: ( 648ay)
White occupies a liberty of Black's upper group in the left centre.

: (A 648bj)
Black captures White's single stone at the upper edge.

Immediately answering White's move in the centre with connecting at , instead, would be a mistake.

:
White's move threatens a snap-back at .

:
Black has to connect.

:
White blocks at the upper edge.

:
Black continues with the Main Semeai.

:
White chooses Dany's Sacrifice.

If she connected with , instead, she would gain four points in the Capture Variation, but lose two Main Semeai Liberties. Black would have ten Main Semeai Liberties at White's decision point, so she would be unable to capture his large group in the upper right in the Semeai Variation.
Achieving a drawn game in the Capture Variation would mean a loss of two points overall for White.

:
White continues with the Main Semeai.

White is unable to stop Black from creating one point of territory in the left centre. If she played e.g. at , she would lose another Main Semeai Liberty. Again, Black's large group in the upper right would survive the Semeai Variation.

:
Black starts building some additional territory in the left centre.

:
Black connects the ko at the upper edge.

Black must not play any reduction.

Capture Variation:

Compared to the superordinate variation ...

• Black's cumulated gain at the upper edge is two points.
• In the left centre, Black lost three points of territory, but got one, so the net effect is minus two points.

In total, gains and losses compensate for each other.

Black + 4 => Black + 4

Semeai Variation:

Compared to the superordinate variation ...

• Black's cumulated gain at the upper edge is two points.
• In the left centre, Black lost three points of territory, but got one, so the net effect is minus two points.

In total, gains and losses compensate for each other.

White + 2 => White + 2