Pros/Cons? It takes away liberty when white descends as in ladder variation, so I wonder about cons of the move, in particular.
Author:
moyoaji [ Thu Nov 14, 2013 12:09 am ]
Post subject:
Re: Joseki Question
I looked this up at DailyJoseki and BruGo.BE - both have the descend variation. However, BruGo.BE says the variation is only "almost joseki" and not a true joseki and DailyJoseki's database only has this move being played 5 times. My guess is that the result is not as good for black. Here is the full "almost joseki."
My thought is that the marked white stone still has too much potential on the right while white seems to have gotten too many points with too much top potential - in sente - for a joseki that started with white approaching. Since black was the first in the corner he should get a better result than white.
The full ladder joseki, on the other hand, gives white a big corner in exchange for being either sealed in or giving black the aji of an enormously important ladder - all while black comes away with sente.
[go]$$Bc Marked move can seal white in $$ -------------------------------------- $$ |. . . . . . . . . . . O . O O . . X .| $$ |. . . . . . . . . X O O O X X X X O .| $$ |. . . . . . . . . . X . O X O O O O .| $$ |. . . , . . . . . , . X O X O O X . .| $$ |. . . . . . . . . . . . X O X . X . .| $$ |. . . . . . . . . . . . . O X . X . .| $$ |. . . . . . . . . . . . B . X O . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . , . . . . . , . . . . . , . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . , . . . . . , . . . . . , . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ |. . . . . . . . . . . . . . . . . . .| $$ ---------------------------------------[/go]
Author:
Kirby [ Thu Nov 14, 2013 12:15 am ]
Post subject:
Re: Joseki Question
Edit: Post made before reading moyoaji's preceding post!
The best I have come up with so far is that maybe this allows white to play this way because of black's shape (if black tenuki after white defends cut):
Thanks, moyoaji. Looks like you posted between my last two.
The "almost joseki" variation is interesting, but doesn't look at bad for black to me. For example, even if the ladder was good for white, black was able to force white not to play that way.
However, you make a good point about potential of the stone. White doesn't play o14 in the variation you provided.
On the other hand, if the almost joseki is good for white, why can't white play 12 in response to the "normal" black 11 at r15 to achieve a similar result, as shown below?
BruGo.BE actually says the below result is a basic joseki. My guess is that it was once a joseki but then white found a stronger response by fixing the cut directly to leave more aji on the right with his stone since black's honobi seriously damages that stone. Also, black ends this in sente because he doesn't have to worry about white's right-side stone.
As for playing that way in response to the connection, that result is also an "almost joseki" on BruGo.BE but has been played over 30 times in the DailyJoseki database. Usually, however, black usually plays tenuki instead of making a base on the right. I'm not sure why this is viewed as sub-optimal, and I'm not sure whether it is less good for white or for black. Perhaps it is seen as less good for white and this is how white plays when he does not have the ladder? The push to O14 is a nice move to limit black's influence and get white out toward the center. Perhaps that move is valuable enough that white needs to play it to get a good result since the black group is so firm when connected this way?
I'd be interested to hear the thoughts from dan-level players. I've never done much study of Magic Sword variations.
Also according to "The 21st Century Dictionary of Basic Joseki" White 'b' is too severe a threat in some situations, so Black will still often play at 'a'.
Regarding the ladder: I guess White should definitely not play this Joseki (descending instead of hanging connection) when the ladder works for Black or when Black has a severe ladder block threat.
I think black could get a favorable result from the cut. Not killing directly, but using the threat of cutting and killing. Black can win the capturing race against the 3 white stones if white ignores the situation, and can crawl to safety threatening the corner if white does not play so everything seems forced.
That corner is only about 14 points for white while black has more or less sealed him in. That seems like it would usually be good for black on an open board.
Author:
SoDesuNe [ Thu Nov 14, 2013 1:51 am ]
Post subject:
Re: Joseki Question
Black has some nice forcing moves, that's right. But while getting a wall with some defects and a semi-enclosing, Black managed to kill all the tension that was left in White's position. Depends of course of the board, but if it's empty, I would call it Aji-Keshi.
I think, it's also important to see that Black has forcing moves anyway against White's shape, without sacrificing three stones and solidifying White in the process - like i.e. 'a' below.
post scriptum: I just searched in GoGoD and I found two cases where the cut was played in the "normal" Joseki. Both times they did not play the descend to but cut directly at . So maybe, White can counter with connecting at ? Seem quite wild and I'm bad at capturing races but worth a thought =D
Author:
Loons [ Thu Nov 14, 2013 1:53 am ]
Post subject:
Re: Joseki Question
Another way I always think of this situation is that white having played both sides of a bamboo joint is nice (enough) for black anyway.
Author:
Kirby [ Thu Nov 14, 2013 1:53 am ]
Post subject:
Re: Joseki Question
@SoDesuNe:
Thanks for the reference to "The 21st Century Dictionary of Basic Joseki".
What particularly strikes me as relevant to my curiosity is your comment:
Quote:
White 'b' is too severe a threat in some situations
Was there any detail on this?
Author:
logan [ Thu Nov 14, 2013 2:02 am ]
Post subject:
Re: Joseki Question
While we're on the topic of this joseki family, may I also ask about a couple of other variations?
The following were all under research several years ago, I didn't know if any consensus had been reached on them yet. Maybe someone with that new Takao joseki dictionary can show what it says in there.
Thanks for the reference to "The 21st Century Dictionary of Basic Joseki".
What particularly strikes me as relevant to my curiosity is your comment:
Quote:
White 'b' is too severe a threat in some situations
Was there any detail on this?
Sadly no. But I also don't find any pro games with this Joseki in GoGoD Summer 2012.
Here is a game where the cut moyoaji and I were discussing was described as a Tesuji, although Black made a mistake shortly after in not netting White's stones. The attachment instead of the bump is the modern move order of the Joseki. A 2003 game commentary by Dinerchtein claims Cho Chikun invented the attachment in 2000.
White following up with 'a' is Joseki in "The 21st Century Dictionary of Basic Joseki". But it is marked as a "quasi-Joseki". In pro games, it seems it was popular in 2009 and since then it was last played (in my copy in 2011). No one ever played 'a'. The popular choice then was Hane with 'b', which leads to some fighting when the players whish it.
This is not included in the book - I also have zero professional games with this. But the following Joseki was popular (latest fashion) in 2003 according to comments by Dinerchtein:
Currently the following is an example of the main line in this joseki (via GoGoD plus updates from Go News and Go4Go for 2013). Since the beginning of 2012 about 80% of games (45 of 57 games in my current database) have as shown instead of the older play at . There are various minor branches along the way with 26 of the games going all the way through to the position shown. From here White most often plays elsewhere.
The best I have come up with so far is that maybe this allows white to play this way because of black's shape (if black tenuki after white defends cut):
Could you provide some examples? I think if I understand this part, it really answers what I was curious about. Why is 'a' so threatening here and not when black 2 is at 'd'?
Author:
Kirby [ Thu Nov 14, 2013 8:14 am ]
Post subject:
Re: Joseki Question
Bill Spight wrote:
Kirby wrote:
The best I have come up with so far is that maybe this allows white to play this way because of black's shape (if black tenuki after white defends cut):
Besides which, after it is easy for Black to throw away his corner stones.
I very much agree. You are correct in that I thought something like white 9 must have been a weakness present in the given variation compared to joseki, but like I said, it feels sloppy.
Perhaps "vulgar" is a better way of putting it than sloppy. In any case, it doesn't seem correct, which is why I am curious about the apparent solution of white having potential at 'a':
It's still not clear to me about why 'a' is so different here than if black 2 is at 'd'.
If White descends at below, Black would like to be able to play from below around "a" to prevent White extending. However, is sente so Black has no eyes here.
When Black plays the marked stone below instead of "a", the descent at "b" pretty much goes away as a threat. So White goes ahead and exchanges for before finishing with or "c" in the corner.
at 'a'.
so everything seems forced.
. So maybe, White can counter 
as shown instead of the older play at 
. There are various minor branches along the way with 26 of the games going all the way through to the position shown. From here White most often plays elsewhere.
, 
it is easy for Black to throw away his corner stones. 
before finishing with