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 Post subject: Question about 4-4 Small Knight Joseki
Post #1 Posted: Sun May 12, 2019 3:27 pm 
Lives in gote

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I was helping out someone from my local club by putting together some of the basic sequences for dealing with the 4-4 small knight enclosures. But I realized that I'm not sure why two sequences are evaluated as I think they usually are. One of those cases again where the one who learns the most is the teacher ;-)

Starting from an obviously contrived position -- As I understand it, the following position that starts from the 3-3 invasion and aiming to live outright is not good because black ends in gote, gets a small, surrounded corner, and white gets a nice wall:

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . O O . |
$$ | . . . . . . . . . . . . . . . . O X . |
$$ | . . . O . . . . . , . . . . . O X X . |
$$ | . . . . . . . . . . . . . O . O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]


While the sequence following the 3-4 belly attachment is considered better, and if white decides to take the outside this is the result:

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


Lizzie seems to agree. At least in the above diagrams, she gives white about 65% in the latter diagram and 71% in the former. That said, there are some big similarities in the positions. White gets sente, black lives fairly small and surrounded in the corner, and white gets a good bit of influence. Is the main difference in the evaluation that in the second diagram, white's wall is weaker due to the cut at A? That said, a 5 percent difference in Lizzie seems much smaller than I would have expected given the disdain strong players usually have for the first position.

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 Post subject: Re: Question about 4-4 Small Knight Joseki
Post #2 Posted: Sun May 12, 2019 3:38 pm 
Honinbo

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BlindGroup wrote:
That said, a 5 percent difference in Lizzie seems much smaller than I would have expected given the disdain strong players usually have for the first position.


I have occasionally seen a play that humans have abandoned given only a 2% winrate loss by LZ or other strong bot, a difference that is within the margin of error of the bot. But humans will typically have a reason that the play is inferior. Reason can be powerful. :)

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 Post subject: Re: Question about 4-4 Small Knight Joseki
Post #3 Posted: Tue May 14, 2019 5:11 am 
Judan

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Although your question is just about the end position and why the bot win% difference is smaller than expected, for starters your presumed sequence is not a one-way street: locally speaking we usually say it's just a ko for life. If black connects at 7 then white can kill the corner locally with hane at b instead of the hanging defence. Black can then clamp and crawl along the 2nd line to live but it's pretty sad, but actually white letting black live might be better (here the outside is nice big potential). So 7 is usually one line right for a ko.
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . 4 . . |
$$ | . . . O . . . . . , . . . . . O 3 b . |
$$ | . . . . . . . . . . . . . a . 2 1 . . |
$$ | . . . . . . . . . . . . . . 6 5 7 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]


As for your joseki sequence. My understanding is that 3-4 attach against this 4-4 knight enclosure is usually bad, and that's why the 2nd line approaches are more common, and post-AI just the regular knight approach not being scared of kick and pincer. Hane outside is a strong white answer, and the small life for black will also attract disdain from me :) It's typically a sequence you want to use when white ALREADY has an extension on the lower side, hopefully closer than k3 for inefficiency, in which case you couldn't do a better sequence for a less restricted settling so begrudgingly accept this small life.

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 Post subject: Re: Question about 4-4 Small Knight Joseki
Post #4 Posted: Tue May 14, 2019 11:40 pm 
Lives in sente

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Dealing with the 4-4 small knight enclosure?

You dont, you play elsewhere. ;-)

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