Pseudo sente, superficial shape, reading and other mistakes

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Farodin
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Re: Pseudo sente, superficial shape, reading and other mista

Post by Farodin »

Click Here To Show Diagram Code
[go]$$Wc Katago recommendation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | 2 1 . . . . O O X . . . . X O O X O . |
$$ | . X O O . . O X . . X . . X . X O . . |
$$ | . . X , O . X X . , . . . X . , O . . |
$$ | . X . . . . . . 3 6 . . . . . O . . . |
$$ | . . X O O O . 5 4 . . . . . . . X O . |
$$ | . . . X X O . O . X . . . . X . X O . |
$$ | . . . . . . . . O . . . . . . . X 7 . |
$$ | . X . . X . X . . . . . . . O . . . . |
$$ | . . X , . . . . . , . . . . . , X . . |
$$ | X X O X . . . . . . . . . . . O X . . |
$$ | O O O X . . . . . . . . . . . O O X . |
$$ | O X X X O . . . . . . . . . . . . X . |
$$ | O O X X . . . . . . . . . . . . O O . |
$$ | O O O X . O O . . . . . . . . . . . . |
$$ | . . . O . X O X X , . O . . . O . . . |
$$ | . . O . O O X X O . X X X . . O . . . |
$$ | . . . . . . . . . . . . . . X X O O . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ ---------------------------------------[/go]
What exactly is the purpose of all those exchanges before move 7? I have seen it happen a lot in pro games as well, but I find it hard to understand them. My guess for the 1-2 exchange is that a black follow-up at C18 is easier to deal with, but I don't exactly see why. Not to speak of the 3-6 exchange, which is entirely beyond me.
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Re: Pseudo sente, superficial shape, reading and other mista

Post by Knotwilg »

Farodin wrote: What exactly is the purpose of all those exchanges before move 7? I have seen it happen a lot in pro games as well, but I find it hard to understand them. My guess for the 1-2 exchange is that a black follow-up at C18 is easier to deal with, but I don't exactly see why. Not to speak of the 3-6 exchange, which is entirely beyond me.
This is a question of a whole other level (pro/AI). I looked at what would happen if White plays 7 directly. The 1-2 exchange remains forcing but the 3-6 exchange would no longer occur in that case, as Black will deal with 3 differently. Analyzing that is beyond me. Let's say that my main mistake is playing my move instead of 7.
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Re: Pseudo sente, superficial shape, reading and other mista

Post by Uberdude »

1 for 2 is not so mysterious, it makes black only have a gote move followup in that area with c18, rather than the choice of b18 or c18. b18 might be preferred if its sente profit against the life of the white group. You sometimes see this hane in endgames to prevent your opponent making sente profit and reduce their option to gote, it can help with tedomari. I remember Vanessa Wong 5d ruing her failure to make a similar hane (on edge not corner) and thus losing in endgame against Osawa Maya (one of the top Japanese amateur women, sister Narumi is pro) in the women's semi-final at the World Mind Sports Games 2012 in Lille.

3-6 aren't a standard idea, but seem to be looking at the the j17 cut, and in the process of defending that white makes some options for eyes at g12.
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