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Corner from game

Posted: Fri Aug 07, 2015 9:26 am
by emeraldemon
What should white have done here?

Click Here To Show Diagram Code
[go]$$Bcm1 White to play
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | . . O X X O . . O . . . . . . . O O O |
$$ | . . O X X O . . . , . . . O . O . . . |
$$ | . . O O X X X . O . . O . . . . . . . |
$$ | . . . . O O X . . . . . . . . . . . . |
$$ | . . . . . 1 . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In the game white lost the corner and resigned:

Click Here To Show Diagram Code
[go]$$B Moves 155 to 164
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | . 3 O X X O . . O . . . . . . . O O O |
$$ | . 4 O X X O . . . , . . . O . O . . . |
$$ | . 0 O O X X X . O . . O . . . . . . . |
$$ | 8 5 . 2 O O X . . . . . . . . . . . . |
$$ | . 9 6 . 7 1 . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


White 4 @ 5 easily lives, but I'm sure white wanted the most points possible.

Click Here To Show Diagram Code
[go]$$Bcm1 Alive
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | . 3 O X X O . . O . . . . . . . O O O |
$$ | . . O X X O . . . , . . . O . O . . . |
$$ | . . O O X X X . O . . O . . . . . . . |
$$ | . 4 . 2 O O X . . . . . . . . . . . . |
$$ | . . . . . 1 . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


It looks like playing the hane instead of solid connect might work, but maybe there's an attack I'm missing:

Click Here To Show Diagram Code
[go]$$Bcm1 White to play
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | . 3 O X X O . . O . . . . . . . O O O |
$$ | . 4 O X X O . . . , . . . O . O . . . |
$$ | . . O O X X X . O . . O . . . . . . . |
$$ | . 5 6 . O O X . . . . . . . . . . . . |
$$ | . 8 . 2 . 1 7 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This way black captures 2 stones, so maybe it's actually worse?

Re: Corner from game

Posted: Sat Aug 08, 2015 1:55 pm
by Loons
Can you quickly show why :w8: cannot be D1 in your last diagram?

Re: Corner from game

Posted: Sat Aug 08, 2015 2:13 pm
by DrStraw
Loons wrote:Can you quickly show why :w8: cannot be D1 in your last diagram?


Mainly because D1 is occupied. If you meant E1 then :

Click Here To Show Diagram Code
[go]$$Bcm1 White to play
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | 7 X O X X O . . O . . . . . . . O O O |
$$ | 6 O O X X O . . . , . . . O . O . . . |
$$ | 5 . O O X X X . O . . O . . . . . . . |
$$ | . X O . O O X . . . . . . . . . . . . |
$$ | . 3 4 O 2 X 1 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Corner from game

Posted: Sat Aug 08, 2015 2:18 pm
by Loons
Oh, yes, that potential ko is a picnic for black.

Edit: However, white took sente against living with points in DrStraw's diagram. Versus... Living in gote with ~3 points in emeraldemon's second diagram.

Emeraldemon's last diagram is slightly harder for me to count. White has... Five points in gote?

Edit edit : Which is to say, DrStraw's position ends leaving a 4 point gote after white's implicit last move. Eight. I should really count in a consistent and comparable way. Is it actually worth 2 points for white?

Re: Corner from game

Posted: Sat Aug 08, 2015 3:07 pm
by emeraldemon
Now I'm more confused. Isn't the line in DrStraw's diagram seki? Is there a ko I'm missing?

Re: Corner from game

Posted: Sat Aug 08, 2015 3:43 pm
by DrStraw
emeraldemon wrote:Now I'm more confused. Isn't the line in DrStraw's diagram seki? Is there a ko I'm missing?


Yes, it is seki.

Re: Corner from game

Posted: Sat Aug 08, 2015 7:05 pm
by Loons
Click Here To Show Diagram Code
[go]$$Bcm1 White to play
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | X X O X X O . . O . . . . . . . O O O |
$$ | O O O X X O . . . , . . . O . O . . . |
$$ | X . O O X X X . O . . O . . . . . . . |
$$ | . X O . O O X . . . . . . . . . . . . |
$$ | . X O O O X X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Did I turn into a DDK? Bottom left is unsettled.

Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | X X O X X O . . O . . . . . . . O O O |
$$ | O O O X X O . . . , . . . O . O . . . |
$$ | X . O O X X X . O . . O . . . . . . . |
$$ | 1 X O . O O X . . . . . . . . . . . . |
$$ | . X O O O X X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
White has lived in gote, and there are eight points in gote at stake.

Click Here To Show Diagram Code
[go]$$Bcm1
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | 7 . X . X O . O O . . . . . X . X X O |
$$ | 6 X O X X O . . O . . . . . . . O O O |
$$ | . O O X X O . . . , . . . O . O . . . |
$$ | 5 . O O X X X . O . . O . . . . . . . |
$$ | . X O . O O X . . . . . . . . . . . . |
$$ | . 3 4 O 2 X 1 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Picnic (ish) ko for black. White would have needed an unremoveable ko threat.

Re: Corner from game

Posted: Sat Aug 08, 2015 7:11 pm
by DrStraw
I assumed that W would play as in your second diagram and B would capture, giving seki. In the third diagram B just connects with 7 and it reverts.

Re: Corner from game

Posted: Sat Aug 08, 2015 7:17 pm
by Loons
Oh, yes, sorry, the implicit :w8: and :b9: made it slightly unclear to me, also because :b9: was gote it shouldn't be implicitly played? What does 7... connect revert to? Wait, I will make some coffee, and hopefully begin reading sensibly.

Re: Corner from game

Posted: Sat Aug 08, 2015 7:27 pm
by Loons
Click Here To Show Diagram Code
[go]$$Bcm1
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | 9 7 X . X O . O O . . . . . X . X X O |
$$ | 6 X O X X O . . O . . . . . . . O O O |
$$ | . O O X X O . . . , . . . O . O . . . |
$$ | 5 8 O O X X X . O . . O . . . . . . . |
$$ | 0 X O . O O X . . . . . . . . . . . . |
$$ | . 3 4 O 2 X 1 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
White has lived in gote with ... what, 6 points? But black would not play this way.

Using some consistent kind of counting, Emeraldemon's last diagram was worth 2 1/2 points, and the solid connect turned out to be worth 2 points, where solidly connecting was worth 1 1/2 (just over) points. Possibly I need to go back and read DrStraw on this because I feel like I am that crazy person rambling.

Re: Corner from game

Posted: Sat Aug 08, 2015 8:07 pm
by DrStraw
Loons wrote:
Click Here To Show Diagram Code
[go]$$Bcm1
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | 9 7 X . X O . O O . . . . . X . X X O |
$$ | 6 X O X X O . . O . . . . . . . O O O |
$$ | . O O X X O . . . , . . . O . O . . . |
$$ | 5 8 O O X X X . O . . O . . . . . . . |
$$ | 0 X O . O O X . . . . . . . . . . . . |
$$ | . 3 4 O 2 X 1 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
White has lived in gote with ... what, 6 points? But black would not play this way.

Using some consistent kind of counting, Emeraldemon's last diagram was worth 2 1/2 points, and the solid connect turned out to be worth 2 points, where solidly connecting was worth 1 1/2 (just over) points. Possibly I need to go back and read DrStraw on this because I feel like I am that crazy person rambling.


You are right. I answered quickly and did not think about :w8:

Re: Corner from game

Posted: Sun Aug 09, 2015 1:08 pm
by emeraldemon
Thanks for looking at this. It sounds like since the seki doesn't work, protecting with the hane makes the white group live with points?

Click Here To Show Diagram Code
[go]$$Bcm1 White saves the corner
$$ ---------------------------------------
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . X . X O . . O X . . . . . . . O O . |
$$ | . . . X O . . O X . . X . . O . O . O |
$$ | . . . , . O . O X , . . X X O O X O . |
$$ | . . X . . . O X . . O X . . O X X X . |
$$ | . . X O O O X X . . X O O X O O O X . |
$$ | . X . . . X . . . X . X O O O . O X . |
$$ | . . O O O X . . . . X X X X . O X O . |
$$ | . . O X X . . . . X O O O . O . X . . |
$$ | . O X X . . X . . , X . O . O X X . . |
$$ | . O O X . X O X X . X O . . X . . . . |
$$ | . O X . . O . O O X X O . . . . . X . |
$$ | . X . X . . O . . O O X X . . . . . X |
$$ | . . X . X O . O O . . . . . X . X X O |
$$ | . 3 O X X O . . O . . . . . . . O O O |
$$ | . 4 O X X O . . . , . . . O . O . . . |
$$ | . . O O X X X . O . . O . . . . . . . |
$$ | . . . . O O X . . . . . . . . . . . . |
$$ | . . . 2 . 1 7 . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


I thought this was a relatively straightforward position, but it seems complicated to me now.