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Shapes to remember (SDK level)

https://www.lifein19x19.com/viewtopic.php?t=16894

Page 9 of 12

Re: Shapes to remember (SDK level)

Posted: Wed Apr 06, 2022 1:49 pm
by Knotwilg
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . 8 7 3 5 . . . . . |
$$ | . . X O . . . O d . 6 X W 4 . X O . . |
$$ | . . X O . . . . . c X O 1 . . X O . . |
$$ | . X O O . . . . . . b 2 9 . . X . . . |
$$ | . X . . . . . . . . e a 0 . . . . O . |
$$ | . . X . O X . . . . . . . . O . O . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . O X O . X . . . . . . . . . . . . |
$$ | . . . X O . . . . , . . X O O O . . . |
$$ | . . X . O . . . . . O O O X X X . . . |
$$ | . . . O . X . . . . O X X . . . . . . |
$$ | . X O . . . . . . . . . . X . . . . . |
$$ | . X . X . . . . . . . X . . . . O . . |
$$ | . . . X . . . . . O . . . . . . . . . |
$$ | . . X , O . . . . O X . . O O O . . . |
$$ | . . . X O . . O O X X . X X O X O O . |
$$ | . . . . . . . . . O X . . . X X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Anything allowing White to solidly connect looks wrong, so ...

Not that I read it but White can't hane at :w10: because of the ladder. So probably :w8: is better as a lateral stretch.

Re: Shapes to remember (SDK level)

Posted: Thu Apr 07, 2022 7:22 am
by jlt
Hint
Don't play 1-2-3, just play 3.
Katago's main line
Click Here To Show Diagram Code
[go]$$Bc Katago's main line (11 at a and 12 at b)
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . 3 . 1 . . . . . . |
$$ | . . X O . . . O . . 7 X O a . X O . . |
$$ | . . X O . . . . b 6 X O 2 . . X O . . |
$$ | . X O O . . . . 9 5 4 . . . . X . . . |
$$ | . X . . . . . . . 8 0 . . . . . . O . |
$$ | . . X . O X . . . . . . . . O . O . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . O X O . X . . . . . . . . . . . . |
$$ | . . . X O . . . . , . . X O O O . . . |
$$ | . . X . O . . . . . O O O X X X . . . |
$$ | . . . O . X . . . . O X X . . . . . . |
$$ | . X O . . . . . . . . . . X . . . . . |
$$ | . X . X . . . . . . . X . . . . O . . |
$$ | . . . X . . . . . O . . . . . . . . . |
$$ | . . X , O . . . . O X . . O O O . . . |
$$ | . . . X O . . O O X X . X X O X O O . |
$$ | . . . . . . . . . O X . . . X X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
The triple hane :b1: is not natural for me but it works, even if White solidly connects, White can't disconnect the two black groups. The fate of the stones :b5: and :b9: is not clear, they may be sacrificed.
Further comments
If Black cuts first, Katago's main line is the following, and is 3 points worse:
Click Here To Show Diagram Code
[go]$$Bc Black cuts first
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 6 5 . . . . . . |
$$ | . . X O . . . O . . 4 X O 3 . X O . . |
$$ | . . X O . . . . . , X O 1 . . X O . . |
$$ | . X O O . . . . . . . 2 . . . X . . . |
$$ | . X . . . . . . . . . . . . . . . O . |
$$ | . . X . O X . . . . . . . . O . O . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . O X O . X . . . . . . . . . . . . |
$$ | . . . X O . . . . , . . X O O O . . . |
$$ | . . X . O . . . . . O O O X X X . . . |
$$ | . . . O . X . . . . O X X . . . . . . |
$$ | . X O . . . . . . . . . . X . . . . . |
$$ | . X . X . . . . . . . X . . . . O . . |
$$ | . . . X . . . . . O . . . . . . . . . |
$$ | . . X , O . . . . O X . . O O O . . . |
$$ | . . . X O . . O O X X . X X O X O O . |
$$ | . . . . . . . . . O X . . . X X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Knotwilg's idea is 7 points worse than the main variation.
Click Here To Show Diagram Code
[go]$$Bc Other variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 7 3 5 . . . . . |
$$ | . . X O . . . O . 8 6 X O 4 . X O . . |
$$ | . . X O . . . . . , X O 1 9 . X O . . |
$$ | . X O O . . . . . . . 2 . . . X . . . |
$$ | . X . . . . . . . . . . . . . . . O . |
$$ | . . X . O X . . . . . . . . O . O . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . O X O . X . . . . . . . . . . . . |
$$ | . . . X O . . . . , . . X O O O . . . |
$$ | . . X . O . . . . . O O O X X X . . . |
$$ | . . . O . X . . . . O X X . . . . . . |
$$ | . X O . . . . . . . . . . X . . . . . |
$$ | . X . X . . . . . . . X . . . . O . . |
$$ | . . . X . . . . . O . . . . . . . . . |
$$ | . . X , O . . . . O X . . O O O . . . |
$$ | . . . X O . . O O X X . X X O X O O . |
$$ | . . . . . . . . . O X . . . X X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Note that Black finishes in gote.

Re: Shapes to remember (SDK level)

Posted: Thu Apr 07, 2022 9:43 am
by Knotwilg
Your main line has two 6's and 7's.
Click Here To Show Diagram Code
[go]$$Bc Katago's main line
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . 3 . 1 4 0 8 . . . |
$$ | . . X O . . . O . . . X O 5 6 X O . . |
$$ | . . X O . . . . . . X O 2 7 9 X O . . |
$$ | . X O O . . . . . . . a b d . X . . . |
$$ | . X . . . . . . . . . . c e . . . O . |
$$ | . . X . O X . . . . . . . . O . O . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . O X O . X . . . . . . . . . . . . |
$$ | . . . X O . . . . , . . X O O O . . . |
$$ | . . X . O . . . . . O O O X X X . . . |
$$ | . . . O . X . . . . O X X . . . . . . |
$$ | . X O . . . . . . . . . . X . . . . . |
$$ | . X . X . . . . . . . X . . . . O . . |
$$ | . . . X . . . . . O . . . . . . . . . |
$$ | . . X , O . . . . O X . . O O O . . . |
$$ | . . . X O . . O O X X . X X O X O O . |
$$ | . . . . . . . . . O X . . . X X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
I missed this ladder earlier.

Re: Shapes to remember (SDK level)

Posted: Thu Apr 07, 2022 10:05 am
by jlt
I corrected the diagram.

Re: Shapes to remember (SDK level)

Posted: Wed Apr 27, 2022 12:09 pm
by jlt
Position #68, Black to play. Find the next few moves.
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . . . . . . . . . . X O . . |
$$ | . . O X O X X . . . . . . . . X O . . |
$$ | . . . O O O X . . , . . . . . X O . . |
$$ | . . . . . . O X . . . . . W X O O . . |
$$ | . . O . . . O X . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Wed Apr 27, 2022 2:59 pm
by lightvector
This position feels a bit unusual, because it seems Black may have missed the typical joseki move in the upper right? Unless there is a different sequence that leads to that result.
In the joseki I know that results in a shape like the upper right, normally Black plays a hane at R18 instead of merely extending at Q18. White blocks, Black connects, then White needs to add another move to not die, which is usually at S13.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . . . . . . . . . . B B W . |
$$ | . . O X O X X . . . . . . . . X O . . |
$$ | . . . O O O X . . , . . . . . X O . . |
$$ | . . . . . . O X . . . . . . X O O . . |
$$ | . . O . . . O X . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X . W . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Although I guess it's a little uncommon regardless that white still gets to play this clamp much later, as it is common for black to add a defense here to stop the clamp.

Anyways, it may be instructive to compare and contrast how Black should handle White's clamp in the perhaps-more-standard shape, as follows:
Click Here To Show Diagram Code
[go]$$Bc Black to play here, as a contrast/complement to jlt's position
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . . . . . . . . . . X X O . |
$$ | . . O X O X X . . . . . . . . X O . . |
$$ | . . . O O O X . . , . . . . . X O . . |
$$ | . . . . . . O X . . . . . W X O O . . |
$$ | . . O . . . O X . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X . O . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Thu Apr 28, 2022 12:58 pm
by jlt
Indeed I (Black) missed the hane-connect (R18 - S18 - Q18), instead I played Q18 and White answered with R18.

In the problem position, Katago expects this
Click Here To Show Diagram Code
[go]$$Bc answer
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . 8 . . . |
$$ | . . X X X . . . . . . . . 7 6 X O . . |
$$ | . . O X O X X . . . . . . 5 4 X O . . |
$$ | . . . O O O X . . , . . . 3 2 X O . . |
$$ | . . . . . . O X . . . . 9 O X O O . . |
$$ | . . O . . . O X . . . . . . 1 X O . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
so Black sacrifices three stones and makes a strong, connected group.

Lightvector's position doesn't exist since Black has made an extra move, so I'll remove a few stones
Click Here To Show Diagram Code
[go]$$Bc other position
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . X X X . . . . . . . . 0 . X X O 4 |
$$ | . . O X O X X . . . . . 5 2 . X O . . |
$$ | . . . O O O . . . , . . . . a X O . . |
$$ | . . . . . . . . . . . . . O X O O . . |
$$ | . . O . . . . . . . . . . . 1 X O . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X 6 . |
$$ | . . . . . . . . . . . . . . . . 7 8 . |
$$ | . . . , . . . . . , . . . . . O 9 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Fri Apr 29, 2022 8:29 am
by lightvector
Yep,
It's interesting that small difference in strength of the black stones makes the difference between wanting to sacrifice them or not... but also in the variation where black got the hane, the winrate/score are only slightly better than sacrificing in the original game!

@jlt - the position I posted should exist, no? Black doesn't have an extra move.

Black got 1 stone at R18, white lost the stone at R18 but got extra stone at S18 and S13. So it's still exactly balanced in moves made by each side.

Re: Shapes to remember (SDK level)

Posted: Fri Apr 29, 2022 12:30 pm
by jlt
Oops sorry, I didn't read your preceding diagram carefully.
Interestingly, Katago expects yet another variation
Click Here To Show Diagram Code
[go]$$Bc Lightvector's position
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . . . . . . a 4 3 8 X X O . |
$$ | . . O X O X X . . . . 7 5 2 . X O . . |
$$ | . . . O O O X . . , . . 6 0 9 X O . . |
$$ | . . . . . . O X . . . . . O X O O . . |
$$ | . . O . . . O X . . . . . . 1 X O . . |
$$ | . . . . . . . . . . . . . . . X . O . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . O . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
and then Black plays a. I can't say I really understand why Black O18 is preferred in one variation and N17 in another.

Re: Shapes to remember (SDK level)

Posted: Mon May 16, 2022 2:16 am
by jlt
Position #69, another elementary shape that I missed. Not really a big mistake but an illustration of the fact that some simple moves are still missing in my brain policy network. Black to play.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . X X O . O . |
$$ | . . . X . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . X X X . . O . . |
$$ | . . X O . . . . . . . . O O O . . . . |
$$ | . X W X X . . X . . . . . . . . . . . |
$$ | X O O . X . . . . . . . . . . . . . . |
$$ | X X O O O X . O . , . . . . . , . . . |
$$ | . O . . . . O O X . . X O . . . O . . |
$$ | . O O . . O O X . X X O O O . . . . . |
$$ | . X . . O . X . X . X O O X . . . . . |
$$ | . . X X X . . . . X O X X X . O O . . |
$$ | . X O O . . . . . X O O O X . O X . . |
$$ | . . X O . O X X . , . O X O O , X . . |
$$ | . . X O . X O O X X . O X X X X . . . |
$$ | . . X X O O . . O O . O . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc this is slightly better than the solid connection
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . X X O . O . |
$$ | . . . X . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . 1 . . . . . . . . . X X X . . O . . |
$$ | . . X O . . . . . . . . O O O . . . . |
$$ | . X W X X . . X . . . . . . . . . . . |
$$ | X O O . X . . . . . . . . . . . . . . |
$$ | X X O O O X . O . , . . . . . , . . . |
$$ | . O . . . . O O X . . X O . . . O . . |
$$ | . O O . . O O X . X X O O O . . . . . |
$$ | . X . . O . X . X . X O O X . . . . . |
$$ | . . X X X . . . . X O X X X . O O . . |
$$ | . X O O . . . . . X O O O X . O X . . |
$$ | . . X O . O X X . , . O X O O , X . . |
$$ | . . X O . X O O X X . O X X X X . . . |
$$ | . . X X O O . . O O . O . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Sat May 28, 2022 2:59 am
by jlt
Position #70, Black to play a good endgame move.
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . . O , X . . O X O O O . . . X . O . |
$$ | . . X X . . X X X X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . O . . . . . . . . . . . . . |
$$ | . . . O . . O . X X X . X . . . . . . |
$$ | . O O X X . . O O O O X X O . . O . . |
$$ | . . X O X O . . . , . O X . . , . . . |
$$ | . . X . X O . X O . . O X . . O . . . |
$$ | . . . X X X X X O O O X X O . . . . . |
$$ | . . . X O O X O . . X X . . O . O . . |
$$ | . . X O . . O . O . . . . O X X O . . |
$$ | . X O O . . . . . . . . . . X O X . . |
$$ | . X X O O . . . . , . . . . . , X . . |
$$ | . X . X O . O . . O X X . . . X . . . |
$$ | . . X . . . . . O . O X . X . . . . . |
$$ | . . . . . . . . . . O O X . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Sat May 28, 2022 4:54 am
by Akura
First, my eyes were drawn to a, but then I thought that b may be good?
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . b O X O O O O X O O X X . . X X . |
$$ | . . O , X . . O X O O O . . . X . O . |
$$ | . . X X . . X X X X . . . . . . . a . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . O . . . . . . . . . . . . . |
$$ | . . . O . . O . X X X . X . . . . . . |
$$ | . O O X X . . O O O O X X O . . O . . |
$$ | . . X O X O . . . , . O X . . , . . . |
$$ | . . X . X O . X O . . O X . . O . . . |
$$ | . . . X X X X X O O O X X O . . . . . |
$$ | . . . X O O X O . . X X . . O . O . . |
$$ | . . X O . . O . O . . . . O X X O . . |
$$ | . X O O . . . . . . . . . . X O X . . |
$$ | . X X O O . . . . , . . . . . , X . . |
$$ | . X . X O . O . . O X X . . . X . . . |
$$ | . . X . . . . . O . O X . X . . . . . |
$$ | . . . . . . . . . . O O X . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Sat May 28, 2022 10:53 am
by jlt
'b' was indeed the correct move:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . 2 6 O . . O X X O X . X . . . . . |
$$ | . 3 1 O X O O O O X O O X X . . X X . |
$$ | . 5 O 4 X . . O X O O O . . . X . O . |
$$ | . . X X a . X X X X . . . . . . . . . |
$$ | . 7 . . . . . . . . . . . . . . O . . |
$$ | . . O . . O . . . . . . . . . . . . . |[/go]
White can cut later at 'a' but Black will sacrifice 2 stones and both parts will live separately.

If Black doesn't play there then later White can play 'a' below. This threatens the cut 'b' which is much more severe than in the previous diagram.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . . O , X . . O X O O O . . . X . O . |
$$ | . a X X . b X X X X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . O . . . . . . . . . . . . . |[/go]

Re: Shapes to remember (SDK level)

Posted: Sun May 29, 2022 4:03 pm
by EricBackus
What about trying to cut off the D12 white stones, by playing:
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . . O , X . . O X O O O . . . X . O . |
$$ | . . X X . . X X X X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . O . . . . . . . . . . . . . |
$$ | . . . O . 1 O . X X X . X . . . . . . |
$$ | . O O X X . . O O O O X X O . . O . . |
$$ | . . X O X O . . . , . O X . . , . . . |
$$ | . . X . X O . X O . . O X . . O . . . |
$$ | . . . X X X X X O O O X X O . . . . . |
$$ | . . . X O O X O . . X X . . O . O . . |
$$ | . . X O . . O . O . . . . O X X O . . |
$$ | . X O O . . . . . . . . . . X O X . . |
$$ | . X X O O . . . . , . . . . . , X . . |
$$ | . X . X O . O . . O X X . . . X . . . |
$$ | . . X . . . . . O . O X . X . . . . . |
$$ | . . . . . . . . . . O O X . . . . . . |
$$ ---------------------------------------[/go]
I suppose it must not work, but in my first glance at it, it looked promising...

Re: Shapes to remember (SDK level)

Posted: Sun May 29, 2022 9:52 pm
by jlt
From my kyu perspective, White would just sacrifice two stones, which is not so big:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . . O , X . . O X O O O . . . X . O . |
$$ | . . X X . . X X X X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . O 4 . . . . . . . . . . . . |
$$ | . . . O 2 1 O . X X X . X . . . . . . |
$$ | . O O X X 3 . O O O O X X O . . O . . |
$$ | . . X O X O . . . , . O X . . , . . . |
$$ | . . X . X O . X O . . O X . . O . . . |[/go]
but the AI thinks it's a wrong sequence for White because the weakness C17 is still there, so the following is a much better move
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . . . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . 4 O , X . . O X O O O . . . X . O . |
$$ | . 2 X X . . X X X X . . . . . . . . . |
$$ | 7 3 5 . 8 . . . . . . . . . . . O . . |
$$ | . 6 O . 0 O . . . . . . . . . . . . . |
$$ | . . . O 9 1 O . X X X . X . . . . . . |
$$ | . O O X X . . O O O O X X O . . O . . |
$$ | . . X O X O . . . , . O X . . , . . . |
$$ | . . X . X O . X O . . O X . . O . . . |[/go]
Black cannot cut immediately because White threatens to kill A14 so...
Click Here To Show Diagram Code
[go]$$Bcm11
$$ ---------------------------------------
$$ | . . . . . . . . . O X . X . . . . . . |
$$ | . . 2 . O . . O X X O X . X . . . . . |
$$ | . . . O X O O O O X O O X X . . X X . |
$$ | . O O 1 X . . O X O O O . . . X . O . |
$$ | . O X X . 3 X X X X . . . . . . . . . |
$$ | X X X . O . . . . . . . . . . . O . . |
$$ | . O O . O O . 4 . . . . . . . . . . . |
$$ | . . . O X X O . X X X . X . . . . . . |
$$ | . O O X X . . O O O O X X O . . O . . |
$$ | . . X O X W . . . , . O X . . , . . . |
$$ | . . X . X W . X O . . O X . . O . . . |[/go]
Now, Black could capture the two marked stones but it's not very big at the moment.
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