:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (IIIb)

Tricking KataGo (Triple-Ko)

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

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

: ( 222cg)
Black bumps at the top, without having played the throw-in in the right centre before.

:
White connects at the top.

She might consider inserting the exchange of for in the upper left corner before, not affecting the outcome of the game.

: ( 126 222cp)
Black captures White's single stone in the right centre immediately, but which is a mistake here.

Unless the (reverse) komi isn't much larger (at least -10 points) than the draw komi for this position (-5 points), KataGo will not favour the correct throw-in at .

:
White's connection in the right centre is decisive, largely affecting the character of the Central Semeai.

: (129 222cq)
Black forces in the centre.

Descending to at the upper edge will result in a change in the order of moves.

: (C 222cr)
White must push in the centre now, threatening to destroy Black's eye there.

If she mistakenly also descended to at the upper edge, she would give Black the opportunity to achieve a much better result than here.

:
Black threatens to connect along the upper edge.

Playing at , instead, would result in a change in the order of moves.

: (136 222ct)
Black connects to the left.

Alternatively, he might consider connecting his hasami-tsuke stone with .

: (A 222cu)
White has to start the ko fight in the upper left corner as early as possible. This is the latest moment to do so.

If she continued with occupying Black's liberties at the right, e.g. with , she would allow Black to achieve a much better result than below.


Ko:

(Referenced by 222cn)


:
Black takes a liberty of the upper string of White's group at the left.

By playing the kikashi of in the hanezeki, instead, Black would take his right-hand group a liberty (with regard to the Central Semeai), due to White's connection at .

Playing the kikashi of , , instead, is useless, as this exchange would provide White with an own ko threat at , forcing Black to occupy a liberty of his group again with .

:
White captures the nakade, temporarily erasing her shortage of liberties that stops her from occupying the point of above.


Ko: ;

:
White chooses an indirect way to occupy one of Black's liberties.

:
White has got an additional ko threat in the hanezeki.


Ko:

:
Black does not have any viable ko threat left, so he has to connect the hanezeki's tail.

:
White occupies the fifth remaining liberty of Black's connected bottom group.

Black remains helpless.
If he continues with the Central Semeai by occupying another shared liberty at , White will recapture the ko in the upper left with , and thereafter give atari at .
If Black connects the ko with , White will continue with in the left right, winning the semeai with Black's bottom group.

White will win the game by a very large margin.

Copyright © 2021 Thomas Redecker.

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