FLAG 8a: ( 1036)
A shared ko in the centre is possible with a smaller eye for Black only. The sequence from to is one option for construction.

Compared to main line (with a larger eye for Black, after White's move at , and Black's moves at , and ), there will be no effect. Black will still need one external ko-threat. Compared to the smaller eye for Black alone, Black needs one external ko-threat less.

FLAG 8a1: ( 1040)
Please note that White must be on her guard not to fill-in her second false eye in the centre, at , before starting the ko.

FLAG 8a2: ( 1043)
Also, White must not play from below, at , to create a smaller eye for Black. Unnecessarily, she would need an own ko-threat to win the game!

FLAG 8a3: ( 1045)
Playing from below, with a move at , does not make a difference, only in the case that Michael Redmond's kikashi in the bamboo joint ( / ) has not been played already.

FLAG 8b: ( 1047)
In the case of the shared ko in the centre, Black might allow White to play at , resulting in an additional external ko on the upper edge.

But Black must not do so, because White will win by double-ko.

Please note that there is a precondition that Black needs to play a protective move in the upper left corner, to enable wholly approaching White's centre group.

FLAG 11: ( 1068)
(Referenced by 981)

White's solid move at , in an attempt to simplify the matter, is not possible with Michael Redmond's kikashi in the bamboo joint ( / ) being not played already. This means that White's options in the centre are limited then.