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Sente variation for 3-3 invasion of star point
http://www.lifein19x19.com/viewtopic.php?f=11&t=11810		 Page 1 of 1
Author:  gostudent [ Sun May 10, 2015 6:44 pm ]
Post subject:  Sente variation for 3-3 invasion of star point
In Kogo's joseki dictionary, it is suggested that black can play :b4: to get sente:
Click Here To Show Diagram Code
[go]$$Wc Competing for sente
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . a . . . . . . . . . . . . . |
$$ | . . 1 3 b 4 . . . . . . . . . . . . . |
$$ | . . 2 X . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

It then says that white typically play (a) next, and playing at (b) is typically not favorable, and list this sequence (11 - 14 is a, b, c, d)
Click Here To Show Diagram Code
[go]$$Wc One possible sequence
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . a 9 0 . . . . . . . . . . . . |
$$ | . c O O 1 X . b . . . . . . . . . . . |
$$ | . 6 X X 3 2 . . . , . . . . . , . . . |
$$ | . . . 5 4 7 . . . . . . . . . . . . . |
$$ | . . . d 8 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

However, I do not understand why :w7: is played at F15. What if it is played at C15? The three black stones seem to be in trouble. My reading is not good, but it seems that the outcome does not look nice to black. One possible variation is
Click Here To Show Diagram Code
[go]$$c B Will black lost the group?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 2 . . . . . . . . . . . . . . . . . |
$$ | . 1 O O O X . c . . . . . . . . . . . |
$$ | . X X X O X . . . M . . . . . , . . . |
$$ | . 3 O O X b . . . . . . . . . . . . . |
$$ | . 4 5 6 0 . . . . . . . . . . . . . . |
$$ | . 8 7 9 . . . . . . . . . . . . . . . |
$$ | . a . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

and the top two black stones need to run for their life. Maybe this move to compete for sente is only possible when black has a stone around the cross position, so that the two black stones are relative safe? Still, white is out, and it seems that white can live in corner relatively easily by playing at, say, A18.
Author:  Kirby [ Sun May 10, 2015 8:11 pm ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
Depends on the board, but seems simpler to just do this as black:

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


if you really want to tenuki, then consider it here. If not, continue:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 7 . . . . . . . . . . . . . |
$$ | . a 1 3 5 4 8 . . . . . . . . . . . . |
$$ | . 9 2 X 6 . . . . , . . . . . , . . . |
$$ | . 0 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


Then tenuki after 'a'.
Author:  gostudent [ Sun May 10, 2015 10:48 pm ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
Kirby wrote:
Depends on the board, but seems simpler to just do this as black:

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



Thank you for the response. Kogo's joseki dictionary suggests that this is bad for black. -- and that is why I am so confused.

Quote:
if you really want to tenuki, then consider it here. If not, continue:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 7 . . . . . . . . . . . . . |
$$ | . a 1 3 5 4 8 . . . . . . . . . . . . |
$$ | . 9 2 X 6 . . . . , . . . . . , . . . |
$$ | . 0 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


Then tenuki after 'a'.
Author:  schawipp [ Sun May 10, 2015 11:00 pm ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
In your second diagram you can play (b) and threaten a ladder. After white defends you can capture at (a). Maybe the joseki variation depends on that this ladder is working for black.
Author:  DJLLAP [ Sun May 10, 2015 11:01 pm ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
gostudent wrote:
Kirby wrote:
Depends on the board, but seems simpler to just do this as black:

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



Thank you for the response. Kogo's joseki dictionary suggests that this is bad for black. -- and that is why I am so confused.

Quote:
if you really want to tenuki, then consider it here. If not, continue:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . 7 . . . . . . . . . . . . . |
$$ | . a 1 3 5 4 8 . . . . . . . . . . . . |
$$ | . 9 2 X 6 . . . . , . . . . . , . . . |
$$ | . 0 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


Then tenuki after 'a'.


It looks to me like :w5: at E17 instead of F18 forces black into this position. So if this position really is bad for black, :w5: at F18 would seem to be a mistake.
Author:  Kirby [ Sun May 10, 2015 11:22 pm ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
gostudent wrote:
Thank you for the response. Kogo's joseki dictionary suggests that this is bad for black. -- and that is why I am so confused.


Okay, you call Kogo up. Tell him I challenge him to a Malkovich game here on L19!
Author:  mipli [ Mon May 11, 2015 3:16 am ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
Kirby wrote:
Depends on the board, but seems simpler to just do this as black:

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



Josekipedia has this marked as the right place for black to tenuki.

The sequence starting with :b6: at F16 even appear there, but I've seen it before in my games. Might be an old variation that's no longer played.
Author:  ez4u [ Mon May 11, 2015 4:48 am ]
Post subject:  Re: Sente variation for 3-3 invasion of star point
In my database the starting position after :b1: below appears 537 times. White attaches underneath at 'a' next 500 times compared to 24 cases of playing :w2:. Black replies at :b3: 4 times and plays 3 at 4 instead the other 20 times. White continues at :w4: 2 times and hanes at 'b' the other two times. After Black plays :b5: White hanes at 'b' (1 game) or cuts at 'c' (1 game). There is no example of the cut at :w6:. Learn to take what you read in Kogo with a grain of salt. ;-)
Click Here To Show Diagram Code
[go]$$Bc Search Pattern
$$- - - - - - - - +
$$. . . . . . . . |
$$. . a . . . . . |
$$. . 1 2 O O . . |
$$. . 3 4 X X b . |
$$. . c 5 6 . . . |
$$. . . . . . . . |
$$. . . . . . . . |
$$. . . . . . . . |
$$[/go]


It's not just Kogo that describes :b1: as a way to take sente. However, looking at the games in my database, it is perhaps better to call :b1: an offer to take sente. White can resist and in actual practice Black ends in gote here more often than not.
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