Life In 19x19

Posted: **Fri Jun 26, 2020 10:53 am**

Todays's position is from GoGoD 1992-11-17a, the 2d Ing Cup semi-final, game3, between Otake Hideo (W) and Rui Naiwei. Otake made a fine move for the time, but Elf reckons that it lost 13% to par.

Click Here To Show Diagram Code: [go]$$Wcm12 White to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . . . O . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . . . . , . . . . . , O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Fri Jun 26, 2020 10:54 am**

Click Here To Show Diagram Code: [go]$$Wcm12 Pincer, then mainline variation $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . . . O . . . . a . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . B . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 4 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 1 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 2 X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . . . . , . . . . . , O . . | $$ | . . . . . 5 . . . . . . . 3 . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Otake played the pincer,

. Then Elf recommends the solid connection,

.

extends on the bottom side, and then

plays a counterpincer. From the pre-AI perspective, White can be satisfied to have prevented Black from making an ideal extension on the right side, and

plays elsewhere.

However, the bots do not consider that extension to be ideal, and often omit it. In this case, instead of

at

, Elf's choice is

and after White extends to

, for Black to make the enclosure at a instead of extending on the right side.

Click Here To Show Diagram Code: [go]$$Wcm12 Cut, mainline variation $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . 9 . . . . | $$ | . . . . O . . . O . . . . . . . 7 . . | $$ | . . X , . . . . . , . . . . . X 5 . . | $$ | . . . . . . . . . . . . . . . 8 6 . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . 4 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 2 . . | $$ | . . . . . . . . . . . . . . 3 1 X . . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . . . . , . . . . . , O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Elf prefers the cut. Then

pulls back and

stands. After

,

attaches at R-16 instead of invading at R-17, presumably to prevent Black from blocking that invasion at R-17. I expect that the White extension on the top side is one reason for that decision.

Posted: **Fri Jun 26, 2020 11:43 am**

Posted: **Fri Jun 04, 2021 10:10 am**

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