( 986)

(Referenced by 312; 347)

To construct a shared ko in the centre, we have to take the / stones off the board. This implies that we first assume here that Michael Redmond's kikashi in the bamboo joint has not been played.

:
The sequence from to establishes the desired shape in the centre - and serve the purpose to give the previous moves a more realistic look only. But now, Black is far below the Punishment Semeai Liberty Level, so we have to shift Black's -stone.

Here, Black has occupied an outside liberty, with , instead of a shared one. White's group has five liberties (w, 3 * c, j), Black's group has seven liberties (3 * c, j, 2 * b, k).

:
White's centre group does not have five "real" liberties (the one in the centre depends on ko), so Black could connect the hanezeki's tail here. This is not as trivial as it looks like, so will show first, what happens if Black gives atari in the hanezeki at too early, instead.

@ ; Ko:

:
Black connects the hanezeki's tail with .

:
Black needs one external ko-threat to win.

Ko:

:
We get the same result as with Black's larger eye in the main line.

This is one ko-threat less than with the smaller eye alone. The additional shared ko in the centre makes up for one Black ko-threat.