This 'n' that

Kirby · Post by **Kirby** » Mon Feb 22, 2016 10:16 am

One thing that I have observed in the past year or so is that "rules" don't apply all of the time, especially when weak groups are involved.

From an empty board, black's play might seem odd:

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . 6 . . . . . 4 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 8 . . . . . , . . . . . 0 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . 9 . . . . . . . . . . . | $$ | . . . . . 7 . . . . . . . . . . . . . | $$ | . . . 1 . . . . . , . . . . . 3 . . . | $$ | . . . . . . . . . 5 . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Moves

and

, above, seem to be "floating". For example, it's not even clear to me that the territory is solid, as there seems to be aji in black's position:

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . X . . . . . . . . . . . | $$ | . . . . . X . . . . . . . . . . . . . | $$ | . . . X . . . . W , . . . . . X . . . | $$ | . . . . . . . . . X . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

If black wanted to secure territory in this area, the "floating stones" would make more sense if they were lower:

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . X . X . , . . . . . X . . . | $$ | . . . . . . . . . X . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Now the position is much more clear.

But in the game, there is a weak group involved:

Click Here To Show Diagram Code: [go]$$Bcm30 New Fuseki? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . O . O O O . . . . | $$ | . . O , O . . . . , . X X X O X . . . | $$ | . . O X . . . . . X . . . . X X O . . | $$ | . . X X . X . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . X W . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . W . W . . . . . . . . . . . . . | $$ | . . . . . . . X . . . . . . . . . . . | $$ | . . . . . X . C . . . . . . . . . . . | $$ | . . . X . C C C . , . . . . . X . . . | $$ | . . . . C C C C . X . . . . . . . . . | $$ | . . . . C C C C . . . . . . . . . . . | $$ | . . . . C C C C . . . . . . . . . . . | $$ ---------------------------------------[/go]

The prospects of black making territory in the marked area seem much higher, due to white's weak group. The same aji might exist as on the empty board, but white can't really think about exploiting it, since white's other group is weak.

As white saves the group, black will naturally get more than if he played a "normal" move as what came to my mind (ignoring the peep, which may be questionable):

Click Here To Show Diagram Code: [go]$$Bcm30 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . O . O O O . . . . | $$ | . . O , O . . . . , . X X X O X . . . | $$ | . . O X . . . . . X . . . . X X O . . | $$ | . . X X . X . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . B . . . , . . . . . X . . . | $$ | . . . . . . . . . X . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

skydyr · Post by **skydyr** » Mon Feb 22, 2016 10:41 am

Click Here To Show Diagram Code: [go]$$Bc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . O . O O O . . . . | $$ | . . O , O . . . . , . X X X O X . . . | $$ | . . O X . . . . . X . . . . X X O . . | $$ | . . X X . X . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . W . . . . . . X . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Well, even in a position like this but without the weak group, a move like :b1:

has some merits because it builds on the black group up the left side and on the top. The tewari presented (5 white star point stones) is very different from this, to the point that regardless of what black played on the bottom, it would feel like black has already fallen behind.

Kirby · Post by **Kirby** » Mon Feb 22, 2016 10:54 am

skydyr wrote:The tewari presented (5 white star point stones) is very different from this, to the point that regardless of what black played on the bottom, it would feel like black has already fallen behind.

Sure. The only thing I want to describe is the feeling I have gotten that the "rules" change when weak groups are involved.

It's difficult for me to articulate this well, but nonetheless, interesting to me.

ez4u · Post by **ez4u** » Mon Feb 22, 2016 4:26 pm

Interestingly 18 below is not found in GoGoD as far as I can see. Invariably Black connects with the attachment at 'a' instead. That applies whether you are Onoda Chiyotaro playing Hashimoto Utaro in 1936 or Cho Han-seung playing Gu Li in 2013.

Click Here To Show Diagram Code: [go]$$Wcm9 3 stone game $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . 1 . . 5 9 . . . . | $$ | . . O , O . . . . , . . a 6 7 X . . . | $$ | . . O X . . . . . . . . . . 8 . a . . | $$ | . . X X . 2 . . . . . . . . . 0 3 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . 4 . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Bill Spight · Post by **Bill Spight** » Tue Feb 23, 2016 11:09 pm

Igo Tsumekata (How to play tsumego) is another ancient book I kind of like. I haven't worked through it all yet, though.

It is by Kobayashi Tetsujiro, 6 dan, and his son, Kentaro, published in 1901. Link to online copy in the Japanese National Library: http://dl.ndl.go.jp/info:ndljp/pid/861034

Here are a couple of problems, one easy, one not.

Click Here To Show Diagram Code: [go]$$W White to play and kill $$ ---------------- $$ . . . . . . . . | $$ . . O O X . . . | $$ . . O X . X . . | $$ . . O X , X X . | $$ . . . O . O O . | $$ . . . O . . . . | $$ . . . . . O . . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$B Black to play and live $$ -------------------- $$ . . . . . . . . O . | $$ . . O . . O O . . . | $$ . . . O . X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Enjoy!

Bill Spight · Post by **Bill Spight** » Fri Feb 26, 2016 11:25 am

Let's tackle the harder problem first.

Click Here To Show Diagram Code: [go]$$B Black to play and live $$ -------------------- $$ . . . . . . . . O . | $$ . . O . . O O . . . | $$ . . . O . X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

It is not obvious, but Black has 1.25 eyes, 0.5 of an eye on the side and 0.75 of an eye in the corner, and has to make another 0.75 of an eye to live. She does this by making 1.5 eyes in the corner.

Click Here To Show Diagram Code: [go]$$B Black to play and live $$ -------------------- $$ . . . . 4 . 5 . W . | $$ . . O 6 1 O O 3 . . | $$ . . . O 2 X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Stage 1 is to get :b3:

and

in place in sente, threatening the :wc:

stone.

Click Here To Show Diagram Code: [go]$$B Variation $$ -------------------- $$ . . . . 7 6 5 4 W . | $$ . . O . 1 O O 3 . . | $$ . . . O 2 X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

White cannot afford to play atari at 4.

Click Here To Show Diagram Code: [go]$$B Life $$ -------------------- $$ . . . . O . X . W 7 | $$ . . O O . O O X a . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Black now has and a half eyes in the corner. Added to the half eye on the side gives two eyes for life. ( :b7:

could also be at "a".) Why one and a half eyes?

Click Here To Show Diagram Code: [go]$$W One eye $$ -------------------- $$ . . . . O . X 1 O X | $$ . . O O . O O X 2 . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

throws in at 1.

White can hold Black to one eye in the corner in gote.

Click Here To Show Diagram Code: [go]$$B Two eyes $$ -------------------- $$ . . . . O . X 3 O X | $$ . . O O . O O X 1 2 | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Black to play can make two eyes in the corner by oshitsubushi, also in gote.

Click Here To Show Diagram Code: [go]$$B Book solution $$ -------------------- $$ . . . . O . X . W 7 | $$ . . O O . O O X 8 . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

In the book White played :w8:

. Black gets 5 points in the corner instead of 3, but still she has only one eye.

Click Here To Show Diagram Code: [go]$$B Under the stones $$ -------------------- $$ . . . . O . X O . X | $$ . . O O . O O X X . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . 7 X 3 | $$ . . . . O . X X 4 2 | $$ . . . . . . X O X 5 | $$ . . . . O . X O X 1 | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

throws in at 4. :w8:

at 2 captures four stones.

After White holds Black to one eye in the corner Black has to pick up half an eye on the side. She does this by an under the stones sacrifice, which is familiar to experienced tsumego solvers.

Click Here To Show Diagram Code: [go]$$B Second eye $$ -------------------- $$ . . . . O . X O . X | $$ . . O O . O O X X . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . X X X | $$ . . . . O . X X W W | $$ . . . . . . X O 9 . | $$ . . . . O . X O . . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

captures the :wc:

stones to make the second eye.

I don't know whether Kobayashi père composed this problem or whether it is a famous ancient problem, but it is pretty cool, isn't it?

Despite the slight flaw of :w8:

. First Black encloses the White stone in the corner in sente, with a throw-in if White tries to connect. Then Black makes one and a half eyes with the 1-1 play, threatening to make two eyes with oshitsubushi. And finally Black plays an under the stones sacrifice to pick up half an eye on the side. Poetic!

Bill Spight · Post by **Bill Spight** » Thu Apr 14, 2016 9:53 am

I'm back!

I just ran across a nice opening problem in an ancient game.

Click Here To Show Diagram Code: [go]$$B Black to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . O . . X . . . . | $$ | . . O , . O . O . , . . . . . , X . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O X X . . . . . . . . . . . . . . . | $$ | . . O . X . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . X . . . . X . O . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

It's easy.

At least if you have seen this kind of play before.

Enjoy!

EdLee · Post by **EdLee** » Thu Apr 14, 2016 9:25 pm

Uberdude · Post by **Uberdude** » Sat Apr 16, 2016 8:25 am

A while ago..

Kirby wrote: If it were my game, I'd first try to make white heavy with a peep, and then I'd take territory on the bottom.
$$Bcm1
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . O . O O O . . . . |
$$ | . . O , O . . . . , . X X X O X . . . |
$$ | . . O X . . . . . X . . . . X X O . . |
$$ | . . X X . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . . 2 1 . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . 3 . . . , . . . . . X . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
Click Here To Show Diagram Code
[go]$$Bcm1 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . O . O O O . . . . | $$ | . . O , O . . . . , . X X X O X . . . | $$ | . . O X . . . . . X . . . . X X O . . | $$ | . . X X . X . . . . . . . . . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . . 2 1 . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . 3 . . . , . . . . . X . . . | $$ | . . . . . . . . . X . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]
There are other moves that might give more pressure to black, but I don't seem to have a clear plan as to how to follow up:

Kirby, I thought of you when Ali Jabarin 1p played move 68 in this KGS game today

:

Bill Spight · Post by **Bill Spight** » Sun Apr 17, 2016 8:50 am

Ed got it right.

Click Here To Show Diagram Code: [go]$$Bcm23 Last big play? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . O . . X . . . . | $$ | . . O , . O . O . , . . . . . , X . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O X X . . . . . . . . . . . . . . . | $$ | . . O . X . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . X . . . . X . O . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

When I was 4 kyu, I think that I probably would have played

, as the last big play of the opening. But that is lackadaisical thinking.

The game was played in 1802 between Yasui Chitoku (W) and Sato Shunsaku. Sato played

, below.

Click Here To Show Diagram Code: [go]$$Bcm23 Yasui Chitoku (W) - Sato Shunsaku $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . O . . X . . . . | $$ | . . O , . O . O . , . . . . . , X . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 5 . . . . . . . . . . . . . . . . . | $$ | . O X X . . . . . . . . . . . . . . . | $$ | . 6 O . X . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 4 3 . . . . . . . . . . . . . . . | $$ | . . O . 2 . . . . . . . . . . . 7 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . X . . . . X . O . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Although

is only a one space extension, it is a dual purpose play, making territory while attacking the White group on the left side. Chitoku jumped out with

. Sato continued the attack with

and

, and still got the two space extension at

.

The game record:

Bill Spight · Post by **Bill Spight** » Sun Apr 17, 2016 9:33 am

Here is another Chitoku game, a castle game vs. Honinbo Retsugen (W)

Click Here To Show Diagram Code: [go]$$Bm31 Retsugen (W) - Chitoku $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O 1 . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . 6 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . X , 2 . . | $$ | . . . O . . . . . 4 . 5 . . . . 3 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I confess that I would have missed

. It is a thick play that counters White's thickness. Not much happens on the top side for some time, now.

Retsugen plays

in the bottom right corner and then, after

, is satisfied to have prevented Black from making an ideal enclosure, and takes the big point at

. Skillful play.

Chitoku contents himself with the extension to

, and then Retsugen jumps to

, a big whole board move.

Click Here To Show Diagram Code: [go]$$Bcm37 What now? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O X . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . 7 . . . . . . . . . . | $$ | . . . . . . . . 5 6 . . . . . . . . . | $$ | . . . 4 . . . . 1 2 . . . . X , O . . | $$ | . . . O 3 . . . . O . X . . . . X . . | $$ | . . . . . . . 8 . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Chitoku makes the standard reducing play at

and then takes kikashi in the corner before extending towards the center.

Where did Chitoku play next? (FWIW, I think that it is the only play.

)

Enjoy!

EdLee · Post by **EdLee** » Sun Apr 17, 2016 10:15 am

Hi Bill,

This one is difficult for me.
I'm not sure if

is already connected back with his friendly stones LL.
If so, then maybe the turn (a) is big, but maybe slow --
cannot tell if jumping to (b) is better.
Also, if

already connected, then W capping at one point below (b) seems annoying.
And if something like (c) can keep W split, maybe it's big.
Locally, (d) is big but globally maybe not urgent.
Is the cut (e) small ?

Click Here To Show Diagram Code: [go]$$Wm44 $$ ---------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O X . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . e O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . b . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . X a . . . . . . . . . | $$ | . . . . . . . . X O . . . . . . . . . | $$ | . . . O . . . . X O . . . . X d O . . | $$ | . . . O X . c . . O . X . . . . X . . | $$ | . . . . . . . 1 . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

bayu · Post by **bayu** » Sun Apr 17, 2016 10:59 am

first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere?

As for your question:

Bill Spight · Post by **Bill Spight** » Sun Apr 17, 2016 4:04 pm

bayu wrote:first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere?

Well, I missed

, so I don't know if I am the person to ask about the block. But the cut at F-15 is no big deal. White can just sacrifice two stones. And the bottom looks big to me at this point. FWIW.

Bill Spight · Post by **Bill Spight** » Tue Apr 19, 2016 6:46 pm

bayu got it right.

Click Here To Show Diagram Code: [go]$$Bcm45 Central turn $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O X . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . 9 . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . X 1 . . . . . . . . . | $$ | . . . . . . . . X O . 4 . . . . . . . | $$ | . . . O . . . . X O . 2 3 . X , O . . | $$ | . . . O X . . . 5 O . X . . . . X . . | $$ | . . . . . . . O 6 8 7 a . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The central turn,

, is big. After White's attach-and-extend Black takes kikashi with

and

, which prevents the White clamp at "a". Then

jumps into the center.

Here is the game record.

Life In 19x19

This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that