Life In 19x19 :: How is your positional judgement?

Personnally, I'm unable to say who's better here, so I defer to our Silicium Overlords :

Katago prefer black, giving him around 73% winrate and +11pts (7.5 komi)

One thing it see is that the cut at F9 is not a real problem for black. Black can settle on the side with a push at D10, and if white cut, black can push. Here is what Katago would play if White cut for :w30:

(each move played on lizzie, with over 10k playouts) :

Click Here To Show Diagram Code: [go]$$Wcm30 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . . . . . . . . . . . . . . | $$ | . . O . O X 7 . . , . . . . . , . . . | $$ | . . . X X 1 3 6 . . . . . . . . . . . | $$ | . . . . . 2 4 5 9 . . . . . . . . . . | $$ | . X X . . . . 8 0 . . . . . . . . . . | $$ | . O . X . . . . . . . . . . . . . . . | $$ | . O . X O O . O . . . . . . . . . . . | $$ | . . O O X . . . O , . . . . . X . . . | $$ | . O . . X . X . . . . . . . . . . . . | $$ | . O X X . . . . X . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm40 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 7 . . . . . . . . . . . . . . . . | $$ | . 8 6 5 O . . . . . . . . . . . . . . | $$ | . . O 4 O X O 3 . , . . . . . , . . . | $$ | . . . X X O O X . . . . . . . . . . . | $$ | . . . . 2 X X O O . . . . . . . . . . | $$ | . X X . 1 . . X X . . . . . . . . . . | $$ | . O . X . . . . . . . . . . . . . . . | $$ | . O . X O O . O . . . . . . . . . . . | $$ | . . O O X . . . O , . . . . . X . . . | $$ | . O . . X . X . . . . . . . . . . . . | $$ | . O X X . . . . X . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This explain Katago move for white :

Click Here To Show Diagram Code: [go]$$Wcm30 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . O . . . . . . . . . . . . . . | $$ | . . O . O X . . . , . . . . . , . . . | $$ | . . . X X . . . . . . . . . . . . . . | $$ | . . . . . . . 4 . . . . . . . . . . . | $$ | . X X . . . . . . . . . . . . . . . . | $$ | . O . X . . 2 . . . . . . . . . . . . | $$ | . O . X O O 3 O . . . . . . . . . . . | $$ | . . O O X . . . O , . 5 . . . X . . . | $$ | . O . . X . X . . . . . . . . . . . . | $$ | . O X X . . . . X . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I think I'm 0/2 on the ones I've posted responses so far - I didn't know that the attach underneath was unfavored by the AI! And while I did see the tewari-ish argument Uberdude suggested when I liked the color with the sides, I thought that the jump in the top left corner activated the weakness significantly more than it did. It's fun to play out the positions that I like but the AI doesn't against the AI - shows me how it converts positions I would find uncomfortable to positions I would find winning.
Anyway, time to try to redeem myself. My first instinct is white, because I really like having active influence in the opening. On second consideration, I see the merits of black's position, where we can expect maybe 12 points from the bottom, maybe 10 points from each of the top two corners, and the cutting aji around K5 is really annoying for white. So if my investigation of the present board state is inconclusive, I need to look into either the future or the past. Let's start with the future; below I show my 5 candidate moves from W's next move.

Click Here To Show Diagram Code: [go]$$Wcm27 Which should white play? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . X . . . . . | $$ | . . X , . O . . . , . . . . . S X . . | $$ | . . . . . . . . . . . . . . S . . . . | $$ | . . . . . . . . . . . . . . . . S . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . M . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . S O S X O . . . . . . | $$ | . . . O . . . . O X O O X O O , O O . | $$ | . . . . . . . . . X X . X X . . X . . | $$ | . . . . . . . . . . X . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

My first instinct was to fix the weaknesses around K5 with a full move, but on my read of B's best local move, it doesn't seem 100% urgent (still quite urgent though). The problem is that if B takes sente to approach the play at X, it will be very difficult for W to use the influence. So my second candidate area is to make it difficult for black to take X by starting with either Q16, P15, or R14. The problem is that losing sente would allow black to come back to make the first move somewhere in the K5 area, which gets very painful for white. White can't even really take the left side, and seems to be the struggling side in most variations I'm looking at. So my analysis of the future seems to put black ahead, as there are two areas that are too good for black to take.
So let's look at the past. My guess is that Black 2-space approached a 3-4 white stone in the bottom right corner, and W shoulder hit it.

Click Here To Show Diagram Code: [go]$$Wcm13 Without the fighting on the bottom. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . X . . . . . | $$ | . . X , . O . . . , . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O , O O . | $$ | . . . . . . . . . . . . . X . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Note that there are 7 black stones and 6 white stones on this board. I think AI's would slightly prefer black in this position, as W played a side move, and B got to make pretty decent shape in the bottom right. All the other stones do is have W push over the top of W's bottom. So let's compare the game with a simple variation:

Click Here To Show Diagram Code: [go]$$Wcm13 White pushes B down. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X . . . . . . . . X . . . . . | $$ | . . X , . O . . . , . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . 7 5 3 1 O , O O . | $$ | . . . . . . . . . 8 6 4 2 X . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This variation would be again questionable for W, pushing from behind without great reason. But even this is not actually clearly better for W than the game, where W does basically the same thing but has holes in his shape. The only way the you could claim the game is better is the nearly useless black stone at L2, but I would tend to think that what white owes in the center is worth a move at least. Thus, my analysis of the past seems to concur with my analysis of the future that white's wall is just too thin, and B is ahead.

Author:	Knotwilg [ Thu Oct 17, 2019 4:25 pm ]
Post subject:	Re: How is your positional judgement?
LZ about Bill's continuation of bki's suggestion

Author:	Bill Spight [ Thu Oct 17, 2019 4:40 pm ]
Post subject:	Re: How is your positional judgement?
Knotwilg wrote: LZ about Bill's continuation of bki's suggestion Well, it's not beyond me over the board, but it is Elf's variation. I did not intend to say that Black should play it immediately. You'll have to wait for the later discussion to find out. And I certainly pointed out that Black could play it with sente.

Author:	Bill Spight [ Sun Oct 20, 2019 8:16 am ]
Post subject:	Re: How is your positional judgement?
Game 13. My discussion of Elf's commentary. Lee Changho, 7 dan (W) - Choe Myeonghun, 4 dan 1995-11-13c After Elf gives White a winrate of 88½% (30k playouts). White, Lee Changho, won by resignation. Click Here To Show Diagram Code [go]$$Wcm30 $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . X . . . O . . . . . . . . . . . . \| $$ \| . . . . . . . X X X . . . X . . . . . \| $$ \| . O O O O O X X O O O . . . . X . . . \| $$ \| . X X X . X O O X . . . . O . . . . . \| $$ \| . . . . . X . . O . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Elf's continuation. Click Here To Show Diagram Code [go]$$Bcm31 Elf's mainline continuation $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . 9 . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . 4 . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . X . . . O . . . . . . . . . . . . \| $$ \| . . . . . . . X X X . . . X . . . . . \| $$ \| . O O O O O X X O O O . 7 . . X . . . \| $$ \| . X X X . X O O B 2 . . 8 O . . . . . \| $$ \| . . . . . X 3 1 O . . . . 6 5 . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] - were played in the game, as well as Elf's top choices. - are Elf's mainline variation. Earlier in the game. Click Here To Show Diagram Code [go]$$Bcm17 Boshi loses 17% $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . a . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . X . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . 1 . . . . . \| $$ \| . O O O O O . . . , . . . . . X . . . \| $$ \| . X X X . X . O . . . . . O . . . . . \| $$ \| . . . . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] was totally off Elf's radar. Elf's mainline variation for . Click Here To Show Diagram Code [go]$$Bcm17 Elf's mainline for $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . 1 . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . 0 . . . \| $$ \| . . X . . . . . . . . . . . . . 2 . . \| $$ \| . . . . . . . . . . . . . 5 . . . . . \| $$ \| . O O O O O . . . , . . 4 3 . X 9 . . \| $$ \| . X X X . X . O . . . . . O 8 6 7 . . \| $$ \| . . . . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] With a winrate estimate of 58% (27.7k playouts), is an example of the importance of occupying the last open corner. makes a double approach, leading to a typical joseki. Click Here To Show Diagram Code [go]$$Bcm27 Elf's mainline for , continued $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . X . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . 1 . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . 3 . . . . \| $$ \| . . . . . . . . . . . . . 2 4 O . . . \| $$ \| . . X . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . X . . . 5 . \| $$ \| . O O O O O . . . , . . O X . X X . . \| $$ \| . X X X . X . O . . . . . O O O X . . \| $$ \| . . . . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Game continuation. Click Here To Show Diagram Code [go]$$Wcm18 loses 15½% $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . 1 . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . X . . . . . . . . . . . . . . . . \| $$ \| . . . . . . a . . . . . . X . . . . . \| $$ \| . O O O O O 2 4 . , . . . . . X . . . \| $$ \| . X X X . X 3 O . . . . . O . . . . . \| $$ \| . . . . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] loses 15½% by comparison with a (30.4k playouts). Click Here To Show Diagram Code [go]$$Bcm21 Elf's mainline variation for $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . 6 . . . . . . . . . . . . . . \| $$ \| . . B . . . . 7 . . . . . . . . . . . \| $$ \| . . . . . . 1 . . 9 8 . . X . . . . . \| $$ \| . O O O O O X . 2 , 4 5 . . . X . . . \| $$ \| . X X X . X O O . . . 3 . W . . . . . \| $$ \| . . . . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] After pushes out with a kosumi, then pincers the stone in the bottom right. White presses from the outside and then attacks the stone and Black pushes into the center. Click Here To Show Diagram Code [go]$$Bcm23 Elf's mainline continuation after $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . 0 . 8 . . . . . . . . . . . . . \| $$ \| . . B . . 9 1 . 3 . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . X . . . . . \| $$ \| 6 O O O O O X X W , . . . . . X . . . \| $$ \| 4 X X X . X O O . 2 . . . O . . . . . \| $$ \| 5 . 7 . . X . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] indicates :w22; in the actual game. The rest is Elf's mainline variation. jumps out into the center, then makes a hanging connection. After makes a table shape, White plays hane and connect with sente against the corner. Then White encloses the stone. Game continuation. Click Here To Show Diagram Code [go]$$Bcm23 The cut, :b29, loses 11½% $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . X . . . 4 . . . . . . . . . . . . \| $$ \| . . . . . . . 5 1 3 a . . X . . . . . \| $$ \| . O O O O O X X O 2 6 . . . . X . . . \| $$ \| . X X X . X O O 7 . . . . O . . . . . \| $$ \| . . . . . X . . 8 . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] forces to connect with bad shape. loses 13½% by comparion with the fifth line push at a (61.9k playouts). Elf's mainline variation for Click Here To Show Diagram Code [go]$$Bcm29 Elf's mainline for $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . 7 . . . . . . . . . . . . . \| $$ \| . . . O . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . 8 . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . , . . . \| $$ \| . . . . 9 . . . . . . . . . . . . . . \| $$ \| . . O . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . 4 B . 3 . O . . . . . . . . . . . . \| $$ \| . . . . . . . X X X 1 5 . X . . . . . \| $$ \| . O O O O O X X O O O 2 . . . X . . . \| $$ \| . X X X . X O O . . . . . O . . . . . \| $$ \| . . . . . X . . . . . . . . . 6 . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] presses along the 5th line with sente and then makes a one space jump from the stone, also with sente. connects along the fifth line with sente, and later makes a two space jump into the center.

Author:	Bill Spight [ Sun Oct 20, 2019 9:15 am ]
Post subject:	Re: How is your positional judgement?
Game 15 After Elf estimates the winrate for one player as 94½% (24k playouts). Which player is it? Click Here To Show Diagram Code [go]$$Bcm29 White to play $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . O . . . . . . . . . . . . . . \| $$ \| . . O , O X . . . , . . . . . , . . . \| $$ \| . . . X X . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . X X . . . . . . . . . . . . . . . . \| $$ \| . O . X . . . . . . . . . . . . . . . \| $$ \| . O . X O O . O . . . . . . . . . . . \| $$ \| . . O O X . . . O , . . . . . X . . . \| $$ \| . O . . X . X . . . . . . . . . . . . \| $$ \| . O X X . . . . X . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Enjoy!

Author:	Kirby [ Sun Oct 20, 2019 10:16 am ]
Post subject:	Re: How is your positional judgement?
I like black; black's group on the left seems in better shape than white's floating group.

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

How is your positional judgement? http://lifein19x19.com/viewtopic.php?f=15&t=16909	Page 6 of 7

Author:	Knotwilg [ Sun Oct 20, 2019 4:38 pm ]
Post subject:	Re: How is your positional judgement?
Well, after game 13, what do I know, but ... White can press down Black on the lower side and cut off the stone on the left. On the other hand, 5 stones are not doing a lot in the lower left corner. I go for White but actually I have no idea here.

Author:	bernds [ Sun Oct 20, 2019 6:37 pm ]
Post subject:	Re: How is your positional judgement?
Bill Spight wrote: Game 15 After Elf estimates the winrate for one player as 94½% (24k playouts). Which player is it? I'm really not sure. With boards like this, with one side played out and the other untouched, I sometimes try to ask myself whether White got enough out of his two stone advantage on that side. Looking just at secure territory I'd say no, but then again not everything is settled. White has sente, and the fighting might lead to the top left solidifying further. On the other hand, White also has a weak group. I think I'd rather have Black, but not with 94% certainty.

Author:	Tryss [ Mon Oct 21, 2019 1:04 am ]
Post subject:	Re: How is your positional judgement?
Personnally, I'm unable to say who's better here, so I defer to our Silicium Overlords : Katago prefer black, giving him around 73% winrate and +11pts (7.5 komi) One thing it see is that the cut at F9 is not a real problem for black. Black can settle on the side with a push at D10, and if white cut, black can push. Here is what Katago would play if White cut for (each move played on lizzie, with over 10k playouts) : Click Here To Show Diagram Code [go]$$Wcm30 $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . O . . . . . . . . . . . . . . \| $$ \| . . O . O X 7 . . , . . . . . , . . . \| $$ \| . . . X X 1 3 6 . . . . . . . . . . . \| $$ \| . . . . . 2 4 5 9 . . . . . . . . . . \| $$ \| . X X . . . . 8 0 . . . . . . . . . . \| $$ \| . O . X . . . . . . . . . . . . . . . \| $$ \| . O . X O O . O . . . . . . . . . . . \| $$ \| . . O O X . . . O , . . . . . X . . . \| $$ \| . O . . X . X . . . . . . . . . . . . \| $$ \| . O X X . . . . X . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Click Here To Show Diagram Code [go]$$Wcm40 $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . 7 . . . . . . . . . . . . . . . . \| $$ \| . 8 6 5 O . . . . . . . . . . . . . . \| $$ \| . . O 4 O X O 3 . , . . . . . , . . . \| $$ \| . . . X X O O X . . . . . . . . . . . \| $$ \| . . . . 2 X X O O . . . . . . . . . . \| $$ \| . X X . 1 . . X X . . . . . . . . . . \| $$ \| . O . X . . . . . . . . . . . . . . . \| $$ \| . O . X O O . O . . . . . . . . . . . \| $$ \| . . O O X . . . O , . . . . . X . . . \| $$ \| . O . . X . X . . . . . . . . . . . . \| $$ \| . O X X . . . . X . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] This explain Katago move for white : Click Here To Show Diagram Code [go]$$Wcm30 $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . 1 . . . . . . . . . . . . . . . . \| $$ \| . . . . O . . . . . . . . . . . . . . \| $$ \| . . O . O X . . . , . . . . . , . . . \| $$ \| . . . X X . . . . . . . . . . . . . . \| $$ \| . . . . . . . 4 . . . . . . . . . . . \| $$ \| . X X . . . . . . . . . . . . . . . . \| $$ \| . O . X . . 2 . . . . . . . . . . . . \| $$ \| . O . X O O 3 O . . . . . . . . . . . \| $$ \| . . O O X . . . O , . 5 . . . X . . . \| $$ \| . O . . X . X . . . . . . . . . . . . \| $$ \| . O X X . . . . X . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go]

Author:	Knotwilg [ Mon Oct 21, 2019 2:16 am ]
Post subject:	Re: How is your positional judgement?
LZ/Kata on game 15

Author:	Bill Spight [ Mon Oct 21, 2019 4:38 am ]
Post subject:	Re: How is your positional judgement?
Knotwilg wrote: LZ/Kata on game 15 BTW, this is not the result of an invasion, but of a 3 space high pincer.

Author:	Bill Spight [ Wed Oct 23, 2019 8:17 am ]
Post subject:	Re: How is your positional judgement?
Game 16 After Elf estimates the winrate for one player as 89% (59.6k playouts). Which player is it? Click Here To Show Diagram Code [go]$$Bcm27 White to play. $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X . . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . , X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . O . . . . . . \| $$ \| . . . . . . . . . O . X O . . . . . . \| $$ \| . . . O . . . . O X O O X O O , O O . \| $$ \| . . . . . . . . . X X . X X . . X . . \| $$ \| . . . . . . . . . . X . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Enjoy!

Author:	bernds [ Wed Oct 23, 2019 8:58 am ]
Post subject:	Re: How is your positional judgement?
Bill Spight wrote: Game 16 After Elf estimates the winrate for one player as 89% (59.6k playouts). Which player is it? I'd take Black. This time I'm more than 89% certain, which probably means I'm wrong. But White's moyo on the right side doesn't look all that impressive to me, and yet it's a one-basket situation. Black has two shimaris plus territory at the bottom, which looks superior to me.

Author:	Uberdude [ Wed Oct 23, 2019 9:14 am ]
Post subject:	Re: How is your positional judgement?
White, because black's circled empty triangle connection is dumb and becomes really inefficient if he takes the 2 stones. (And the 2nd line square-marked slide is already inefficient). (W 27 just some random move for example). W J4 atari is so nice free kikashi, black presumably played L3 but that was a mistake. In actual practice maybe white plays 28 as k6 nobi but the point remains the same that eventually black will need to capture and the marked stone is retarded. There are some other moves Elf probably doesn't like, such as white's s4 descent in reply to attach being somewhat generous, right side move, probably several mistakes in this distant approach joseki, but they are minor compared to these 2 inefficient black stones. Click Here To Show Diagram Code [go]$$Wcm27 White to play. $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X 1 . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . , X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . 3 . O . . . . . . \| $$ \| . . . . . . . . . O 2 X O . . . . . . \| $$ \| . . . O . . . . O X O O X O O , O O . \| $$ \| . . . . . . . . . B X 4 X X . . X . . \| $$ \| . . . . . . . . . . # . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] P.S. Seeing as there is no tax on making new threads, I think each game should be a new thread because all these interleaved replies are confusing. I don't think having a load of separate threads in the study group subforum is bad.

Author:	Knotwilg [ Wed Oct 23, 2019 9:29 am ]
Post subject:	Re: How is your positional judgement?
I'm increasingly uncomfortable with making a statement. Sometimes the "no territory" argument prevails, other times the "locked up in a corner" aspect wins. Click Here To Show Diagram Code [go]$$W $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X . . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . , X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . 3 5 O . . . . . . \| $$ \| . . . . . . . . 1 O 2 X O . . . . . . \| $$ \| . . . O . . . . O X O O X O O , O O . \| $$ \| . . . . . . . . . X X 4 X X . . X . . \| $$ \| . . . . . . . . a . X . . . . X . b . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] The connection at looks huge. If we assume 2-3-4-5, White's influence should really be superior to Black's territory, even if "bots dislike influence". White's lower left 4-4 benefits from this connection, and together with komi, should match Black's two corner enclosures. The top right likes an extension, but White's already there. Black will probably not go for right away but then a White play here turns his lower side into a liability, with A and B as pressure points. So Black's sente will only be temporary and he also still needs to respond to the shoulder hit at the top. Taking all this into consideration, I go for the "locked up" argument, rather than the "territory" one.

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Author:	Joaz Banbeck [ Wed Oct 23, 2019 9:38 am ]
Post subject:	Re: How is your positional judgement?
Uberdude wrote: ... P.S.... I think each game should be a new thread because all these interleaved replies are confusing. I don't think having a load of separate threads in the study group subforum is bad. I've been thinking the same thing. I could even create a sub-sub-forum especially for the threads. Anyone have opinions on this? ( Especially you, Bill )

Author:	Bill Spight [ Wed Oct 23, 2019 11:13 am ]
Post subject:	Re: How is your positional judgement?
Oh, I like subthreads. Much better organization.

Author:	Bill Spight [ Wed Oct 23, 2019 7:11 pm ]
Post subject:	Re: How is your positional judgement?
I can keep up this pace for a while. I will be happy to start a new topic or subtopic and even organize the existing discussions via copying or linking over time. It is quite possible that others in the future might find these positions and discussions of value. Organizing our discussions would be good for them. Perhaps a good template would be to post the position in the first note of the topic and my disussion, hidden, in the second note.

Author:	TelegraphGo [ Wed Oct 23, 2019 11:41 pm ]
Post subject:	Re: How is your positional judgement?
Before looking at the other responses: I think I'm 0/2 on the ones I've posted responses so far - I didn't know that the attach underneath was unfavored by the AI! And while I did see the tewari-ish argument Uberdude suggested when I liked the color with the sides, I thought that the jump in the top left corner activated the weakness significantly more than it did. It's fun to play out the positions that I like but the AI doesn't against the AI - shows me how it converts positions I would find uncomfortable to positions I would find winning. Anyway, time to try to redeem myself. My first instinct is white, because I really like having active influence in the opening. On second consideration, I see the merits of black's position, where we can expect maybe 12 points from the bottom, maybe 10 points from each of the top two corners, and the cutting aji around K5 is really annoying for white. So if my investigation of the present board state is inconclusive, I need to look into either the future or the past. Let's start with the future; below I show my 5 candidate moves from W's next move. Click Here To Show Diagram Code [go]$$Wcm27 Which should white play? $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X . . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . S X . . \| $$ \| . . . . . . . . . . . . . . S . . . . \| $$ \| . . . . . . . . . . . . . . . . S . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . M . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . O . . . . . . \| $$ \| . . . . . . . . S O S X O . . . . . . \| $$ \| . . . O . . . . O X O O X O O , O O . \| $$ \| . . . . . . . . . X X . X X . . X . . \| $$ \| . . . . . . . . . . X . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] My first instinct was to fix the weaknesses around K5 with a full move, but on my read of B's best local move, it doesn't seem 100% urgent (still quite urgent though). The problem is that if B takes sente to approach the play at X, it will be very difficult for W to use the influence. So my second candidate area is to make it difficult for black to take X by starting with either Q16, P15, or R14. The problem is that losing sente would allow black to come back to make the first move somewhere in the K5 area, which gets very painful for white. White can't even really take the left side, and seems to be the struggling side in most variations I'm looking at. So my analysis of the future seems to put black ahead, as there are two areas that are too good for black to take. So let's look at the past. My guess is that Black 2-space approached a 3-4 white stone in the bottom right corner, and W shoulder hit it. Click Here To Show Diagram Code [go]$$Wcm13 Without the fighting on the bottom. $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X . . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . . X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . . . . . O , O O . \| $$ \| . . . . . . . . . . . . . X . . X . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Note that there are 7 black stones and 6 white stones on this board. I think AI's would slightly prefer black in this position, as W played a side move, and B got to make pretty decent shape in the bottom right. All the other stones do is have W push over the top of W's bottom. So let's compare the game with a simple variation: Click Here To Show Diagram Code [go]$$Wcm13 White pushes B down. $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . X . . . . . . . . X . . . . . \| $$ \| . . X , . O . . . , . . . . . . X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . , . . . . . , . . . . . O . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . O . . . . . . 7 5 3 1 O , O O . \| $$ \| . . . . . . . . . 8 6 4 2 X . . X . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] This variation would be again questionable for W, pushing from behind without great reason. But even this is not actually clearly better for W than the game, where W does basically the same thing but has holes in his shape. The only way the you could claim the game is better is the nearly useless black stone at L2, but I would tend to think that what white owes in the center is worth a move at least. Thus, my analysis of the past seems to concur with my analysis of the future that white's wall is just too thin, and B is ahead. After looking at the other responses: I've never lost a game nor seen someone else lose a game because of committing efficiently to one particular area, so I don't actually agree with the one-basket argument. Uberdude's argument that L2 really is just that bad is tempting, because none of W's stones are so obviously out of place. Admittedly, I don't know just how lopsided Elf likes to evaluate, but my impression is that passing (basically what playing L2 is) would drop you from 50% to maybe 80%. I don't think W has other great advantages, so I'd give an upper bound of W's winrate at around 80% - so knowing that the winrate is 89% makes me want to double down on black. But who knows? I'm getting a feeling I've just gone 0/3

Author:	Knotwilg [ Thu Oct 24, 2019 1:15 am ]
Post subject:	Re: How is your positional judgement?
Bill Spight wrote: I can keep up this pace for a while. I will be happy to start a new topic or subtopic and even organize the existing discussions via copying or linking over time. It is quite possible that others in the future might find these positions and discussions of value. Organizing our discussions would be good for them. Perhaps a good template would be to post the position in the first note of the topic and my disussion, hidden, in the second note. I offer to consolidate on Sensei's Library and link from here. SL is better for reference material I think, while L19 is clearly better for discussion.

Author:	Bill Spight [ Thu Oct 24, 2019 1:33 am ]
Post subject:	Re: How is your positional judgement?
Knotwilg wrote: Bill Spight wrote: I can keep up this pace for a while. I will be happy to start a new topic or subtopic and even organize the existing discussions via copying or linking over time. It is quite possible that others in the future might find these positions and discussions of value. Organizing our discussions would be good for them. Perhaps a good template would be to post the position in the first note of the topic and my disussion, hidden, in the second note. I offer to consolidate on Sensei's Library and link from here. SL is better for reference material I think, while L19 is clearly better for discussion. Thanks. Still, from now on I will start a new topic for each new game. And for myself, I feel that I am benefitting from the discussion here, from the different ideas and perspectives. To find a game all I have to do is find an extreme winrate estimate by Elf. (That was easy for games in the 1950s, because pros had not yet learned how to play with komi. Games from last year, OTOH, feature almost perfect openings.)