John Fairbairn wrote:
Consider that lightvector referred to the surrounding-move line as creating a moyo. If I were bored I might quibble and say that it's now a jimoyo rather than a moyo, and if you insisted it was a moyo nevertheless, I'd ask about what O highlights: how then does White use his moyo? (The answer, of course, is that he has already used it to make a jimoyo - a territorial framework as opposed to a framework, which is by no means a bad thing, but recognising that does have implications for understanding the dynamism of the game as a whole.)
Bill Spight wrote:
I think that the distinction between a moyo (framework) and a jimoyo (territorial framework) is significant. In this game Rin decided to protect the corner rather than make a jimoyo. Elf disagrees, and, I suspect, Jowa and other 19th century lights would have, as well, if they were to take komi into account. I think that the bots are telling us that jimoyo are not overconcentrated. By contrast, they do not value early moyo highly.
Knotwilg wrote: A perennial difference between amateurs and professionals, which is echo'd by AI, is that amateurs will much rather fall in love with moyos like the one in Elf's line. Look at that grand area! Professionals care about thickness, territory, efficient shape ... like AIs do.
I agree the distinction between a moyo and jimoyo is important, and so don't agree with "fall in love with moyos like the one in Elf's line". I think it's more common for weak amateurs, particularly Tamekiya fanboys, to like the sort of loose moyo that bots and most pros tend to avoid these days because cutting them down to size through invasion/reduction is too easy. It's the patience to play the sort of consolidating/honte kakoi seen here (which I think bots particularly value as prophylaxis against opponent gaining in sente with effective reductions) that is lacking in weaker players. I wouldn't even say pros do it right an amateurs wrong, the pro did it wrong against PhoenixGo I linked above. I think I've heard via John / Charles Matthews that Seongjune Kim (Korean amateur 6d who lived in Cambridge before my time) said one of the key ideas that got him from 4 to 5 or 5 to 6 dan was essentially kakoi.
Re: Opening problems for AI: Problem 6
Posted: Thu Jun 18, 2020 3:15 am
by Bill Spight
Uberdude wrote:
Bill Spight wrote:
I think that a lot of humans would choose the one space pincer, which Elf prefers by 22½%. At first blush it appears to go against the proverb not to make territory out of thickness.
secures the bottom left corner — well, almost. makes a base, which attacks. is joseki, but Elf regards it as losing 20% to invading the bottom left corner at a.
Sure, it also/primarily functions as an attack on the lower group, but for what profit? It only makes a piddly little overconcentrated territory. White does also have the corner profit too, though that's not solid yet.
"Don't make territory with thickness" should really be "Don't make inefficient territory with thickness", just a specialisation of the uber-proverb that pretty much covers all of Go "don't be inefficient".
Well, Rin Kaiho was already in his prime at the time, and surely judged the value of this attack highly. Speaking for myself, not Rin, having inculcated the dictum to use thickness for attack, not territory, early in my go playing days, I also would have played as in this diagram. It was only much later, after observing 19th century masters using thickness to make jimoyo that I might have played the pincer.
Re: Opening problems for AI: Problem 6
Posted: Sun Jul 26, 2020 12:20 am
by iopq
fat Katago thinks black shouldn't hane underneath in the 3-3 variation after pincer because black prefers getting the left side of the corner instead of the bottom
Screenshot from 2020-07-26 15-07-14.png (714.94 KiB) Viewed 15018 times
You can force out the sequence to see KataGo favors black here
Screenshot from 2020-07-26 15-11-28.png (790.83 KiB) Viewed 15018 times
The other variation is slightly better for white (at 7.5 komi, I didn't bother to change it)
Screenshot from 2020-07-26 15-15-57.png (871.67 KiB) Viewed 15018 times
Although point-wise it's +0.6 in either case, so this might be just winrate estimation error in such a close case
Re: Opening problems for AI: Problem 6
Posted: Sun Jul 26, 2020 3:05 am
by Gomoto
Fat Kata black F5 line is not considered yet in this thread
bill6.JPG (143.79 KiB) Viewed 14996 times
Re: Opening problems for AI: Problem 6
Posted: Sun Jul 26, 2020 3:24 am
by Gomoto
I was just also interested in FatKata's view on this alternative board
bill6alt1.JPG (143.61 KiB) Viewed 14990 times
Re: Opening problems for AI: Problem 6
Posted: Fri Jun 04, 2021 9:56 am
by dhu163
Speculatively:
Current position:
1. All groups very alive except for D4 which is already behind enemy lines (E9 reinforces), F3 unsettled. No-one has big potential. Right is B's development but not easy, perhaps Q9? Overall obviously W needs to settle D4.
2. D3 solid but still C5 problem. E3 F4 D6 seems suicidal as the 3-3 invasion is still a problem and now W is well behind enemy lines. Sometimes E3 F4 F2 is an option. E2 comes to mind as an active move.
3. H3 comes to mind as good shape to balance defending D4, attacking B's weak group and building lower side (W has the biggest wall of the game on the lower right). I envisage H3 D2 F4 (good for W), H3 H4 J4 G4 E2 (good for W), H3 C3 D3 D2 E2 C2 F2 B5 C5 B6 ? (seems good enough for W?)
4. Q2 comes to mind but as it is gote, probably for quite a bit later.
5. Overall can W get away with E3 F4 E6?
Opp to play:
1. C3, try to live in sente by threatening to cut off C7, then activate F3 to severe attack W or destroy lower side.
Past:
1. B's play is slightly slow all over the board with E9, P17, R3. As W I would rather P8 be placed elsewhere: best would be lower left corner but O16 would be nice too. Seems even enough but I slightly prefer W.
Check:
1. seems like I got it right this time. 36 at J6 eh! I was thinking about F8.
2. re: post 3, I did consider blocking the other side too. In mine and Elf's variation, B has solidly connected and made life with everything, so the C12 aji is greatly mitigated. B also still has aji with the lone stone. In the first diagram, G8 comes to mind for W later as a way to grow the lower side and threaten C12 aji slowly, perhaps by playing F10.
secures the bottom left corner — well, almost. 
makes a base, which 
attacks. 
is joseki, but Elf regards it as losing 20% to invading the bottom left corner at a.