Life In 19x19 :: Responding to a 3x3 invasion

Life In 19x19 http://www.lifein19x19.com/

Responding to a 3x3 invasion http://www.lifein19x19.com/viewtopic.php?f=11&t=11482	Page 1 of 1

Author: Drew [ Tue Feb 17, 2015 1:15 am ]

Post subject: Responding to a 3x3 invasion

I'm looking for advice on handling this 3x3 invasion:

Click Here To Show Diagram Code: [go]$$ $$ --------------------| $$ . . . . . . . . . . | $$ . . . . . . 3 . . . | $$ . . . . 2 . . 4 . . | $$ . . . . . . X . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . 1 . . | $$ . . . . . . . . . . | $$[/go]

In a recent game we ended up as:

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

which seemed reasonable but I'm curious if there are better possible outcomes for Black?

Author:	Krama [ Tue Feb 17, 2015 1:53 pm ]
Post subject:	Re: Responding to a 3x3 invasion
play 7 on 2-2 in the corner and try to live with white.

Author:	EdLee [ Tue Feb 17, 2015 2:01 pm ]
Post subject:
Krama wrote: [jump] in the corner Do you think that's the best move for B ?

Author:	Bill Spight [ Tue Feb 17, 2015 2:33 pm ]
Post subject:	Re:
EdLee wrote: Krama wrote: [jump] in the corner Do you think that's the best move for B ? It's not a jump, it's a clamp. But your question is excellent.

Author:	EdLee [ Tue Feb 17, 2015 4:37 pm ]
Post subject:
Thanks, Bill. Many beginners are so happy because they spot a vital point, and they are so excited they "jump" in the placement. So I emphasize the "jump in" bad habit.

Author:	Bill Spight [ Tue Feb 17, 2015 5:22 pm ]
Post subject:	Re:
EdLee wrote: Thanks, Bill. Many beginners are so happy because they spot a vital point, and they are so excited they "jump" in the placement. So I emphasize the "jump in" bad habit. OIC.

Author:	Boidhre [ Tue Feb 17, 2015 7:15 pm ]
Post subject:	Re:
EdLee wrote: Krama wrote: [jump] in the corner Do you think that's the best move for B ? Click Here To Show Diagram Code `[go]$$ $$ --------------------\| $$ . . . . . . . 1 2 . \| $$ . . . . . . X O 4 3 \| $$ . . . . O . X O . O \| $$ . . . . . . X X O . \| $$ . . . . . . . . X 5 \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . X . . \| $$ . . . . . . . . . . \| $$[/go]` Edit: Sorry, forgot to include the reason, this seems to leave fewer ko threats for white later.

Author:	EdLee [ Tue Feb 17, 2015 8:29 pm ]
Post subject:
Hi Boidhre, Boidhre wrote: ko threats for white later. Can B do better ?

Author:	Boidhre [ Tue Feb 17, 2015 8:52 pm ]
Post subject:	Re:
EdLee wrote: Hi Boidhre, Boidhre wrote: ko threats for white later. Can B do better ? Last attempt before bed: Click Here To Show Diagram Code `[go]$$ $$ --------------------\| $$ . . . . . . . 1 2 . \| $$ . . . . . . X O 4 . \| $$ . . . . O . X O . O \| $$ . . . . . . X X O 5 \| $$ . . . . . . . . X 3 \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . X . . \| $$ . . . . . . . . . . \| $$[/go]` Click Here To Show Diagram Code `[go]$$ $$ --------------------\| $$ . . . . . . . 1 2 . \| $$ . . . . . . X O . 5 \| $$ . . . . O . X O 4 O \| $$ . . . . . . X X O . \| $$ . . . . . . . . X 3 \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . X . . \| $$ . . . . . . . . . . \| $$[/go]` No internal ko threat for white in either of them. I spotted alone killed when I first looked at this but it left rather a lot of moves for white to play inside for threats later.

Author:	EdLee [ Wed Feb 18, 2015 5:51 am ]
Post subject:
Hi Boidhre, Click Here To Show Diagram Code `[go]$$ $$ ----------------\| $$ . . . . . b . . \| $$ . . . . X O a . \| $$ . . O . X O . O \| $$ . . . . X X O . \| $$ . . . . . . X c \| $$ . . . . . . . . \| $$[/go]` Food for thought: There may not be any ko the rest of the game. (We don't know yet.) How useful is (a) for Black for the rest of the board ? Same question for (b) and (c).

Author:	Bill Spight [ Wed Feb 18, 2015 8:25 am ]
Post subject:	Re: Responding to a 3x3 invasion
Using my heuristic, compare Click Here To Show Diagram Code `[go]$$Bc $$ --------------------\| $$ . . . . . . . . . . \| $$ . . . . . . X 2 7 . \| $$ . 8 . . O . 1 O . 6 \| $$ . . . . . . X 3 4 . \| $$ . . . . . . . . 5 . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . X . . \| $$ . . . . . . . . . . \|[/go]` with Click Here To Show Diagram Code `[go]$$Bc $$ --------------------\| $$ . . . . . . . . . . \| $$ . . . . . . X 2 8 . \| $$ . 7 . . O . 1 O . 6 \| $$ . . . . . . X 3 4 . \| $$ . . . . . . . . 5 . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . . . . \| $$ . . . . . . . X . . \| $$ . . . . . . . . . . \|[/go]`

Author:	Boidhre [ Wed Feb 18, 2015 10:22 am ]
Post subject:	Re:
EdLee wrote: Hi Boidhre, Click Here To Show Diagram Code `[go]$$ $$ ----------------\| $$ . . . . . b . . \| $$ . . . . X O a . \| $$ . . O . X O . O \| $$ . . . . X X O . \| $$ . . . . . . X c \| $$ . . . . . . . . \| $$[/go]` Food for thought: There may not be any ko the rest of the game. (We don't know yet.) How useful is (a) for Black for the rest of the board ? Same question for (b) and (c). b and c remove some aji from the position over just a I think. Other than that I can't see any effect on the rest of the board other than if the white group's status is left undetermined the black stones are slightly weaker. I don't know if Black should tenuki this with only seeing a corner segment.

Author:	EdLee [ Wed Feb 18, 2015 2:40 pm ]
Post subject:
Hi Boidhre, If at 2-2, then takes in sente -- miai of and : Click Here To Show Diagram Code `[go]$$B $$ ----------------\| $$ . . . . 4 1 2 . \| $$ . . . 6 X O 3 5 \| $$ . . O . X O . O \| $$ . . . . X X O . \| $$ . . . . . . X . \| $$ . . . . . . . . \| $$[/go]` Boidhre wrote: Click Here To Show Diagram Code `[go]$$ $$ ----------------\| $$ . . . . . 1 2 . \| $$ . . . . X O 4 3 \| $$ . . O . X O . O \| $$ . . . . X X O . \| $$ . . . . . . X 5 \| $$ . . . . . . . . \| $$ . . . . . . . . \| $$ . . . . . . . . \| $$[/go]` Above var, instead of connecting at ... takes in sente: Click Here To Show Diagram Code `[go]$$W $$ ----------------\| $$ . . . . 1 B O 7 \| $$ . . . 2 X O 5 B \| $$ . . O . X O . O \| $$ . . . . X X O 8 \| $$ . . . . . . X 3 \| $$ . . . . . . 4 6 \| $$ . . . . . . . . \| $$ . . . . . . . . \| $$[/go]` Conclusion: hane is not a correct move.

Author:	EdLee [ Wed Feb 18, 2015 7:02 pm ]
Post subject:
Hi Boidhre, Click Here To Show Diagram Code `[go]$$ $$ ----------------\| $$ . . . . . . b . \| $$ . . . . X O a . \| $$ . . O . X O . O \| $$ . . . . X X O . \| $$ . . . . . d X c \| $$ . . . . . . . . \| $$[/go]` Locally, each of (a), (b), and (c) kills. (a) and (b) are about the same. (c) -- B has to be careful, because this involves B's liberties, and B has to watch out later, if the (d) ladder becomes good for W. So perhaps the placement (b) and clamp (a) are slightly better. Globally, it depends. Re: Bill, post 12.

Author:	Boidhre [ Wed Feb 18, 2015 7:15 pm ]
Post subject:	Re: Responding to a 3x3 invasion
Thanks Ed, it's been an interesting dissection and shown up some blind spots for me.

Author:	EdLee [ Wed Feb 18, 2015 11:33 pm ]
Post subject:
Boidhre wrote: blind spots for me. Same here.

Page 1 of 1	All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/