Life In 19x19

Chew Terr wrote:I was originally going to hane underneath, but then I got greedy. Given my stone at

Click Here To Show Diagram Code

[go]$$Wm11
$$ ---------------
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . . . . O .
$$ | . . . X . . .
$$ | . . . . . . .
$$ | . . . X . . .
$$ | . . . O 8 . .
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . X , . . .
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . . . . # .
$$ | . . . X . . .[/go]

Chew Terr's outside hane and his reasoning about are right on the money.

However, in his variation, his atari is a common misunderstanding:

Click Here To Show Diagram Code

[go]$$B
$$ ---------------
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . . . . O .
$$ | . . . X . . .
$$ | . . . . 3 . .
$$ | . . . X 2 4 .
$$ | . . . O 1 . .
$$ | . . . . . . .[/go]

The correct atari for B is the other way (same as in my #103 game with topazg):

Click Here To Show Diagram Code

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

Where for Joaz if you had simply nobi-d upwards ? I'm sure I've been told that when strong locally, extending from attachments is often good.

(NB I am not really endorsing anything here, just curious)

Loons wrote:Where for Joaz if you had simply nobi-d upwards ? I'm sure I've been told that when strong locally, extending from attachments is often good.

Yes, Ishida also mentioned the nobi up when B is strong locally.

Is black not strong locally ?

Loons wrote:Is black not strong locally ?

I think B is quite strong locally.

That reply is by far the most aggressive.
Most people either choose this:

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . B W . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |[/go]

...in which black concedes running room to white while taking sure but modest territory. The reducing stones are always a concern for white, and he usually spends a move to connect them to something midway through the game.

The solidly aggressive extension is sometimes played:

Click Here To Show Diagram Code

[go]$$Wcm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . a . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . b b . . . . . . . . . . . . . . . . |
$$ | . . b X B . . . . . . . . . . . X . . |
$$ | . . . W . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |[/go]

...in which black concedes both some eastward running room to white, and some westward invasion, in return for a solid position. Black always takes 'a' and usually something around 'b'.

But the upper hane is notable in that it blocks both an immediate run eastward, and any play underneath. The former is obvious. The latter looks like this:

Click Here To Show Diagram Code

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

...in which black has solid territory and white has zilch.

So at this point, I'm outside my comfort zone and relying on a very fuzzy memory. White has several options:
1) The outside wall
2) The ko
3) tenuki

The outside wall looks like this: ( as noted before, it is good to have the favorable ladder - shown here with the blue arrow. )

Click Here To Show Diagram Code

[go]$$Wcm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X 7 . . . . , . . . . . X . . . |
$$ | . . . 4 3 . . . . . . . . . . . . . . |
$$ | . . . X 1 2 . . . . . . . . . . X . . |
$$ | . . . W X 5 . . . . . . . . . . . . . |
$$ | . . . . 6 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ { AR G13 K10 }[/go]

Or the outside wall looks like this:

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . a . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . 2 7 . . . . . . . . . . . . . |
$$ | . . . X 1 3 . . . . . . . . . . X . . |
$$ | . . . W X 5 . . . . . . . . . . . . . |
$$ | . . . 4 6 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |[/go]

The important thing for me is to be able to suppress the moyo and not have to come back an d protect 'a' in certain gote. To that extent, both of the previous diagrams work for me. Whether I end in gote or not is not clear, as getting to the corner is big.

The ko looks like this:

Click Here To Show Diagram Code

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

It is not at all clear who does better in a ko.

My current preferrence is for the wall. I have to think about it a bit more.

Click Here To Show Diagram Code

[go]$$Wcm11
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X 8 . . . . . . . . . . . X . . |
$$ | . . . W . . . . . . . . . . . . . . . |
$$ | . . . . . a . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I feel like he would have done some of that light dodgy business if I gave him more space to. He might, still, but it seems harder on the board this way. This is kind of hard to respond to (the best I seem to have is 'a', because against many moves, black can just sacrifice one stone and jump out with the other for a successful reduction.

If you atari my last move, I extend.

Click Here To Show Diagram Code

[go]$$Bcm20
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . 1 . . . . . . . . . . . . . . |
$$ | . . 5 X O 2 . . . . . . . . . . X . . |
$$ | . . 4 O X . . . . . . . . . . . . . . |
$$ | . . . 3 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code

[go]$$Bcm20
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . O . . . O . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . 1 . . . . . . . . . . . . . . |
$$ | . . 5 X O 2 . . . . . . . . . . X . . |
$$ | . . 4 O X 7 . . . . . . . . . . . . . |
$$ | . . 8 3 6 . . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

The only question in my mind, really, was whether 24 should be above or below the two stones. If this is safe, this seems best, as it doesn't grant the atari and the aji that comes with. As I can't seem to read anything too bad, I'm going with this. White could play more aggressively to break into my left side, by forcing me to capture 23, but his resulting stones will all be weak and potentially heavy. I feel like I can be content with this unless I'm missing something huge.

Since B is strong locally, the atari is OK, but the other way (B atari at instead) is still better:
see also and here: www.lifein19x19.com/forum/viewtopic.php ... 3&start=80

Because W can do better than Chew's variation --
W can close B and now the aji in this corner is not good for B:

Click Here To Show Diagram Code

[go]$$B
$$ -----------------------
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . O . . . O .
$$ | . . . X . . . . . , .
$$ | . . . . 1 8 . . . . .
$$ | . . 5 X O 2 . . . . .
$$ | . . 4 O X . . . . . .
$$ | . . 6 3 . . . . . . .
$$ | . . . 7 . . . . . . .
$$ | . . X , . . . . . , .
$$ | . . . . . . . . . . .[/go]

Compare:

Click Here To Show Diagram Code

[go]$$B
$$ ---------------
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . . . . O .
$$ | . . . X . . .
$$ | . . . 3 2 . .
$$ | . . . X O 1 .
$$ | . . . O X . .
$$ | . . . . . . .[/go]

No, I have no pretentions of living down there. But the aji is well worth it.

More later...

To put things in perspective: remember that a few moves back I was faced with a burgeoning black left side, and a my own thinness up top. To remedy both of those problems simultaneously, I threatened to invade the left, assuming that I could either get an invasion or an outside wall. MHO made the most aggressive possible reply, denying any chance of an invasion, so I'm going for the wall. Its approximate future location is indicated by the triangles.
Not only does a wall hold him back on the left, but I don't have to make small gote moves up top, for once the wall is in place, the two circled stones are no longer thin, but function as extensions off of the wall.

Click Here To Show Diagram Code

[go]$$Bcm20
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . W . . . W . . . . . |
$$ | . . . X . T . . . , . . . . . X . . . |
$$ | . . . . X T . . . . . . . . . . . . . |
$$ | . . X X O O . . . . . . . . . . X . . |
$$ | . . O O X T . . . . . . . . . . . . . |
$$ | . . O X . T . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

So the issue for me is how to construct that wall.

Note to beginners:

The immediate threat, of course is the double atari at 'a', and the escape at 'b'. Not surprisingly, those are his two best options.

Note to beginners:

Click Here To Show Diagram Code

[go]$$Bcm20
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . W . . . W . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | . . X X O O . . . . . . . . . . X . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . O X a . . . . . . . . . . . . . . |
$$ | . . . b . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Let's look at one possible black response:

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . W . . . W . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . X 4 . . . . . . . . . . . . . |
$$ | . . X X O O . . . . . . . . . . X . . |
$$ | . . O O X 2 . . . . . . . . . . . . . |
$$ | . . O X 3 . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White 4 starts to assemble the pieces of wall, and is more aggresive than it looks.
Because of the aji of the three sacrifice stones, taking the corner is big:

Click Here To Show Diagram Code

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

( BTW, note how bulky and clumpy the black stones are becoming )

One possible continuation is like this:

Click Here To Show Diagram Code

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

Another is like this:

Click Here To Show Diagram Code

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

Note to beginners:

My current guess at black's best(?) result is this:

Click Here To Show Diagram Code

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

It is all sente for white. And black will still have to fill one more point of his territory in gote sometime in yose.

----

That was one black response. Let's look at the other:

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . W . . . W . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | . . X X O O . . . . . . . . . . X . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . O X 1 4 . . . . . . . . . . . . . |
$$ | . . 3 2 . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White 2 threatns to run, so 3 is forced. White 4 is sente.

Note to beginners:

Wite 6 threatens the previously shown mischief in the corner; 7 defends; 8 reinstates the threat.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 7 O . . . W . . . W . . . . . |
$$ | . . . X . 8 . . . , . . . . . X . . . |
$$ | . . . . X 6 . . . . . . . . . . . . . |
$$ | . . X X O O . . . . . . . . . . X . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . O X 1 4 . . . . . . . . . . . . . |
$$ | . . 3 2 5 . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . X . . . . . , . . . . O , . . . |
$$ | . . . . . O . . . O . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code

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

Note to beginners:

How consistent is the 2.5-3 pts per stone rule? I had heard that, but I assumed it applied to walls on the 3rd or 4th line. A wall on the 6th line must be worth less, right?

I'm also curious as to how you would work things like extensions into that. Presumably a wall that already has a good extension, or that completes a moyo, is worth more, but do you have any sense of how much more?

Unfortunately, both players do not realize the problem started with the atari.
In fact, much of the analysis in Post #88 shows the issues stemming from it.
IMO, the evaluation of the situation should start with this sequence instead
(and it'd be nice for beginners to be aware of the differences between the two ataris) --

Click Here To Show Diagram Code

[go]$$B
$$ ---------------
$$ | . . . . . . .
$$ | . . . . . . .
$$ | . . . . . O .
$$ | . . . X . . .
$$ | . . . 3 2 . .
$$ | . . . X O 1 .
$$ | . . . O X . .
$$ | . . . . . . .[/go]