: ( 648ab)
White prevents Black's kikashi in the hanezeki.
Please note that this move is gote in itself, so White loses one move in the Main Semeai.

: (A 648gd)
Black plays 1/1 reduction.

He does not want to play the atari of in the hanezeki here, as he will end in gote, so losing one move in the Main Semeai.

: (D 648ge)
White continues with the Main Semeai.

She does not want to play her kikashi , in the hanezeki before her decision point.

White will do so only in the Semeai Variation, after her decision point.

Capture Variation:

Compared to the superordinate variation ...

• Black destroyed one point of White's territory in the upper right corner.

White's disadvantage in the Capture Variation is one point.

White + 2 => White + 1

Semeai Variation:

Compared to the superordinate variation ...

• White captured an additional Black stone in the upper right, so gaining one point.
• White captured an additional Black stone at the right, so gaining two points.
• White got an additional point of territory in the hanezeki.

In total, White's advantage in the Semeai Variation is four points.

Black + 4 => Jigo

This implies that Black has to play his own kikashi in the hanezeki "early", if his score in the Semeai Variation is "Black + 2" or less ("White + 1" in the Capture Variation assumed).