR R12 R9}
$$ {AR F14 O13}
$$ {AR L19 L18}
$$ {AR C18 C19}
$$ {AR D18 D19}
$$ {AR E18 E19}
$$ {AR K16 O14}
$$ {AR K16 K11}
$$ {AR K9 K4}[/go]
White plays

outside the cycle. Black has three options now.
LEFT:
captures into the remaining ko.

has to capture into one of the other ko-shapes, as Black's move was an atari.

-- option 1: is played outside the triple-ko, as there is no ko-shape remaining Black could capture in.
This returns into the OPTIONAL cycle.
Both sides exchanged one move each outside the triple-ko, what they could have done anyway.
-- option 2: occupies the SHARED liberty, creating the MIRRORED version of
RIGHT.
This option is the ADVISABLE one.
RIGHT:
occupies the SHARED liberty.
This exits to ASYMMETRICAL triple-ko cycles #1.
This option is the ADVISABLE one.
MIDDLE:
is played outside the triple-ko.
This is a clear sign that Black does not want to continue the triple-ko cycle.
Both sides exchanged one move each outside the triple-ko, what they could have done anyway.
--------------------------------------------
- Click Here To Show Diagram Code
[go]$$Bc Status assessment for WHITE groups
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . ? ? ? ? S . . . . . . . |
$$ | . . . . . . . ? O W . ? . . . . . . . |
$$ | . . . . . . . ? . . X C . . . . . . . |
$$ | . ? ? ? ? S . ? ? ? ? ? . ? ? ? ? S . |
$$ | . ? O . . ? . ? ? ? ? S . ? . O . ? . |
$$ | . ? . X B C . ? O O . ? . ? B . X C . |
$$ | . ? ? ? ? ? . ? . . X B . ? ? ? ? ? . |
$$ | . . . . . . . ? ? ? ? ? . . . . . . . |
$$ | . . . , . . . ? ? ? ? S . . . , . . . |
$$ | . ? ? ? ? S . ? O O . ? . ? ? ? ? S . |
$$ | . ? W . O ? . ? . . X ? . ? . O W ? . |
$$ | . ? . X . C . ? ? ? ? ? . ? X . . C . |
$$ | . ? ? ? ? ? . . . . . . . ? ? ? ? ? . |
$$ | . . . . . . . ? ? ? ? S . . . . . . . |
$$ | . . . , . . . ? . . O ? . . . , . . . |
$$ | . . . . . . . ? X B . ? . . . . . . . |
$$ | . . . . . . . ? ? ? ? ? . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+
$$ {AR M17 Q15}
$$ {AR Q12 Q9}
$$ {AR Q6 M3}
$$ {AR H3 D6}
$$ {AR D9 D12}
$$ {AR D15 H17}
$$ {AR J15 J14}
$$ {AR K15 K14}
$$ {AR L15 L14}
$$ {AR K11 K10}
$$ {AR J11 J10}
$$ {AR L11 L10}[/go]
-- option 1: occupies the SHARED liberty.
This exits to ASYMMETRICAL triple-ko cycles #1.
This option is the ADVISABLE one.
-- option 2:
(not displayed in the diagram for the sake of clarity) is played outside the triple-ko cycle.
White will capture into the remaining ko-shape, effectively returning to the main diagram of ASYMMETRICAL triple-ko cycles #2, as is shown with LEFT for the status assessement for WHITE groups (with colours interchanged).
--------------------------------------------
The presentation of the entire ASYMMETRICAL triple-ko cycle #2 might look like the following diagram.
- Click Here To Show Diagram Code
[go]$$W
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . ? ? ? ? S . . . . . . . |
$$ | . . . . . . . ? O W . ? . . . . . . . |
$$ | M M M M . . . ? . . X ? . . . M M M M |
$$ | M ? ? ? ? S M ? ? ? ? ? M ? ? ? ? S M |
$$ | M ? O . . ? M . . . . . M ? . O . ? M |
$$ | M ? . X B ? 1 . . . . . 1 ? B . X ? M |
$$ | M ? ? ? ? ? . . ? ? ? . . ? ? ? ? ? M |
$$ | M M M . M M . . ? ? ? . . M M . M M M |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . ? ? ? ? S . . . . . . . ? ? ? ? S . |
$$ | . ? W . O ? . . . . . . . ? . O W ? . |
$$ | . ? . X . ? . . . . . . . ? X . . ? . |
$$ | . ? ? ? ? ? . M . 1 . M . ? ? ? ? ? . |
$$ | . . . . . . M ? ? ? ? S M . . . . . . |
$$ | . . . , . . . ? . . O ? . . . . . . . |
$$ | . ? ? ? . . M ? X B . ? M . . ? ? ? . |
$$ | . ? ? ? . . M ? ? ? ? ? M . . ? ? ? . |
$$ | . . . . . . . M M M M M . . . . . . . |
$$ +---------------------------------------+
$$ {AR M17 Q15}
$$ {AR Q12 Q9}
$$ {AR Q6 M3}
$$ {AR H3 D6}
$$ {AR D9 D12}
$$ {AR D15 H17}
$$ {AR J15 K12}
$$ {AR D6 C3}
$$ {AR C3 C6}
$$ {AR R6 R3}
$$ {AR R3 Q6}
$$ {AR K12 L15}
$$ {AR F13 J11}
$$ {AR J11 F12}
$$ {AR O13 L11}
$$ {AR L11 O12}
$$ {AR J5 K11}
$$ {AR K11 L5}[/go]
You will easily have realised that White can leave the cycle ONLY ONCE, while Black can do so whenever and as often as he likes.
_________________
The really most difficult Go problem ever:
https://igohatsuyoron120.de/index.htmIgo Hatsuyōron #120 (really solved by KataGo)