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Early Middle Game Question
http://www.lifein19x19.com/viewtopic.php?f=4&t=16154
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Author:  BlindGroup [ Sun Oct 14, 2018 1:53 pm ]
Post subject:  Early Middle Game Question

I recently played a game where it seems that I fundamentally misjudged the game at the start of the middle game. I was playing on Fox, and surprisingly, we got fairly far into the fuseki before the middle game started!

That said, I had to play white on this board.

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


Two questions:

1. When I got to this point in the game, I thought -- Wow! I really got outplayed in the fuseki, but Lizzie seems to think that white is ahead with a 60% chance of winning. Am I just off? My guess is that I am undervaluing the stones at R6 and C6, but to me it seems that I have four reasonably solid groups -- two with very little territory (those on top) and two with the "normal" amount (those on bottom). Black's positions are certainly thinner, but he (a.) has potential to expand them into the center and (b.) I can't really invade them without allowing him to build up in another area.

2. What should white's plan be and specifically, what is the next move? I considered A-F. Lizzie prefers E. The idea being to threaten black's three stone column and use the resulting bulk to attack the group on the left. Is that obviously the right move at this point? I thought about pressing white on the right with something like A, but with the position of the black group on top, it's not clear to me that I can profit from the resulting influence. I also thought about B or C, but it seems too early for those. they just give black a chance to secure the white stones in response. Even if I then play K4, I'm behind on territory. I feel like this is one of those situations where I just don't understand one of the positions on the board. In the game, I decided to try to break up black's position with D, which Lizzie did not like at all.

Author:  dfan [ Sun Oct 14, 2018 2:07 pm ]
Post subject:  Re: Early Middle Game Question

e is certainly the move that leaps out to me.

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

Three groups in a row are weak (to varying degrees). Playing e strengthens your weak group while weakening both of his. It's the kind of move that you dread seeing as Black. I don't know exactly how the fight is going to turn out but I play this sort of move on principle and save my thinking time for the tactics in the fight that follows.

If you are a sector line fan, as I am, your White group used to be inside a Black sector line; now both Black groups are inside White sector lines. That's a huge turnaround.

Author:  Bill Spight [ Sun Oct 14, 2018 2:39 pm ]
Post subject:  Re: Early Middle Game Question

BlindGroup wrote:
I recently played a game where it seems that I fundamentally misjudged the game at the start of the middle game. I was playing on Fox, and surprisingly, we got fairly far into the fuseki before the middle game started!

That said, I had to play white on this board.

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . O . . X . . X . . X . O . . O . . |
$$ | . . . O . . . . . , . . . . . O . X . |
$$ | . . . . . W . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . W . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . a d . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . g . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . e . . . . . . . . . f . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . b . . , . . c . X X X . . |
$$ | . . O O . . . . . . . . . . . O O . . |
$$ | . . . . . O . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]


Two questions:

1. When I got to this point in the game, I thought -- Wow! I really got outplayed in the fuseki, but Lizzie seems to think that white is ahead with a 60% chance of winning. Am I just off? My guess is that I am undervaluing the stones at R6 and C6, but to me it seems that I have four reasonably solid groups -- two with very little territory (those on top) and two with the "normal" amount (those on bottom). Black's positions are certainly thinner, but he (a.) has potential to expand them into the center and (b.) I can't really invade them without allowing him to build up in another area.


Group strength is quite important. BTW, Lizzie's evaluation puts paid to those who think that bots prefer territory.

Quote:
2. What should white's plan be and specifically, what is the next move? I considered A-F. Lizzie prefers E. The idea being to threaten black's three stone column and use the resulting bulk to attack the group on the left. Is that obviously the right move at this point?


It jumps out to me. And, given my inclination to attack at the time, it would have when I was a DDK, as well. ;)

Quote:
I thought about pressing white on the right with something like A, but with the position of the black group on top, it's not clear to me that I can profit from the resulting influence.


My feeling is that White's central stones, marked, reduce Black's potential in the center, as well as supporting Black's attack on the left side. So invading the right seems like the right idea. (OC, the attack on the left side comes first.) Best play probably depends upon the attack on the left side, but f looks like a good place to start. Also consider g as an important option, perhaps as a probe. A successful invasion will probably involve sacrificing some stones.

Quote:
I feel like this is one of those situations where I just don't understand one of the positions on the board. In the game, I decided to try to break up black's position with D, which Lizzie did not like at all.


An invasion of the right side is premature, whether d is the right place to start or not. Black should be able to take sente and strengthen the left side, which could well put him ahead.

P.S. White can invade the top side, as well. :)

Author:  BlindGroup [ Sun Oct 14, 2018 5:38 pm ]
Post subject:  Re: Early Middle Game Question

Just had a chance to try it out at move 60. I'd say it worked well, despite my boneheaded move at 68. Although, I managed to get away with it. I think I may have spent too much time playing on Fox ;-)



Attachments:
2018-10-15 W Fox 1D.sgf [3.63 KiB]
Downloaded 605 times

Author:  dfan [ Sun Oct 14, 2018 6:20 pm ]
Post subject:  Re: Early Middle Game Question

Not that :w60: in your second game is necessarily a bad move, but I think it's a pretty different situation from the first game. This time both Black groups to either side of your single stone are significantly stronger, so you are mostly trying to run rather than to attack.

My first instinct in the area would be something like L4, trying to reduce Black without committing to saving the one stone at O3. I'm not sure you're done attacking Black's group in the upper left, either.

Author:  BlindGroup [ Sun Oct 14, 2018 6:59 pm ]
Post subject:  Re: Early Middle Game Question

dfan wrote:
Not that :w60: in your second game is necessarily a bad move, but I think it's a pretty different situation from the first game. This time both Black groups to either side of your single stone are significantly stronger, so you are mostly trying to run rather than to attack.

My first instinct in the area would be something like L4, trying to reduce Black without committing to saving the one stone at O3. I'm not sure you're done attacking Black's group in the upper left, either.


I get that the position is different. Honestly, I played the move largely because it didn't seem any worse than the other things I considered, and I just to see what would happen. Leela preferred pressing on top with J16, but turned out that she like my move just slightly more. L4 is an interesting idea. I'll have to think about it!

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