Koroviev wrote:amnal wrote:$$
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$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 x . .
$$ |. . . x x . . . .
$$ |. . . . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ -------------------
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 x . .
$$ |. . . x x . . . .
$$ |. . . . . . . . .[/go]
This sequence is bad, of course, and we might even say it's
clearly wrong. White is making bad shape and probably doesn't have any very strong followups.
Can you explain why this is so bad? Thanks.
Well, as in my post I have to be very careful when saying if it's actually bad or how bad it is. Nevertheless, I think it probably is bad and a group of players encountering it for the first time would probably come to that conclusion.
The big reason is that I'd perceive that white can do
better. In this shape, black can just play a jump from the corner:
$$
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$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 x . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . 5 . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ -------------------
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 x . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . 5 . . . . . .[/go]
...and what's white going to do? Push from behind at x? Actually, this would end up in a position from another joseki that doesn't come up much...probably because white isn't happy to have pushed from behind.
Alternatively, black can just push up:
$$
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$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 5 . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ -------------------
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . .
$$ |. . 1 , . 4 5 . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . . . . . .[/go]
And in this case, it feels like white will have a tough time because he doesn't have strength to attack the corner properly - his shape is bad. Lets compare to another shape that's more common:
$$
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$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . 7
$$ |. . 1 , . 6 4 5 .
$$ |. . . . . . . . .
$$ |. . . 8 . . . . .
$$ |. . . . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ -------------------
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 . 7
$$ |. . 1 , . 6 4 5 .
$$ |. . . . . . . . .
$$ |. . . 8 . . . . .
$$ |. . . . . . . . .[/go]
In a shape like this, white can play the pressing pincer at 8 because he's become stronger in sente. Compare to our non-joseki where black has the vital point at 4 instead of white, making white's shape vitally weaker if black gets a chance to push out.
Black can play differently of course, such as:
$$
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$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 8 .
$$ |. . 1 , . 6 4 5 .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . 7 . . . . . .
- Click Here To Show Diagram Code
[go]$$
$$ -------------------
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . . . 2 . 3 8 .
$$ |. . 1 , . 6 4 5 .
$$ |. . . . . . . . .
$$ |. . . . . . . . .
$$ |. . 7 . . . . . .[/go]
But then white can live with the move at 8, unlike in the game where he has bad shape and hasn't created a cut in black. I'll note that whilst this is more of a joseki than the bad shape we're discussing, nor is it the most popular sequence around for various reasons. It's a useful comparison that's well studied, though.
Of course, maybe the difference won't come to much. Even if this is bad for white, it likely isn't by a game losingly large amount except for pretty strong players...I know I could certainly contrive to lose the game as black!
So, I say it's bad because I know more common sequences that white could play which lead to a similar but (at least to my initial inspection) better shape for him. I often make this a big theme in teaching, actually, many common mistakes are more clearly mistakes when phrased in comparison to a more enthusiastic move that the opponent cannot resist and so is almost always better.
In simple terms, it's bad simply because it doesn't give white good shape and it asks black to take good shape by pushing up. After that, white doesn't have time to simultaneously make his stones strong and attack something, but if black easily gets strong on both sides then white hasn't gained anything and could have almost certainly done better with slightly different initial moves.
Edit: This feels all a bit confused, partly because I'm trying hard not to make absolute statements because it's a complex position and it's always possible to contrive a situation where the 'bad' move is good or to start a fight that makes the superior position unclear even if there is one. To be concise, I'd say that white's move helps black but does not help white, for all the reasons that this kicking shape (or is this more of a high five?) usually is bad. White retains shape weaknesses, black makes good shape. Whatever white's goal is, he has a better move to accomplish that goal, such as by playing one move further and attaching on top of black.
...)
) of people playing out a "joseki" they learned for the 3rd line on the 4th line, where it makes very little sense. You see it in all my 9x9 games, where I inevitably approach a 3-4 stone from the 2-4 point, under the impression that I'm making a 3-4 approach to a 5-4 stone.
is very solid, and definitely keeps Black separated. From a shape standpoint, however, 
and 
, which leaves a cutting point at "a", a Black weakness.
Black will not respond at "a", but will extend at 
, jump to "b", or play somewhere else. The cutting point is gone forever. 
Here was my suggestion, which may have gotten lost among other things that I wrote: 
