I feel like black is missing something big here by allowing white to so easily strengthen his group.
$$Wcm24 What I would play
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$$ | . . . . . O . . . . . . . O . O O O . |
$$ | . . . O . . . . . , . . . . X X X O . |
$$ | . . . . . . . . . . . . a . . . X X . |
$$ | . . X . . . . . . . . . . . . . O . . |
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$$ | . . . . . . . . . . . . . . . . X . . |
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$$ | . . . X . . . . . , . . . . . , . . . |
$$ | . 4 2 . . . . . . . . . . . . . . . . |
$$ | . . 1 3 . z . . . . . . . e d . b . . |
$$ | . . . . . y . . . . . . . . . . . . . |
$$ | . . . . . . x . . . . . . . . O . . . |
$$ | . . O . 5 . . . . . . . . . . . . . . |
$$ | . . . , . . 6 . . , . X . . . , O . . |
$$ | . . X . X . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . c . . |
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- Click Here To Show Diagram Code
[go]$$Wcm24 What I would play
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$$ | . . . . . O . . . . . . . O . O O O . |
$$ | . . . O . . . . . , . . . . X X X O . |
$$ | . . . . . . . . . . . . a . . . X X . |
$$ | . . X . . . . . . . . . . . . . O . . |
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$$ | . . . . . . . . . . . . . . . . X . . |
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$$ | . . . X . . . . . , . . . . . , . . . |
$$ | . 4 2 . . . . . . . . . . . . . . . . |
$$ | . . 1 3 . z . . . . . . . e d . b . . |
$$ | . . . . . y . . . . . . . . . . . . . |
$$ | . . . . . . x . . . . . . . . O . . . |
$$ | . . O . 5 . . . . . . . . . . . . . . |
$$ | . . . , . . 6 . . , . X . . . , O . . |
$$ | . . X . X . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . c . . |
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This still expands the bottom of the board. It is not as large as the potential black is shooting for, but I think black has big problems with the sequence he plans.
The white group on the left and the right are both not alive locally and black takes good profit on the bottom while strengthening his group on the top left. Without another move by white black can start to surround the white group and attack it very hashly with moves like 'x', 'y', or 'z'. If white chooses to defend then there are lots of great points for black to take, like 'a' to threaten to seal in the corner and reduce the top. If white responds to 'a' then 'b' and 'c' are a sort of miai for the security of white's group. If black grabs 'b' then white has to make a base at 'c' allowing black to expand his framework with moves like 'd' and 'e'.
And if white decides not to make his base in the corner then black has the dream of every go player: Two weak groups to attack within his influence.
$$Wcm24 How black wants to play
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$$ | . . . . . O . . . . . . . O . O O O . |
$$ | . a . O . . . . . , . . . . X X X O . |
$$ | . . . . . . . . . . . . . . . . X X . |
$$ | . . B . . . . . . . . . . . . . O . . |
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$$ | . . . . . . . . . . . . . . . . X . . |
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$$ | . . . B . . . . . , . . . . . , . . . |
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$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . O O X X . . . . . . . . . O . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . X . . . , O . . |
$$ | . . X . X . . . . . . . . . X . . . . |
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$$ | . . . . . . . . . . . . . . . . . . . |
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- Click Here To Show Diagram Code
[go]$$Wcm24 How black wants to play
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$$ | . . . . . O . . . . . . . O . O O O . |
$$ | . a . O . . . . . , . . . . X X X O . |
$$ | . . . . . . . . . . . . . . . . X X . |
$$ | . . B . . . . . . . . . . . . . O . . |
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$$ | . . . . . . . . . . . . . . . . X . . |
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$$ | . . . B . . . . . , . . . . . , . . . |
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$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . O O X X . . . . . . . . . O . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . X . . . , O . . |
$$ | . . X . X . . . . . . . . . X . . . . |
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This definitely builds the bottom in a big way. The spacing of the stones seems about right and there is no doubt that black will get something big on the bottom. However, look at the whole board. What has happened to the two black stones in the top left? The star point stone is now only one point away from white thickness and the other is three spaces from it. A move by white at 'a' secures corner territory while now threatening to severely attack the two stones. After this I'd feel very unsure as black. How do I help my two stones? Sure, the aji of the 6-3 stone can be used for a 3-3 invasion reduction, but after that what will become of the two stones on the outside? And if I surrender them then white got to take fifth line territory on the left as I grabbed a seventh line framework on the bottom. So black will need to run. And as he runs white will build the top side, reduce the bottom side, or, quite likely, both.
The bottom is not territory. It is only a moyo. If white wanted to he could invade and live on the bottom. The black stones on the right are very thin. There is a lot of aji, but to do that immediately would of course be too soon. As black sealed white in his outside potential would be enormous and white's two stones on the right would cry in agony at the growing thickness of black's wall. But it is still not territory, even if white won't reduce or invade immediately.
I feel like black is allowing white to live here quite easily when he could have made it difficult.