I have a question about a pretty famous variation in a 3-4 pincer joseki. I've given the full sequence for those not familiar with it.

It starts like this

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[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . 3 . . 2 8 1 . . |
$$ | . . . . . . . . . . . . . 6 5 . . . . |
$$ | . . . . . . . . . . . . . 0 7 . 9 . . |
$$ | . . . . . . . . . . . . . . . 4 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

And carries on like this

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[go]$$Bcm11
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . a . . . |
$$ | . . . . . . . . . . . . . . . . 2 b . |
$$ | . . . , . . . . . , . X . . O O X . . |
$$ | . . . . . . . . . . . . . O X . 3 . . |
$$ | . . . . . . . . . . . . . O X . X . . |
$$ | . . . . . . . . . . . . . . 1 O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

Generally, a is played if black has the ladder, otherwise b. Certainly b is desirable to play. Sometimes b can even be played without the ladder. Anyway, that is not really the point of this question. Let us carry on with the b line.

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[go]$$Bcm15
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 8 7 5 9 . . . |
$$ | . . . . . . . . . . . . 4 3 6 0 O O . |
$$ | . . . , . . . . . , . X 2 1 O O X . . |
$$ | . . . . . . . . . . . . . O X . X . . |
$$ | . . . . . . . . . . . . . O X . X . . |
$$ | . . . . . . . . . . . . . . X O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

Now black cuts, and the variation continues

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[go]$$Bcm25
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . 2 4 O X X X . . . |
$$ | . . . . . . . . . . 3 . O X O O O O . |
$$ | . . . , . . . . . , . X O X O O X . . |
$$ | . . . . . . . . . . . . 1 O X . X . . |
$$ | . . . . . . . . . . . . . O X . X . . |
$$ | . . . . . . . . . . . . . . X O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

The joseki more or less ends here, and issues of ladders in opposite corner arise, or black needs to make something of the either the right or top. My question is, why does white not play 26 at 27? From what I can tell, white always plays 27 at 27, regardless of the ladder situation, so I guess I'm missing some obvious move or sequence. Would be grateful for any explanation.

The sensei's page for this is at http://senseis.xmp.net/?34PointHighAppr ... ncerOgeima

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[go]$$Wcm1
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . 2 . . . . 6 . |
$$ | . . . . . . . . . . . 3 O X X X 4 5 . |
$$ | . . . . . . . . . . 1 . O X O O O O . |
$$ | . . . , . . . . . , . X O X O O X . . |
$$ | . . . . . . . . . . . . X O X . X . . |
$$ | . . . . . . . . . . . . . O X . X . . |
$$ | . . . . . . . . . . . . . . X O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

Famous joseki mistake. Black wins the capturing race.

_________________
Amsterdam, soon.

An example of: http://senseis.xmp.net/?TwoHanesGainALiberty

Playing here is "wrong" move order. You first hane above .

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[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . X . . O O X . . |
$$ | . . . . . . . . . . . . . O X . 1 . . |
$$ | . . . . . . . . . . . . . W X . X . . |
$$ | . . . . . . . . . . . . . 3 2 O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ +---------------------------------------+[/go]

Although this has been played - that's right - in a Korean game : D

_________________
My "guide" to become stronger in Go

The timing of the original below is suspect. However, the story is a little more complicated. Pushing up at at this point appears in over 300 games in GoGoD. So the problem is not obvious. first appears in GoGoD played by Japanese amateurs at the beginning of the '70's. Kim In then came up with as a reply. This variation was played a few times over the years in Korea but without clear success for Black. As a result, the connection at as a reply to has not appeared since 1990.

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[go]$$Wc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . X . . O O X . . |
$$ | . . . . . . . . . . . . . O X . 2 . . |
$$ | . . . . . . . . . . . . . 1 X . X . . |
$$ | . . . . . . . . . . . . . 4 3 O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |[/go]

The more thematic issue is the reply of to below (the "normal" choice of ). Note that White can not continue with a play at 4 because has taken away a liberty, making the cut at 'e' more threatening. So White goes back and connects at . Play normally proceeds up to . Black has gained in the upper right corner while fixes White's cutting point and does a better job of undercutting the top. So why doesn't Black do this all the time? One point is that in the future White looks for the opportunity to descend at 'a' which Black can't resist too strongly because of the weakness in the shape here. So this variation is rare in the main line. However, if White first exchanges 'b' for 'c' before playing , it is much easier for Black to descend at because the marked White stone has been significantly weakened by the addition of a Black stone at 'c'. All that said, however, in most modern games in GoGoD Black just goes ahead and connects at 'd' anyway without attempting anything tricky. Black seems satisfied with reverting to the normal order of events.

Click Here To Show Diagram Code

[go]$$Wc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 5 . . |
$$ | . . . . . . . . . . . . . 3 . . 1 4 . |
$$ | . . . , . . . . . , . X . e O O X 2 . |
$$ | . . . . . . . . . . . . . O X . d . . |
$$ | . . . . . . . . . . . . . b X . X . . |
$$ | . . . . . . . . . . . . . . c W a . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |[/go]

_________________
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21

Thanks for the clarification! I got my information from the Sensei's page.

(Luckily I get my Joseki book back today ^^)

_________________
My "guide" to become stronger in Go

Here's a game of a friend of mine where he got tricked by a move which ends up also leading to the 2 hanes gain an extra liberty shape (but there was a long ko left and he still won ).