(Referenced by 812)

: ( 45)
It is not correct for Black to begin with the Hasami-tsuke of .

: (A 168)
Black's push ...

:
... can now be answered by White with a move on the first line, threatening to connect to the left.

:
Black must not play too aggressively here, e.g. with a move at , because he must be sure to keep 13 liberties (; i.e. points that White must occupy in the semeai) for the group in the top right. So, he will be unable to connect the stone at (= ) later.

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Capture Variation:

In the top right corner, White has gained four points (, ), compared to the correct order of moves (with the push, before the hasami-tsuke), so Black wins by one point only.

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You might be curious to know, where the above mentioned condition "13 liberties" comes from. Let us go back to the very beginning of the problem. 13 is the number of liberties that Black's large group has in the top right corner (). These must be occupied by White, if she wishes to take Black's group off the board. At all costs, Black must keep this condition upright that White has to spend 13 moves in this area; otherwise White will have an option that wins her the game.

So Black must avoid taking a liberty of his own group.

As a matter of course, neither , nor , can be counted here. Black has to connect his partial groups in the top right at one of these points.