: ( 648qt)
White destroys one point of Black's territory in the lower left corner.

:
Black simplifies the matter by blocking immediately.

Pushing for another time at the upper edge with would be useless, as White has the sente push at in the lower left corner for compensation.

In total, Black played 0/1 reduction here.

Capture Variation:

Compared to the superordinate variation ...

• White destroyed one point of Black's territory in the lower left corner.

  White gained one point.

White + 1 => White + 2

Semeai Variation:

Compared to the superordinate variation ...

• Black captured one White stone more in the lower left corner, so gaining one point.

White lost one point.

Black + 1 => Black + 2