(Referenced by 251; 258)

: ( 243)
White captures Black's nakade stones on the left side in the proper way. This move takes a liberty from Black's group, and simultaneously closes the gap towards the lower edge. The importance of both aspects will become evident soon.

In principle, a protective move on the left side loses a move with the semeai on the right side of the board. Only this one here is alright for White - despite the fact that Black also lost a move with his preceding protective move at - because it takes the amount of Black's remaining ko-threats in this area into account.

, :
Both sides follow the main line of Joachim's Ko-Semeai ( 225).

:
White starts the ko-fight "early".
White has lost all of her ko-threats in the upper left corner, so starting the ko "late" (e.g. when her centre group is reduced to five liberties) will not work here, too.

Ko: ; ; ; ;

, :
Here also, Black can still use his ko-threats in the hanezeki.

:
However, on the left side of the board, Black has got only two ko-threats. Now, all of White's partial groups there have four liberties - against two liberties for Black's nakade stones - so that Black cannot threaten any of these even with two moves in a row.

:
White captures the ko for the last time. Her centre group has more than four liberties, so neither nor are valid ko-threats for Black. White will win with ease.
It will be shown within the sub-variations after Michael Redmond's kikashi in the bamboo joint ( 419) that no other capturing move on the left side but will do the job here. Further details on this subject can be found even later ( 841).