: ( 648aa)
White plays Dany's atekomi.

Please note that this move is played outside the Main Semeai, but does not lose a tempo therein, because becomes an approach-move liberty of White's group at the left.

Black is still par with the Punishment Semeai Liberty Level.

Black is unable to continue with , or , in the left centre, because any of these moves would push him below the Punishment Semeai Liberty Level.
On the other hand, White threatens the severe cut at , which would win her the game.

Black is strictly bound to continue with the Main Semeai. Therefore, giving atari at is his only choice, because this move is the only one that also defends against White's cut at (which White will not play now; please refer to this subvariation 648of for details).

White will connect at , providing Black with two Main Semeai Liberties. Now, Black is able to defend against White's cut at .

We ask for your kind understanding that we felt unable to adjust the move numbers (i.e. to increase these by two) in the already created diagrams, which follow in this part of the variation tree.

:
Black intends to start Dany's Ko.

Black's atari is played outside the Main Semeai, and so loses a tempo therein.

:
White creates a ko shape.

Again, her move is played outside the Main Semeai, but creates another approach-move liberty for her left hand group at C. White does not lose a tempo.

(Referenced by 648im)

:
Black captures the ko in the centre.

Black's move is played outside the Main Semeai, and so loses a tempo, in principle. However, White's two approach-move liberties vanished with this move, so the net effect on the Main Semeai Liberties is plus one.

:
White captures the nakade as a ko threat.

Black is at nine Main Semeai Liberties now.

Winning the ko will require two White moves at (capture), and at (connect). Both of White's approach-move liberties will become effective again, so the net effect on the Main Semeai is zero.

Black, however, will lose a tempo in the Main Semeai by his connection at , should he be able to win the ko.

Please note that - from now on - we will not update the board's border colour after moves that capture the ko in the left centre, as long as this ko fight is still active, and undecided.

:
Black connects, erasing his potential shortage of liberties in this area.

:
White plays her kikashi in the lower left corner.
This move loses one tempo in the Main Semeai, but gains one point overall, because Black will have to play an additional defensive move in the corner, after White won the ko in the centre.

: ( A 648oa)
White blocks at the top, in an attempt to reduce the number of Black ko threats in this area.
This move loses a tempo, as it is played outside the Main Semeai area. Black is four over par now. Please remember that the calculation of Main Semeai Liberties is based on the presumption that White will win the ko fight, and connect the ko.

Counter-intuitively, connecting at is better for her.
As it turns out, White has sufficient surplus of valid ko threats here, allowing her to prioritise territory over ko threats.

Ko: ; ; ; ; ;

; :
These ko threats cost one tempo in the Main Semeai each. Eventually, Black is two over par.

:
Black does not have any valid ko threat left, so he captures White's single stone at the upper edge.

: (A 648ob)
White blocks at the upper edge.

She might consider connecting the ko just now, but this will allow Black to win the Semeai Variation.

:
We will end the ko fight here, so Black continues with the Main Semeai.

The points of lA and lB can be considered as a double-ko,

Black plays 1/2 reductions.

Black will connect the ko at , White the ko at .

Black will have to capture at before the end of the game.

Capture Variation:

Compared to the superordinate variation ...

• White got an additional point of territory at the top.
• Black did not get any territory in the left centre, so losing one point.
• Black destroyed three points of White's territory in the upper right corner.

In total, White lost one point.

White + 2 => White + 1

Semeai Variation:

Compared to the superordinate variation ...

• White got an additional point of territory at the top.
• Black did not get any territory in the left centre, so losing one point.
• White captured an additional three Black stones in the upper right, so gaining three points.

In total, White gained five points.

Black + 4 => White + 1