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Re: Can this deviation from joseki be penalized?

Posted: Thu Jan 02, 2014 9:44 pm
by Kirby
I found some commentary on one of the 2013 Samsung Cup games between Lee Sedol and Tang Weixing.

In particular, this opening position was discussed:

Click Here To Show Diagram Code
[go]$$c
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . 8 , . . . . . , . . . . . 1 . . . |
$$ | . . 6 5 . . . . . . . . . . . . . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 0 9 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , 3 . . |
$$ | . . . 4 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$cm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . 4 . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . d X 3 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . a . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . b . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . c 1 5 . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . 2 , . . . . . , . . . . . , X . . |
$$ | . . . O . 6 . . . . . . . . 8 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
The article indicated that this progression is somewhat popular, but there are pros with different opinions. Notably, apparently, Go Seigen pointed out that there are reductions from the center around A and B, and also endgame around C and D, so taking these into consideration, black on the left is not great.

In contrast, it says that Lee Sedol had reason for playing this way:
* Black played one less stone than white on the left, so he thought that it didn't have bad efficiency for black
* The shape had thickness

White has 30 points of solid territory and sente, on the other hand.

In the game, Lee Sedol lost, though, I suppose from this commentary, we can see that there are pros with varying opinions on the value of opening positions.

This is somewhat reassuring to me, since I am sometimes confused about what's best.

Re: Can this deviation from joseki be penalized?

Posted: Thu Jan 02, 2014 10:46 pm
by Bill Spight
Kirby wrote:I found some commentary on one of the 2013 Samsung Cup games between Lee Sedol and Tang Weixing.

In particular, this opening position was discussed:

Click Here To Show Diagram Code
[go]$$c
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . 8 , . . . . . , . . . . . 1 . . . |
$$ | . . 6 5 . . . . . . . . . . . . . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 0 9 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , 3 . . |
$$ | . . . 4 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$cm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . 4 . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . d X 3 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . a . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . b . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . c 1 5 . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . 2 , . . . . . , . . . . . , X . . |
$$ | . . . O . 6 . . . . . . . . 8 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
The article indicated that this progression is somewhat popular, but there are pros with different opinions. Notably, apparently, Go Seigen pointed out that there are reductions from the center around A and B, and also endgame around C and D, so taking these into consideration, black on the left is not great.

In contrast, it says that Lee Sedol had reason for playing this way:
* Black played one less stone than white on the left, so he thought that it didn't have bad efficiency for black
* The shape had thickness

White has 30 points of solid territory and sente, on the other hand.

In the game, Lee Sedol lost, though, I suppose from this commentary, we can see that there are pros with varying opinions on the value of opening positions.

This is somewhat reassuring to me, since I am sometimes confused about what's best.
I agree with Lee Sedol about efficiency. And I am not sure that Go Seigen disagrees about that point.
Click Here To Show Diagram Code
[go]$$cm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . 0 . . . . . |
$$ | . . O , 8 . . . . , . . . . . X . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . X 7 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . , . . . . . , 4 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 5 . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . 2 , . . . . . , . . . . . , X . . |
$$ | . . . O . 6 . . . . . . . . 3 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Besides, if Black plays :b13: instead, then White has :w14:. After that, can Black do better than to revert to the left side?

Slightly OT, since Lee Sedol's play was popular, would Ootakamoku's site say that :b13: in this diagram is WRONG?