: ( 648qe)
White gives atari in the upper left, utilising her fifth ko threat in this area.

Ko:

:
Black connects the ko in the left centre.

:
White captures in the upper left.

:
Black is forced to connect at the left edge, also capturing one of White's stones in the corner.

: (184 648qi)
White continues with the Main Semeai.

Fighting the ko until the very end, instead, would be a grave mistake.

:
Black recaptures the ko.

:
White still continues with the Main Semeai.

:
Finally, Black connects the ko.

Black plays 0/1 reduction.

Capture Variation:

Compared to the superordinate variation ...

• White destroyed one point of Black's territory in the upper left corner.
• Black's cumulated gain in the left centre is two points.
• Black's cumulated gain in the lower left corner is one point.
• White got an additional point of territory at the upper edge.
• White destroyed one point of Black's territory in the right centre.

In total, gains and losses compensate for each other.

White + 2 => White + 2

Semeai Variation:

Compared to the superordinate variation ...

• White destroyed one point of Black's territory in the upper left corner.
• Black's cumulated gain in the left centre is two points.
• Black's cumulated gain in the lower left corner is one point.
• White captured one Black stone less at the upper edge, so losing one point.
• White captured one Black stone less in the left centre, but got one additional point of territory there, so the net effect is a one point gain for Black.

In total, White lost four points.

White + 2 => Black + 2