:: Igo Hatsuyôron 120 (2021)

Variations of Our Solution (Ib)

KataGo's 2021 Solution

VAR (.3) (.5)

: ( 58dr)
White captures Black's stone in the lower left corner.

:
Black is forced to connect.

:
White also connects her two stones in the lower left.

If she connected at , instead, Black would capture at , reverting to the superordinate variation.

: ( 134 58dw)
Black continues in the left centre, in sente.

However, the initial choice of this move followed wishful thinking.
Black has to capture White's single stone in the upper right with , instead.

:
White must connect.

Otherwise, Black would give atari at , and White would be unable to connect at , due to .

However, I overlooked that this connection is also an atari at Black's nakade, enabling White to play her kikashi at in the lower left corner.
If Black did not play at later, White would utilise her central attachment at to destroy Black's potential eye above.

.
Black is able to play the push at the top.

:
Black plays KataGo's connection in the left centre, in order to secure an eye in the left centre.

Alternatively, he could also play at , not affecting the final scores of the game.

: (135 58dx)
White has to connect her stone in the right centre.

Connecting at at the upper edge, saving her single stone there, would be a grave mistake.

:
Black is able to capture at the upper edge.

:
White blocks immediately, not allowing Black to gain further profit outside the Main Semeai area.

:
Black is able to connect.

Black plays 1/1 reduction.

Capture Variation:

Compared to the superordinate variation, ...

  • Black's cumulated gain at the upper edge is two points.
  • Black did not capture White's two stones in the lower left, so losing four points.
  • Black destroyed one point of White's territory in the upper right corner.

In total, White gained one point.

White + 1 => White + 2

Semeai Variation:

Compared to the superordinate variation, ...

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

In total, White lost three points.

Black + 1 => Black + 4

Copyright © 2021 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

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