:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (IIIb)

Dany's Ko: Joachim's No-Ko-Threats

VAR (.1)

: ( 648qc)
White jumps to the upper 1-2-point.


Ko: ; ; ; ; ;

:
Black answers by occupying the other 1-2-point.

: ( 181 648qf)
Black continues with the ko fight.

However, he would be one point better in the Semeai Variation, if he terminated the ko fight latest now.

:
White plays her fourth ko threat in the upper left.

: (168 648qg)
Black separates White's invaders.

Black is unable to connect the ko, instead.

; : (184 648qh)
Please understand these two moves as replacement for White's kikashi , in the centre, which had been played too early by us.

It would be too early to play the outside atari in the upper left, instead. The overall result of the game would not be affected, but White would be unable to win the Semeai Variation.

:
White's atari from the outside is her fifth ko threat in the upper left, now played at the the right time.

: (168 648qj)
Black connects.

So very late in the game, Black is unable to ignore White's ko threat.

:
Black does not have any valid ko threat left, and so captures White's stone in the upper right.

:
White connects the ko in the left centre.
Please note that she has one ko threat left, at .

:
The Main Semeai continues.

Black plays 1/3 reductions.

Before the end of the game, Black will have to capture at in the lower left corner.

Capture Variation:

Compared to the superordinate variation ...

  • White's cumulated gain in the upper left corner is one point.
  • Black destroyed an additional point of White's territory at the top.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Semeai Variation:

Compared to the superordinate variation ...

  • White's cumulated gain in the upper left corner is one point.
  • White captured one Black stone more at the upper edge, so gaining one point.
  • Black captured one White stone more in the upper left, so gaining two points.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Copyright © 2021 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

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