: ( 720)
If White now starts the endgame in the upper left with the tsuke of Yamada Shinji 6p, she must be on her guard thereafter.

:
White cannot continue with (worth three points in sente / five points in gote) in the lower left corner, as is usual with the endgame. Black will play tenuki - with - and enforce the Semeai Variation.

Instead, White should capture at 147 (four points in sente) latest now - or with any of here moves in the upper left before - and continue with the endgame at 142 after dissolving the hanezeki.

Black has lost three points in the upper left corner, compared to the "usual" endgame, and does not get the move at 160.

The result is jigo now, instead of a possible white win by two points.

Black has lost four points (compared to the Semeai Variation, shown above, 745), but the result is as good as that in the professional solution. If White wants not to give Black this option, she must play the tsuke of Yamada Shinji 6p in the upper left no later than after (this is before the last atari on her left-side group).