: ( 649aa)
White blocks at the top, pre-empting a Black move at the same point.

:
Black reduces White's territory at the upper edge.

:
The Main Semeai continues.

:
White stops Black from playing at , so creating profit outside the Main Semeai area, what would benefit him by two points in the Semeai Variation.

Black plays 1/1 reduction.

Capture Variation:

Compared to the superordinate variation ...

• Black got one point of territory less in the left centre.
• Black destroyed one point of White'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 ...

• Black got one point of territory less in the left centre.
• White captured an additional Black stone in the right centre, so gaining one point.

In total, White gained two points.

Black + 6 => Black + 4