:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (IIIb)

Tricking KataGo (Triple-Ko)

VAR (C) (A)

: ( 222aa)
Black plays the guzumi.

The continuation is not that trivial. Both sides must be on their guard here.

:
White's push at the left edge is absolute sente.

White could have done without this move.
Black is unable to block with immediately, so White could have played her push also after a Black reinforcement of his upper left corner, e.g. with or .

:
Black reinforces his upper left corner.

He must not live independently at the right, with a move at , instead. White would continue with , capturing five of Black's stones in the corner. In addition, White would gain about 25 points, because the dissolving of the hanezeki would be no longer mandatory for her.

:
White answers Black's guzumi locally.

: ( C 222nc)
Black has to give atari at White's two stones in the lower left just now.

However, he would gain in the Semeai Variation, if he occupied another liberty of White's left-hand group, instead.

Black is par with the Punishment Semeai Liberty Level, so playing any of the large endgame moves of , or , is out of the question. The same is true for , capturing White's single stone in the upper right centre.

:
White has to start the endgame at the left side of the board "early".

: (B 222ne C 222nh ; 118 222nm)
Black connects.

Alternatively, he might consider playing the large endgame move of at the upper edge. The final scores will remain unaffected, compared to the correct line below.

Capturing White's stones in the lower left or White's single stone in the upper right, however, would be a tiny mistake, as White would be allowed to also win the alternative Main Variation.

: (C 222nn)
White continues with the Main Semeai.

She would lose two points overall, if she connected her two stones in the lower left, instead.

:
White continues with the Main Semeai.


: ( 127 222nq)
Latest now, White must play the wedge in the left centre, in order to gain one point overall.


:
Black defends his territory in the left centre.

Black must not play any reduction.

After her decision point, White will play the hene of at the upper edge.
Black will exchange for , and must connect at later. White will connect at .

Capture Variation:

Compared to the super²ordinate variation ...

  • White's cumulated gain in the upper left is seven points.
  • White's cumulated gain in the lower left is two points.
  • White did not capture Black's stone at the lower edge, so losing two points.
  • Black's cumulated gain in the upper right is seven points.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Semeai Variation:

Compared to the super²ordinate variation ...

  • White's cumulated gain in the upper left is seven points.
  • White's cumulated gain in the lower left is two points.
  • White did not capture Black's stone at the lower edge, so losing two points.
  • In the upper right corner, White lost four points of territory, but captured an additional two Black stones, so the net effect is zero.
  • Black captured an additional two White stones at the left, so gaining four points.

In total, Black lost three points.

Black + 3 => Jigo

Copyright © 2021 Thomas Redecker.

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