:: Igo Hatsuyôron 120 (2022)

New Story Line 2022

Joachim's Hiki at the Upper Edge

(Joachim's Ko-Semeai #1)

VAR

: ( 2034)
Black captures White's single stone in the right centre, securing an eye for his large group.

:
White occupies the Guzumi Point, preventing independent life for Black's group.

For further details of our earlier analysis, please refer to the history of our investigations ...
225
... and ...
312
... and ...
321

Please note that we utlisised a different order of moves at that time.

:
Black's throw-in creates a false eye in White's formation, so gaining one additional liberty in the forthcoming semeai.

:
Here in this subvariation, Black attacks White's eye space at the top from the left first.

:
White connects.

:
Black creates another false eye in White's formation.

:
White's bump at the top is sente, threatening to continue with the descent to .
The points of and would be miai thereafter, securing life for White's centre group.

:
Black defends against White's threat with a hane at the first line.

:
White reduces the size of Black's eye in the right centre.

:
Black creates a ko-shape at the right edge, ...

:
... in sente.

:
Now, Black defends his eye.

:
White has to answer with the atari.

:
Black intends to create another ko-shape in the right centre.

:
White simplifies the issue here.

Alternatively, she might also choose the atari of , resulting in the second ko-shape in the right centre.

:
KataGo starts the ko-fight "early".

Please note that in this subvariation White would be able to start the ko-fight "late", i.e. after the mutual occupation of most of the outside liberties of both groups that are engaged in the semeai.

For further details of our earlier analysis, please refer to the history of our investigations ...
321


Ko:

:
KataGo chooses a ko-threat at the left side of the board.

:
White utilises her so far unused push into Black's upper left corner.

:
Black plays a defensive move, threatening to lead his nakade stones out into the open.

He would have had far more ko-threats on the left side of the board, if he played himself.
Apparently, KataGo realises that a ko-fight would not lead to success, and so would be a waste of time.

:
White immobilises Black's nakade stones, securing independent life for her group at the left.

:
Black continues the semeai with White's centre group, without recapturing into the ko at the upper right.

:
Finally, White connects this ko.

:
Black continues with the mutual occupation of opponent's liberties.

:
Black puts his last hopes on the connection of the hanezeki's tail.

:
White's oki is forced.

:
KataGo inserts some kikashi on the left side of the board.

:
White occupies Black's last outside liberty.

:
White occupies the last but one shared liberty of the semeai

:
Black is unable to give atari at , because White would capture his large group with wlB.

Black's connected hanezeki group at the bottom is dead, as White could take it off the board, starting with a move at .

White will win the game by a very large margin.

2034

Copyright © 2022 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

L e g a l   n o t i c e