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Kobayashi 2 formation thoughts
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Author:  Mark356 [ Thu Nov 11, 2010 2:41 pm ]
Post subject:  Kobayashi 2 formation thoughts
I was just browsing SL, and found a page on the Kobayashi 2 formation that made me think a bit. (The page is here: http://senseis.xmp.net/?CornerCoOrdinationStatistics and suggests that Black wins more with the Kobayashi 2 than with the Orthadox fuseki.)

The Kobayashi 2 formation is this:


Click Here To Show Diagram Code
[go]$$c Kobayashi 2 formation.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 4 . . . . . , . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . c . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 5 . . |
$$ | . . . 2 . . . . . , . . . . . , . . . |
$$ | . . . . . a . . . b . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]



Black 5 is what's characteristic of the Kobayashi 2. It's interesting, because for the Orthadox fuseki, Black's shimari faces his own corner stone, not his opponent's corner stone. The idea is to build a large-scale structure, so normally White plays a wedge as the third move.

Here, however, the situation is the opposite. Black's shimari is aiming at the lone white stone in the corner. If Black can later approach at "a", his situation will be very good, especially if White has a good reason not to play a pincer.


In fact, since letting Black play at "a" is so good, usually White responds to 3 with a play near "a" or "b" to prevent this. Black might then approach from the other side at "c", or else approach the other stone. But even if Black completely ignores the white response, the initial fighting is over a neutral side, not one that Black is trying to claim.

Also, often when White responds to Black 3 near "b", Black plays on the other side of it, near "a". In this case the influence his shimari contributes in that direction might help him in the ensuing fight.

I think the theory is that if a shimari can be said to affect whatever corner it faces, the best position for it is not the one which threatens to make the largest structure, since that kind of large structure can easily be broken up. The best position for it is facing an enemy stone, forming a mild attack.

Any thoughts on the matter?
Author:  Dusk Eagle [ Thu Nov 11, 2010 4:46 pm ]
Post subject:  Re: Kobayashi 2 formation thoughts
Quote:
(The page is here: http://senseis.xmp.net/?CornerCoOrdinationStatistics and suggests that Black wins more with the Kobayashi 2 than with the Orthadox fuseki.)

It's interesting, but I really would like to see some more recent statistics on it. Fuseki knowledge is constantly growing, and what was valid a few years ago may be viewed as inferior now.

I'd like to look more into this fuseki, but I've never actually seen it occur in a game I've studied, and I have to run to class now. However, this explanation just doesn't feel quite right to me:
Quote:
I think the theory is that if a shimari can be said to affect whatever corner it faces, the best position for it is not the one which threatens to make the largest structure, since that kind of large structure can easily be broken up. The best position for it is facing an enemy stone, forming a mild attack.

Large structures that can be broken up are still fine, as you can profit off of the forcing moves you get when white wedges in between your stone. Also, to say that the shimari "mildly attacks" white's stone is not really true.

I wonder, too, about how this fuseki has changed since 2002 now that this pincer has become more common:

Click Here To Show Diagram Code
[go]$$c Kobayashi 2 formation.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 4 . . . . . , . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 7 . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . , . . . . . , 3 . . |
$$ | . . . . . . . . . . . . . . 5 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

As another quick thought before I run off late to class, don't forget about this similar-yet-different opening, which I quite enjoy playing:

Click Here To Show Diagram Code
[go]$$c Kobayashi 2 formation.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 1 . . . |
$$ | . . . 4 . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . , . . . . . , 3 . . |
$$ | . . . . . . . . . . . . . . 5 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Author:  Mark356 [ Thu Nov 11, 2010 7:52 pm ]
Post subject:  Re: Kobayashi 2 formation thoughts
That last one used to be my very favorite opening as black-- it's very safe and has good development potential.

I'm not sure if I quite articulated what I think the benefit of this formation might be. It's not that it's a particularly aggressive opening for black. But black does have a very good approach move with this shimari. Also, I think there's something to be said for having a shimari face the rest of the board rather than just your other corner.

Btw, I'm a bit surprised that you haven't seen it in games you've studied. I meant to post some SGFs here anyway.
[sgf-full]http://www.lifein19x19.com/forum/download/file.php?id=531[/sgf-full]
[sgf-full]http://www.lifein19x19.com/forum/download/file.php?id=532[/sgf-full]
[sgf-full]http://www.lifein19x19.com/forum/download/file.php?id=535[/sgf-full]

Attachments:
o-mok.sgf [980 Bytes]
Downloaded 656 times
File comment: Fujisawa Hosai's opening technically isn't the same, since he opens on 3-3 rather than 4-4, but since I'm most interested in the function of the shimari, I'll count it. Go Seigen's response to black 3 prevents the ideal development. I thought that Hosai did end up using the shimari later in the fighting.
seigenhosai.sgf [1.54 KiB]
Downloaded 652 times
File comment: I think this game shows the ideal development from the formation.
hideokoichi.sgf [2.2 KiB]
Downloaded 682 times
Author:  Dusk Eagle [ Thu Nov 11, 2010 11:45 pm ]
Post subject:  Re: Kobayashi 2 formation thoughts
I looked up black's side position from moves 1-5 in eidogo.com's pro game database just now. Looking only at games dated 2000 or later, it appears to be just like you said: by far the most common move seemed to be :w6: or 'a'.

Click Here To Show Diagram Code
[go]$$Bc Kobayashi 2 formation.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . b . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 5 . . |
$$ | . . . W . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . a 6 . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

This seems to suggest that letting black get the approach on the lower left stone is indeed very big, and white will more often than not play to prevent it. In fact, even if :wc: was on the 3-4 or 3-3 point, :w6: seems to be the most popular reply.

If black black does approach around 'b', it seems perfectly fine for black, but I don't see it being a concern for white either. The game feels pretty close to even to me.

Still, I don't understand exactly what this fuseki has going for it compared to the Orthodox fuseki. The fact that :w6: duals as both an extension from white's corner and limits an extension from black's shimari seems slightly unfavorable to me. The low :b5: stone also slightly lowers the value of the right side compared to the Orthodox fuseki.

Quote:
the initial fighting is over a neutral side, not one that Black is trying to claim.

I don't understand how that is an advantage for this fuseki. If anything, I want the fight to be in my strongest area, as it will give me the strongest attack on white and allows white to do the least back to me.

Of course, this is all just my feelings on this fuseki; you shouldn't draw any conclusions based solely on what I say :). To me though, I don't like it as much as the more common fuseki, yet it does seem to appear in pro play anyway. It'd be interesting to hear how a pro feels about this fuseki.
Author:  Loons [ Fri Nov 12, 2010 4:17 am ]
Post subject:  Re: Kobayashi 2 formation thoughts
A KGS game I just saw transposed onto this Kobayashi 2. Just out of interest.
Author:  Chew Terr [ Mon Nov 15, 2010 1:33 pm ]
Post subject:  Re: Kobayashi 2 formation thoughts
The most recent Go Commentary covers a Sakata Eio game where he plays this opening. The opening isn't discussed much, but it's worth seeing one more example of how it can turn out.

http://www.gocommentary.com/free-videos ... ecial.html
Author:  Magicwand [ Mon Nov 15, 2010 1:42 pm ]
Post subject:  Re: Kobayashi 2 formation thoughts
kobayashi 2 formation is considered not optimal during the time he played it.
but he was winning with that formation so people started to appreciate it more.

it doesnt really matter what formation you start your fuseki. it really matters during the middle game. specially if you are kyu level.. it doesnt matter what fuseki you play.
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