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Chinese opening approach joseki
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Author:  Shawn Ligocki [ Sun Jul 06, 2014 8:13 pm ]
Post subject:  Chinese opening approach joseki
I'm trying to understand the reasons behind every Joseki move I play, and I've stumbled upon one in the standard Chinese opening approach pattern that I don't understand. Why does White respond at :w2: below? Every time I play :b1: I'm afraid White will not respond this way and I'll have no idea how to follow up.

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . a . . . |
$$ . . O b O . . |
$$ . X 1 2 . . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


This seems a little meek for White because it still leaves the exchange Black a, White b and it's not clear to me what Black's follow-up is if White doesn't defend here.

I guess that if White totally Tenukis then White has a good follow-up with the wedge?

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . b . . . |
$$ . . O 3 O . . |
$$ . X 1 a . . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


Then neither a nor b look good for White. But what if White connects solidly? (maybe getting the move at a first)

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X a . |
$$ . . . . . . . |
$$ . . O 2 O . . |
$$ . X 1 . . . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


This push doesn't look very good:

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . . . |
$$ . . O 2 O . . |
$$ . X 1 3 4 . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


Is there some better way to exploit this weakness?
Author:  Shawn Ligocki [ Sun Jul 06, 2014 8:15 pm ]
Post subject:  Re: Chinese opening approach joseki
Hm, after looking over this a bit more I see that maybe :b3: is a very strong attack:

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . a . |
$$ . . O 2 O . . |
$$ . X 1 4 3 5 . |
$$ . . . O . . . |
$$ . X . , O . b |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


This looks at both a and b as miai for connecting out, right?

This does look pretty bad for White.
Author:  Shawn Ligocki [ Sun Jul 06, 2014 8:22 pm ]
Post subject:  Re: Chinese opening approach joseki
Hm, well how about if White pushes at :w2: first. Now that jump into Black a doesn't look quite so good.

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , 5 3 . |
$$ . . . . X 2 . |
$$ . . . . . 4 . |
$$ . . O 6 O . . |
$$ . X 1 . a . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


Is this still good for Black? Or should Black have played differently, for example :b5: at :w6:?
Author:  EdLee [ Sun Jul 06, 2014 9:32 pm ]
Post subject: 
Shawn Ligocki wrote:
I see that maybe :b3: is a very strong attack:
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . a . |
$$ . . O 2 O . . |
$$ . X 1 4 3 5 . |
$$ . . . O . . . |
$$ . X . , O . b |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------[/go]
This does look pretty bad for White.
This :b3: seems to make a pretty bad shape for Black.
Author:  Uberdude [ Sun Jul 06, 2014 10:43 pm ]
Post subject:  Re: Chinese opening approach joseki
Shawn Ligocki wrote:
Hm, well how about if White pushes at :w2: first. Now that jump into Black a doesn't look quite so good.

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , 5 3 . |
$$ . . . . X 2 . |
$$ . . . . . 4 . |
$$ . . O 6 O . . |
$$ . X 1 . a . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


Is this still good for Black? Or should Black have played differently, for example :b5: at :w6:?


This white shape is not locally alive. Black should not try to kill it because it is not surrounded but if in later fighting white loses the option to escape then black could kill it. In the joseki shape white is 100% alive so can play more freely elsewhere. For example black n8 is not sente so if black played that move to develop the centre white could reduce the centre but with your shape white might need to answer locally so then black would have sente to play another move to develop the centre.

So one reason to block the push is to maximise eye space. Another is to take a liberty from p6 which makes pushing out at o7 more powerful (black can't double hane, and even hane is dangerous with the cut).
Author:  EdLee [ Sun Jul 06, 2014 11:27 pm ]
Post subject: 
Shawn Ligocki wrote:
I see that maybe :b3: is a very strong attack:
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . a . |
$$ . . O 2 O . . |
$$ . X 1 4 3 5 . |
$$ . . . O . . . |
$$ . X . , O . b |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------[/go]
This does look pretty bad for White.
Hi Shawn,

In addition, two things about (a) and (b). We look at (a) first:
If B simply plays (a) = :bc: directly, then locally W is not alive.
This way, B does not reduce his own libs,
does not make a bad shape for himself,
and does not hurt his own outside stones.
Jumping in with :b3: is a bad idea in this case.
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . B . |
$$ . . O . O . . |
$$ . X . . . . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------[/go]
Author:  EdLee [ Sun Jul 06, 2014 11:31 pm ]
Post subject: 
Shawn Ligocki wrote:
I see that maybe :b3: is a very strong attack:
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . . . |
$$ . . O 2 O . . |
$$ . X 1 4 3 5 . |
$$ . . . O . . c |
$$ . X . , O . b |
$$ . . . X O . d |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------[/go]
This looks at both a and b as miai for connecting out, right?
Hi Shawn,

The other thing is B (b) does not work:
W can resist with either W (c) or W (d).
To connect back, the shape is either kosumi B (c) or B (d).
Author:  logan [ Mon Jul 07, 2014 2:46 am ]
Post subject:  Re: Chinese opening approach joseki
Click Here To Show Diagram Code
[go]$$B :w2: tenuki
$$ . . . . . . . . . . . |
$$ . , . . . . . , . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . . . . . |
$$ . . . . . . O b O . . |
$$ . . . . . X 1 3 a . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

If White tenukies, Black should simply push making miai of 'a' and 'b'.

Click Here To Show Diagram Code
[go]$$B :w2: tenuki
$$ . . . . . . . . 8 . . |
$$ . , . . . . . , . . . |
$$ . . . . . . . . Y . . |
$$ . . . . . . . 4 6 . . |
$$ . . . . . . O 3 O . . |
$$ . . . . . X 1 5 7 . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

It's bad to wedge as Black's stone can become damaged and White gain's more options to settle.

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

White 'a' and 'b' are miai. But Black prefers White 'a' over 'b' for the Low-Chinese opening.

Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . . . . . |
$$ . , . . . . . 3 a . . |
$$ . . . . . . 4 2 X d . |
$$ . . . . b . . c . 1 . |
$$ . . . . . . O . O . . |
$$ . . . . . X X O . . . |
$$ . . . . . . . O . g . |
$$ . X . . . X . f O . . |
$$ . . . e . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

If :b1:, then between 'a' and 'b' White either settles -- better than if Black had played 'c' and allowed White 'd' -- or moves out into the center taking Black's key expanding point for his bottom moyo around 'b' and exacerbating White's invasion at 'e'. Black 'f' for 'g' may no longer be sente when the time comes. Black's choice of which direction to attack White becomes worse.

Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . . . . . |
$$ . , . . . . . . 5 3 . |
$$ . . . . . . . . X 2 . |
$$ . . . . . . . . . 4 . |
$$ . . . . . . O 6 O . . |
$$ . . . . . X 1 a . b . |
$$ . . . . . . . O . c . |
$$ . X . . . X . , O . . |
$$ . . . d . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

If :w6: rather than 'a', then White 'b' or 'c' later makes worse eye potential, leaves more bad aji, and gives Black's stones an extra liberty. The liberty could become crucial in the variations following White's invasion at 'd'.

I hope this answers your questions.
Author:  Uberdude [ Mon Jul 07, 2014 3:18 am ]
Post subject:  Re: Chinese opening approach joseki
Another thought about the attach of 2: it allows black to trade like this: cutting off the marked stone and building powerful centre thickness in exchange for letting white into the right side. In the chinese opening probably this is good for white if black was trying to make points at the top right, but it gives black a choice. If white thought the centre wasn't important why did he play the marked stone?

Click Here To Show Diagram Code
[go]$$B (7 onwards just for example)
$$ . . . . . . 9 . . . . |
$$ . , . . . . . . 6 8 . |
$$ . . . . . . . 7 X 2 . |
$$ . . . . . . . . . . . |
$$ . . . . . . W 5 O . . |
$$ . . . . . X 1 3 4 . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]


If you prefer the right, white can choose this one. I seem to recall Rui Naiewei played it a few times.

Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . 2 X . . |
$$ . . . . . . . |
$$ . . . . O . . |
$$ . 1 . . . . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]
Author:  drmwc [ Tue Jul 08, 2014 8:07 am ]
Post subject:  Re: Chinese opening approach joseki
Hre is another idea for black if white tenukis:
Click Here To Show Diagram Code
[go]$$B shut white in
$$ . . . . . . . . . . . |
$$ . , . . . . . . 7 5 . |
$$ . . . . . . . . X 4 . |
$$ . . . . . 3 . 1 . 6 . |
$$ . . . . . . O 2 O . . |
$$ . . . . . X X . . a . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]


Black can shut white in. This may well be sente - white will need to read a bit to see if another move is needed. (I would be quite nervous in white's place about a black attack at a.)

Black could also play 3 to take white's eyes away:
Click Here To Show Diagram Code
[go]$$B Attack!!! :rambo: :rambo: :rambo: :rambo: :rambo: :rambo:
$$ . . . . . . . . . . . |
$$ . , . . . . . . . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . 1 . 3 . |
$$ . . . . . . O 2 O . . |
$$ . . . . . X X . . . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

White's group is very weak. This line is unlikely to be a fun game for him. So maybe white will try this:

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


Black then has various options e.g.


Click Here To Show Diagram Code
[go]$$B Hairy
$$ . . . . . . . . . . . |
$$ . , . . . . . . . . . |
$$ . . . . . . . . X 2 . |
$$ . . . . . . . 1 4 3 . |
$$ . . . . . . O . O 5 . |
$$ . . . . . X X . . . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]


The move above may be possible - it depends on the surrounding areas.It's difficulat to read this one out, but it feels that it may be good for black. For example:



Click Here To Show Diagram Code
[go]$$W Hairy line again
$$ . . . . . . . . . . . |
$$ . , . . . . 8 . 4 2 . |
$$ . . . . . . 6 3 X O . |
$$ . . . . 9 . 7 X O X . |
$$ . . . . . . O 5 O X . |
$$ . . . . . X X . . 1 . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]


White needs to play at 5 to keep his group together. Then black 6 is quite severe- white gets a weak group sandwiched between strong black groups.
Author:  Shawn Ligocki [ Sat Jul 12, 2014 8:57 am ]
Post subject:  Re: Chinese opening approach joseki
Thanks for the feedback everyone!

EdLee wrote:
Shawn Ligocki wrote:
I see that maybe :b3: is a very strong attack:
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . . |
$$ . . . , . . . |
$$ . . . . X . . |
$$ . . . . . . . |
$$ . . O 2 O . . |
$$ . X 1 4 3 5 . |
$$ . . . O . . c |
$$ . X . , O . b |
$$ . . . X O . d |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------[/go]
This looks at both a and b as miai for connecting out, right?
Hi Shawn,

The other thing is B (b) does not work:
W can resist with either W (c) or W (d).
To connect back, the shape is either kosumi B (c) or B (d).


Oh right! I remember now that that was one of the first few problems in "The Art of Connecting Stones". Now I just need to remember it during games.

logan wrote:
Click Here To Show Diagram Code
[go]$$B :w2: tenuki
$$ . . . . . . . . . . . |
$$ . , . . . . . , . . . |
$$ . . . . . . . . X . . |
$$ . . . . . . . . . . . |
$$ . . . . . . O b O . . |
$$ . . . . . X 1 3 a . . |
$$ . . . . . . . O . . . |
$$ . X . . . X . , O . . |
$$ . . . . . . . X O . . |
$$ . . . . . . . . X X . |
$$ . . . . . . . . . . . |
$$ ----------------------[/go]

If White tenukies, Black should simply push making miai of 'a' and 'b'.


This does look much better and calmer.
Author:  Shawn Ligocki [ Sat Jul 12, 2014 9:25 am ]
Post subject:  Re: Chinese opening approach joseki
Uberdude wrote:
Shawn Ligocki wrote:
Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . |
$$ . . . , 5 3 . |
$$ . . . . X 2 . |
$$ . . . . . 4 . |
$$ . . O 6 O . . |
$$ . X 1 . a . . |
$$ . . . O . . . |
$$ . X . , O . . |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]



This white shape is not locally alive. Black should not try to kill it because it is not surrounded but if in later fighting white loses the option to escape then black could kill it. In the joseki shape white is 100% alive so can play more freely elsewhere.


Thanks Uberdude, I'm trying to read out why this shape is not locally alive. But I cannot figure out how to kill. Here is the best that I've gotten:

Click Here To Show Diagram Code
[go]$$Bc White gets two eyes.
$$ . . . . . . . |
$$ . . . , X X . |
$$ . . . . X O 7 |
$$ . . . . . O 8 |
$$ . . O O O 9 . |
$$ . X X 1 2 . 6 |
$$ . . . O . 4 3 |
$$ . X . , O 0 5 |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


Click Here To Show Diagram Code
[go]$$Bc White also lives.
$$ . . . . . . . |
$$ . . . , X X . |
$$ . . . . X O . |
$$ . . . . . O . |
$$ . . O O O 8 . |
$$ . X X 1 2 . 6 |
$$ . . . O . 4 3 |
$$ . X . , O 5 7 |
$$ . . . X O . . |
$$ . . . . X X . |
$$ . . . . . . . |
$$ --------------+[/go]


I am trying to follow the philosophy of reducing from the outside first, but maybe this is a case where you need to hit a vital point inside first?

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


Which does look pretty dead for White, but I'm not convinced all those moves should have been forcing. Is there a better way?
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