:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (IIIb)

Tricking KataGo (Triple-Ko)

VAR (C) (A) (.2) (.2) (.1)

(.1) (.1) (.1) (.1)

(Referenced by 222cg; 222cx)


: ( 222cg)
White connects at the left edge.

:
Black has to give atari immediately.

:
White occupies an inside liberty of Black's cut-off stones.

Alternatively, she might consider playing at , instead, occupying an outside liberty. This choice would result in a change in the order of moves with a later subvariation ( 222dc), not affecting the final result of the game.

:
Black starts the ko fight by capturing in the corner.


Ko:

:
White connects at the top.

:
It is best for Black now to reply to White's ko threat by capturing White's single stone in the right centre, so securing an eye for his large group.

Capturing White's stones in the upper left corner with is out of the question here. If Black did, he would fall prey to the Punishment Semeai.

:
Black occupies a liberty of White's upper string of her left-hand group.

:
White captures the nakade, in order to erase her shortage of liberties that is related to an atari at .

:
Again, Black answers a White ko threat in the right centre.

:
Black's throw-in at the left edge aims at stopping White from giving atari at again.

:
White has to capture the hanezeki's tail now.

Continuing with the ko fight by capturing at , instead, is out of the question here.
White has run out of viable ko threats against Black's right-hand group. Black would capture White's stones in the upper left corner, and thereafter still be able to win the Central Semeai on its own.
White would have to capture the hanezeki's tail anyway, but her loss in the upper left would cost her the game.

:
Black recaptures.

:
White gives atari at Black's cut-off stones, so ending the ko fight in the upper left corner.

:
Black gives atari, simultaneously defending his territory in the left centre.

:
Black starts the ensuing endgame with this large descent in the lower left corner.

...

Capture Variation:

Compared to the superordinate variation ...

  • White captures Black's cut-off stones in the upper left corner, so gaining 16 points.
  • Black's cumulated gain in the lower left corner is four points.
  • Black's cumulated gain in the nakade area is five points.
  • Black destroyed five points of White's territory in the upper right corner.
  • Black's cumulated gain in the right centre is five points.
  • White did not capture Black's stone in the lower right, so losing two points.

In total, White lost one point.

White + 7 => White + 6

Copyright © 2021 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

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