:: Igo Hatsuyôron 120 (2020)

Variations of Our Solution (IIIa)

No Early Kikashi

VAR (.4)

: ( 648aa)
Black blocks in the left centre.

: (121 648hn)
White forces with , preparing for further actions below.

We also tried the wedge of , instead, but this will end worse for White.


: ( 125 648ht; 124 648hx)
White attaches in the left centre, but which is not her best option here.

Taking the large point of at the top right, instead, would be better for her. Black would still win the Semeai Variation, but White could capture his large group at the right, as usual.


White might also try Dany's atekomi , but this move is a mistake here, losing one point overall.

:
Black captures White's stone in the upper right.

In principle, Black loses two Main Semeai Liberties by this move. But becomes an approach-move liberty of his group, so the net effect of this move is a loss of one Main Semeai Liberty.

: ( A 648hz;  B 648ia)
White connects her single stone at the upper edge.

Blocking with at the top, or taking territory in the centre, instead, will not affect the final result of the game (i.e. the score in the Capture Variation), but lessen White's loss in the Semeai Variation.

: (136 648ib)
Black destroys White's territorial potential in the left centre.

It would be too early to prevent White's forthcoming throw-in with a move at , instead.

: (138 648ic)
White, on the other hand, has to throw-in just now.

Otherwise, Black will connect. Quite contrary to the subvariation above, Black will gain by this "late" connection, after no valuable endgame spot is remaining outside the Main Semeai.

Black plays 3/5 reductions.

With 5/5 reductions, the final scores would be Jigo / White + 4.

Please assume the rejection of Dany's Sacrifice (, ) played before.

Before her decision point, White will force Black to capture with , and connect at thereafter. This implies that Black will have to also capture at at the end of the game, due to his lack of an eye above.

Capture Variation:

Compared to the superordinate variation ...

  • White's cumulated gain at the upper edge is two points.
  • Black did not capture one White stone in the left centre, so losing one point.
  • Black reduced White's territory in the upper right corner by one point.
  • Black connected his single stone in the lower right, so gaining two points.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Semeai Variation:

At White's decision point, Black's large group in the upper right will have nine liberties, eight direct ones (), and one approach-move liberty ().
White on her side will suffer from the final ko in the upper right centre - found by Joachim ( 648ag) - that depends on the existence of two White cutting points in the centre (), and Black's large ko threat at at the top.
Black's large group in the upper right will not survive the semeai, but Black will capture White's wC-stones in the upper left, and win by about 15 points.

Black will win the game by a large margin.

Copyright © 2020 Thomas Redecker.

Design by Jan van Rongen, modified by Thomas Redecker.

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