:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (Ib)

KataGo's 2021 Solution

VAR

: ( 58aa)
We inserted Black's guzumi manually, and let KataGo play a selfplay game thereafter.

The alternative options mentioned below were identified by browsing through this selfplay game in "Analysis Mode".

:
Black's previous move was gote, so White is able to solidify her shape at the bottom, securing independent life for her group there.
Simultaneously, she attacks Black's potential territory in the lower left corner.

Alternative option is , completing the Guzumi Exchange.

:
Black is forced to secure independent life for his large group at the right, as White can block the growth of the hanezeki's tail with ease now.

:
Thereafter, it is White, who must save her stones at the left. She starts with giving atari at Black's single stone below.

:
Black connects his five stones at the left edge with this lower left corner.

:
White captures Black's single stone.

:
Black strengthens his formation in the upper left centre, threatening to capture White's stones at the left.

:
White secures the connection of her stones at the left with those at the top.

:
Finally, Black defends his lower left corner.

:
White captures Black's single stone at the upper edge, in sente.

:
Black blocks, as a matter of course.

:
White starts her manoeuvres to secure territory in the centre ...

:
... and at the top.

:
Black's solid connection threatens to separate White's group at the left, utilising the sequence , , .

:
White connects in the lower left corner, sacrificing another stone for creating independent life for her group at the left.

:
Black gives atari at White's three stones.

Alternative option (CHITOOM) is , followed by , .

:
White's connection is forced.

:
Alternative option (CHITOOM) is .

:
Alternative options are , and .

:
White plays the hane at the upper edge.

Alternative options (CHITOOM) are and .

:
White captures Black's single stone, threatening to start a ko-fight by cutting at , instead of solidly connecting with ,

Alternative option is .

:
Alternative option is .

:
Black captures into the ko-shape at the upper edge.

Alternative option is , followed by , .

:
White connects her single stone in the centre.

:
Black reduces White's territory at the bottom in return.

Alternative option is .

:
White defends her territory in the centre.

Alternative options are , and .

:
White captures the ko at the upper edge.

:
Black connects solidly, securing his territory in the upper left corner.

Alternative option is , with a better winrate displayed.

:
White gives atari in the centre.

Alternative options are and .

:
Alternative option is .

:
Black starts the reduction of white's territory at the bottom.

:
White connects her single stone in the right centre in return.

:
Black solidifies his formation in the upper left centre.

Alternative options are and .

:
Alternative options are and .

:
Alternative option is .

:
Alternative option is .

:
Alternative option is .

:
Alternative option is .

:
Alternative option is .

:
Alternative option is .

:
Alternative options are , , and .

...

:
Alternative option is .

:
Alternative option is , with a better winrate displayed.

:
Alternative options are and .

:
Alternative options are and .

:
Alternative option is .

:
Alternative option is .

:
Alternative option is .

...

Black has 29 points of territory and 16 prisoners, adding up to a total of 45 points.

White has 30 points of territory and 16 + one (the Black stone assumed to have been taken before the problem's setup) prisoners, resulting in a total of 47 points.

White wins the game by two points.

Copyright © 2021 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

L e g a l   n o t i c e