Variations of Our Solution (Ib)
KataGo's 2021 Solution
VAR (.3) (.3)
(Referenced by 58aa; 58ai; 58dc) : ( 58bb) However, this move is the game-deciding mistake here (correct continuation below provided), compensating for White's earlier mistake of having connected at too early. Black's defensive move in the left centre does not occupy a liberty of White's left-hand group, and so loses one decisive tempo in the Main Semeai. Contrary to a subvariation discussed later ( 58dc), Black's upper left corner is still open here. However, Black's loss of one Main Semeai Liberty will make the inside atari after White's forthcoming crosscut mandatory, losing one point overall. | |
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: : ; : : : (A 58cu) Playing the outside atari of , instead, would be a mistake here, due to Black's earlier move at in the centre that cost him a decisive tempo in the Main Semeai. | |
: : (Referenced by 58aa) : Please remember that this choice benefits White by four points in the Semeai Variation (correct continuation below provided), while not affecting the overall result of the game. : : | |
: : ( 143 58cv) This move will increase the susceptibility to errors in the following course of the game unncessarily, and so can be considered to be a technical mistake in the timing of moves. White should play the wedge in the right centre first, in sente. : If he played at the left side of the board, instead, it would result a change in the order of moves with the previous subvariation. | |
In order to defend her potential territory in the upper right, White needed four moves (). Black needed five moves () to accomplish the same task at the left side of the board. It's White's turn, so after all defensive moves were played in order, there would remain one hole in the encirclement of Black's territories. Please note that both sides already played one protective move each in the upper right. Please also note that Black is unable to connect his stone in the lower right, as this would lose two tempi in the Main Semeai - but he has none to spend. | |
White has five territory-destroying moves at the left side of the board (), all gaining one point (in the Capture Variation). Black would be able to destroy four points of White's territory in the upper right, and has the connection of in the lower right at his hands, which is worth two points. This implies that White must never start the mutual reduction of opponent's territory. | |
: : : ( A 58cw) White must continue e.g. with , instead. White's mistake seems to be similar to another line, where White mistakenly did not capture Black's stone in the lower left corner, but thoughtlessly occupied one of Black's liberties at the right. : | |
Black must not play any reduction. | |
Capture Variation: Compared to the superordinate variation, ...
In total, gains and losses compensate for each other. White + 1 => White + 1 | |
Semeai Variation: Compared to the superordinate variation, ...
In total, White gained eight points. Black + 7 => White + 1 | |