Life In 19x19

I think this is bigger than extending from the wall on the right, and that group shouldn't be in any danger yet.

Black's move feels inefficient or otherwise lacking in some respect to me, but I can't quite put my finger on why.

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[go]$$Bcm71 Prisoners: White stones:0 ; Black stones:2
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . d 1 . a . b . . . |
$$ | . . . , . . . . . O . . . . . X . . . |
$$ | . . O . . . . . . . . c . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . e . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . , . . . . . , . . . |
$$ | . . O X . X . . . . . . X O . . . . . |
$$ | . . O O . . . . M . . . O . O O O . . |
$$ | . . . . . O . . . . . . . O X X O O . |
$$ | . . . . . . . . . . X . X X X O O X . |
$$ | . . O . . . . . . . . X O . X O X X . |
$$ | . . . , O O O . . , X O O . X O X . . |
$$ | . . X . X X X . . . X X O O O X X . . |
$$ | . . . . . . . . . . X O . O . O X . . |
$$ | . . . . . . . . . X O O . . O . . . . |
$$ ---------------------------------------[/go]

A through E are some moves I am looking at. I'd also like to get a move in at the marked point at some time in the near future. I will post sequences later.

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

I want to make the attach-extend shape here, as I can still invade the corner for at least a ko, I believe. If black takes gote to defend, white claims the top left in one move.

As for the previous post... D and E both feel kyuish, to say the least. Defending something one doesn't have. A and B seem premature, and I can't think of a good followup for C.

Okay, I have thought long and hard about the different options, an outside hane and nobi, here.

The hane will give me more territory, but invite the crosscut. I do not fear the fight that could come, what I fear is that he will sacrifice the cross-cutting stone to make shape in sente.

The nobi is solid, and I still undercut white's position on the top.

I chose the nobi because I don't want him to make shape here in sente. The wall he can get by leaning is misplaced, my group on the middle left will diminish it's influence. I extend to the left instead of to the right to deny him perfect shape.

I've got to block at some point... Not sure what my opponent will do though.

Since I have sente and the position is relatively stable, it is time to evaluate the position.

Weak groups:
There are no real weak groups on the board.
The aji at K2 is very annoying however, and my lower left corner could become weak if he plays a move in the corner and I don't go back and fix.

Bank:
If we're talking about cash, white's upper left is worth about 35 points if he plays one more move there. His lower left is about 20 points and his influence on the right can make 20 points easily. Let's say he has about 75 points.

I have 15 points on the lower left, 8 points on the lower right. Furthermore my top right is worth about 30 points. My left is worth about 10 points. Let's say I have 60 points.

This means I am behind by about ten points.

The last moves:

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[go]$$Bcm61 Prisoners: White stones:0 ; Black stones:2
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 8 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . 0 . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 9 . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 X . . . . . , . . . . . , . . . |
$$ | . . O 1 . 5 . . . . . . X O . . . . . |
$$ | . . 2 4 . . . . . . . . O . O O O . . |
$$ | . . . . . 6 . . . . . . . O X X O O . |
$$ | . . . . . . . . . . X . X X X O O X . |
$$ | . . O . . . . . . . . X O . X O X X . |
$$ | . . . , O O O . . , X O O . X O X . . |
$$ | . . X . X X X . . . X X O O O X X . . |
$$ | . . . . . . . . . . X O . O . O X . . |
$$ | . . . . . . . . . X O O . . O . . . . |
$$ ---------------------------------------[/go]

I was not so unhappy with the 61-67 exchange. I think his lower left is overconcentrated. My left group is almost as powerful as his left group. Maybe my 69 should have been around 70, because it is a perfect point for him. However, a play of him at 69 would also be very big, so this exchange seems even. Moves 71 to 76 definately favor me. His wall is not facing towards a potentially weak group, nor will it be easy for him to make center territory. However I am not sure what I would have played as 72 for white.

Potentially harmful or joyful points

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[go]$$Bcm71 Prisoners: White stones:0 ; Black stones:2
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . d . . . 6 3 1 5 . . . . . . |
$$ | . . . , . . . . . O 4 2 . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . 7 . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . c . . |
$$ | . . . . . . . . . . . . . . . . c . . |
$$ | . . X X . . . . . , . . . . . , . . . |
$$ | . . O X . X . . . . . . X O . . . . . |
$$ | . . O O . . . . . . . . O . O O O . . |
$$ | . . . . . O . . . . . . . O X X O O . |
$$ | . . . . . . . . . . X . X X X O O X . |
$$ | . a O . . . . . . . . X O . X O X X . |
$$ | . . . , O O O . . , X O O . X O X . . |
$$ | . a X . X X X . . . X X O O O X X . . |
$$ | . . . . . . . . . b X O . O . O X . . |
$$ | . . . . . . . . . X O O . . O . . . . |
$$ ---------------------------------------[/go]

If I maintain sente, I would like to play at a to take some corner points and make sure my corner and middle group are absolutely safe. After that I can play freely with no concern.

I'm not sure white is overconcentrated in the lower left as stated Deflow. Overconcentrated is when there are stones who are inefficient and could be removed or moved elsewhere to have more impact on the game. I don't see any such stone in white's shape, each seems to be necessary or useful.

Also i'm doubtful about white's moves in the top, Black 77 seems far too good to have ever been allowed. Shouldn't white attack the lower black group before settling the border with the top right ?