Life In 19x19

Posted: **Thu Oct 03, 2019 9:41 am**

Knotwilg wrote:LZ's variations on Position A, with my own comments (she speaks in sequences only)

Interesting that my "bot special" reduction got no first choice votes. Lizzie considered it but gave it only 129 playouts. With so few playouts I would not trust the winrate estimate. What happens when you force the play? (It will inherit the winrate estimate from Lizzie's top reply. That's what the Elf team did when a move got fewer than 500 playouts.

)

Posted: **Fri Oct 04, 2019 3:51 pm**

Position B: my results.

Uberdude had this right. Hane at the head of two stones is "the only move". What got me interested is the fact that this is the only one of problems 1-20 where the book gives follow-up sequences, rather than just "here is the key move". And the bots' follow-ups are quite different from the book's!

Position B is problem 9 from the book. I think for most human players, the bottom right is a very "hot" position. It's hard to imagine ignoring it (although Knotwilg's imagination is clearly better than mine!) and it's hard to imagine playing a single move there followed by tenuki for either player. But the bots see it differently. Here are the three main variations.

Click Here To Show Diagram Code: [go]$$c "These are the standard moves" $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . a 2 . . . . | $$ | . . O . . . . . . . . . . 3 1 O O 6 . | $$ | . . . . . . . . . . . . . . . X X 4 . | $$ | . . . O . . . . . X . . . . . , . 5 . | $$ | . . . . . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This (above) is the recommended follow-up from the book. (But can black get away with the double hane at 'a'? KataGo thinks yes, although the difference in evaluation is minimal.)

Click Here To Show Diagram Code: [go]$$c White can't cut $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 7 . . | $$ | . . . . . . . . . . . . . . a . . . . | $$ | . . O . . . . . . . . . . 3 1 O O . . | $$ | . . . . . . . . . . . . 6 . 2 X X . . | $$ | . . . O . . . . . X . . . . 4 , . . . | $$ | . . . . . X . . . . . . . . 5 X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This is the book sequence to show why

is bad. KataGo prefers 'a' for

.

Click Here To Show Diagram Code: [go]$$c AI alternative $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . 1 O O . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . . O . . . . . X . . . . . , . . . | $$ | . . . . . X . . . . . . . . . X 2 a . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Five out of six bots say white should continue at

(AQ gives this as second choice after the book line.) Then in most cases black replies at 'a', and white's next move is elsewhere. Variations and evaluations:

Posted: **Fri Oct 04, 2019 6:31 pm**

Click Here To Show Diagram Code: [go]$$Bc Two step hane, crawling on the 5th line $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . W . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . 5 4 . . . . | $$ | . . . . . . . . . . . . . 3 2 . . . . | $$ | . . O . . . . . . . . . . a 1 O O . . | $$ | . . . . . . . . . . . . . . b X X . . | $$ | . . . O . . . . . X . . . . . , . . . | $$ | . . . . . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I also expected unanimity for

.

However, I anticipated this as the typical bot sequence.

Before the bot era I, like the book, would have extended to a rather than play the two step hane. Not because of any tactical problem with it, but because

would not only be crawling on the 5th line

, but also would make

look better. Without

looks a little too far from the White wall, such as it is. However, the bots don't seem to mind forcing their opponent to crawl along the 5th line, making territory in the process, they prefer their outside strength on the 6th line, even with a possible cut at a or b. This is one example of why I do not say that the bots are territorial.

Posted: **Sat Oct 05, 2019 2:25 am**

Position C: my results.

Position C is problem 12 from the book. Here the issue is how to reduce white's moyo at the bottom.

Click Here To Show Diagram Code: [go]$$c Position C. Black to play. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . O . . O . . X . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . O . . . . . . . . . . . . . . | $$ | . X X . . . . . . . . . . . . . X . . | $$ | . . . O . . . . . a . . . . . . . . . | $$ | . . X O . . . . c b . . . . . X . . . | $$ | . . X O . . . . . . O . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The book answer is 'a'. But the bots are unanimous: 'b' is better. As far as I can tell, the reason is that 'a' is not forceful enough. The book suggests that if Black 'a' then White 'c'. But the bots say no, white can tenuki and invade the top right. On the other hand, if Black 'b' then the bots recommend that white should answer locally.

Posted: **Sat Oct 05, 2019 2:43 am**

For C, I am surprised that the book play is not the same as that of the bots. There is even a proverb about it.

(I expected that at least one bot might pick the book play, though.

) The bot play lies within only one sector line, but it is from the distant stone on O-03, so arguably it does not count.

Posted: **Sun Oct 06, 2019 2:15 am**

Position D: my results.

Position D is problem 17 from the book. Black needs to defend the bottom left group--but exactly which move is best?

Click Here To Show Diagram Code: [go]$$c Position D. Black to play. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . O . . . O . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . W . . . . . . . . . . . . . . . . | $$ | . a b . . . . . . . . . . . . . . . . | $$ | . c d X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , O . . . . , . . . . . , X . . | $$ | . . . X O . . O . . e . . X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Now I'm sure I've seen the bottom left position as a problem in a book, although I can't remember exactly where, and 'd' was promoted as an example of honte, leaving no weaknesses in the corner and getting ready to pincer

. Indeed 'd' is the book move, but only AQ had it as first choice. All the other bots picked 'a', mostly as the only move examined, except that GX-47 had 'c' as second choice and AQ had 'b' as second choice. Regardless of which move is chosen, white wants to play 'e' pretty soon.

I also searched GoGoD (Spring 1998, with help from Kombilo) for this shape and found 23 hits. Black played 'b' and 'd' 11 times each and 'c' once, with no occurences of the bots' favourite move.

KataGo evaluations and followup moves:

Posted: **Sun Oct 06, 2019 2:53 am**

xela wrote:I also searched GoGoD (Spring 1998, with help from Kombilo) for this shape and found 23 hits. Black played 'b' and 'd' 11 times each and 'c' once, with no occurences of the bots' favourite move.

Human cultural blind spot.

Posted: **Tue Oct 08, 2019 4:29 am**

Position E: my results.

Position E is problem 19 from the book. The key issue is how to deal with white's moyo at the top left -- or is it?

Click Here To Show Diagram Code: [go]$$c Position E. Black to play. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . X . . . . | $$ | . . . , . . O . . X . . . . . , X . . | $$ | . . c b . . . . . . . . . . . . e . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . d . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . O . a . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . X . . . . . , . . . | $$ | . . f . . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The book move is 'a'. The bots generally thought the top right was more interesting: black should play 'd', or if black plays elsewhere then white will play 'e' soon.

'a' was the book move.
'd' was first choice for LZ-242, GX47, KataGo and Ray.
ELF chose 'b'.
AQ chose 'c'.
GX47 threw out 'f' as a close second choice.

KataGo evaluations and followup moves:

Life In 19x19

501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs

Re: 501 Opening Problems and a committee of AIs