Opening problems for AI: Problem 15

Bill Spight · #1

Karigane's opening was rather good. He rarely made more than minor errors. As White in this no komi game he has already made a number of minor errors, but that was not unusual in no komi games, to make the game difficult for Black. His opponent, Takabe Dohei, made a standard play that was a real mistake, losing 12½% to par, according to Elf. The game is GoGoD 1922-12-03a.

Click Here To Show Diagram Code: [go]$$Bcm13 Black to play. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , . . . . . , . . . . . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Bill Spight · #2

Click Here To Show Diagram Code: [go]$$Bcm13 High enclosure $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , a . . . . , . . . . . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , 1 . . . . , . . . . X , . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

As you might have guessed, Black played the enclosure in the bottom left corner.

You might also have guessed that Elf played the AI favorite, the press at a. Not so. But starting with the press could easily transpose into the mainline variation below.

Click Here To Show Diagram Code: [go]$$Bcm13 Elf's mainline $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , . . . . . , . . . . . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . 5 3 . 6 . | $$ | . . . . . . . . . . . . . . 2 1 a . . | $$ | . . . . . . . . . . . . . . . O 4 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Elf chose the reducing play, the side attachment at Q-08. White could reply with the underneath hane at a or the clamp at 15, but prefers the more aggressive 5th line hane, :w14:

.

Click Here To Show Diagram Code: [go]$$Bcm19 Elf's mainline, continued $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O 2 . 4 . . . . . . . O . . . . | $$ | . . . , 1 3 . . . , . . . 5 . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . X X . O . | $$ | . . . . . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . O O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . 6 . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After

Black switches to the press in the top left corner. Then Black plays the press in the top right corner. Finally, White approaches the bottom left corner.

Elf's follow-up on the right side is of some interest, I believe.

Click Here To Show Diagram Code: [go]$$Bcm25 Elf's mainline, III $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O O . O . . . . . . . O . . . . | $$ | . . . , X X . . . , . . . X . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . 9 . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O 4 . | $$ | . . . , . . . . . , . . . . . , 2 1 . | $$ | . . . . . . . . . . . . . 7 X X . O . | $$ | . . . . . . . . . . . . 8 6 O X 5 3 . | $$ | . . . . . . . . . . . . . . . O O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . O . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black sacrifices :b25:

to cut White in two. Then after pushing out into the center, :b33:

attacks the White group in the top right, taking away a potential eye.

Harleqin · #3

Elf's

is certainly something I would hate to play. And even seeing the outcome, I would think that there must be a better way than the hane above at :w14:

.

topazg · #4

I'm nowhere near strong enough to criticise here, but this:

Click Here To Show Diagram Code: [go]$$Bcm13 Elf's mainline $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , . . . . . , . . . . . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . 5 3 . 6 . | $$ | . . . . . . . . . . . . . . 2 1 a . . | $$ | . . . . . . . . . . . . . . . O 4 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Feels like
:w14:

- "Must resist!"
:w16:

- "Hmmm, maybe I need to fix this first"
:w18:

- "Ah, maybe I shouldn't have done that, I ought to connect"

... now if Black's group doesn't end up unpleasantly heavy (which it didn't seem to), I don't understand why White is so happy for the :w14:

/

exchange

Bill Spight · #5

topazg wrote:

I'm nowhere near strong enough to criticise here, but this:

Click Here To Show Diagram Code: [go]$$Bcm13 Elf's mainline $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , . . . . . , . . . . . , X . . | $$ | . . X . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . W . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . 5 3 b 6 . | $$ | . . . . . . . . . . . . . . 2 1 a . . | $$ | . . . . . . . . . . . . . . . O 4 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . X , . . . . . , . . . . X , . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Feels like
:w14:

- "Must resist!"
:w16:

- "Hmmm, maybe I need to fix this first"
:w18:

- "Ah, maybe I shouldn't have done that, I ought to connect"

... now if Black's group doesn't end up unpleasantly heavy (which it didn't seem to), I don't understand why White is so happy for the :w14:

/

exchange

I am not exactly qualified, either, but I checked out some other games, and even took a look at Sakata's Tesuji and Zokusuji of Go after all these years. Here goes:

a is too passive. Black will reply at b.

If 16 Black can simply stand at 14 with sente and I have gotten pushed around.

How about :w14:

first, forcing :b15:

(probably), then :w16:

? Now Black can jump down to the second line, but that's not a problem. So Black turns with :b17:

.

doesn't connect to :wc:

, but to cut it off Black has to sacrifice a stone and make bad shape. In the ensuing fight I am well positioned to run out into the center.

dhu163 · #6

Opening problems for AI: Problem 15

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