Opening problems for AI: Problem 37

For lessons, as well as threads about specific moves, and anything else worth studying.
Post Reply
Bill Spight
Honinbo
Posts: 10905
Joined: Wed Apr 21, 2010 1:24 pm
Has thanked: 3651 times
Been thanked: 3373 times

Opening problems for AI: Problem 37

Post by Bill Spight »

Yet another ancient game. Assume komi, as always. :)

White to play.
Click Here To Show Diagram Code
[go]$$Wcm20 White to play.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . a X . . |
$$ | . . O X X X . . . , . . . . . , b . . |
$$ | . . O X O . . . . . . X . . . O . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
White's next play was in the bottom right corner. Which is better, the jump attachment at a or the kick at b?

By Elf's reckoning one is better by 19%!

Enjoy! :D
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.
Top
Bill Spight
Honinbo
Posts: 10905
Joined: Wed Apr 21, 2010 1:24 pm
Has thanked: 3651 times
Been thanked: 3373 times

Re: Opening problems for AI: Problem 37

Post by Bill Spight »

The game is GoGoD 1620-00-00as, Nakamura Doseki (W) vs. Rigen.
Click Here To Show Diagram Code
[go]$$Wcm20 Game record: Attach and extend
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . 2 . . . |
$$ | . . . O . . . . . . . . . . 3 1 X . . |
$$ | . . O X X X . . . , . . . . . , 4 . . |
$$ | . . O X O . . . . . . X . . . O 5 . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Doseki played the jump attachment, and the next few moves were predictable. White makes easy sabaki. It is not easy to tell that this is a blunder or near blunder for White. Instead of :b21: Elf prefers :b23: by 3%, which is within Elf's margin of error.
Click Here To Show Diagram Code
[go]$$Wcm20 Mainline variation for :b21:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . 8 . . . . |
$$ | . . . , . . . . . , . . . . 7 , X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . 6 . . |
$$ | . . O . . . . . . . . . . . . 4 . . . |
$$ | . . . O . . . . . . . . . . . 1 X . . |
$$ | . . O X X X . . . , . . . . . 3 2 . . |
$$ | . . O X O . . . . . . X . . . O 5 . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
There is not a lot of difference between the two. After both sides have been strengthened in the bottom right corner, :w26: approaches the top right corner and :b27: attaches underneath. The continuation is of some interest.
Click Here To Show Diagram Code
[go]$$Wcm28 Mainline variation for :b21:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . 8 6 X 2 . . . |
$$ | . . . , . . . . . , . . 7 5 O 1 X 4 . |
$$ | . . X . . . . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 9 0 . . |
$$ | . . X O . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . O . . . . . . . . . . . O X . . |
$$ | . . O X X X . . . , . . . . . O X . . |
$$ | . . O X O . . . . . . X . . . O O . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Instead of the usual hane, White plays a nadare and makes a strong wall. Then :w36: comes back and makes a shape play against Black in the bottom right corner. :b37: crawls underneath.

Top choice: The kick
Click Here To Show Diagram Code
[go]$$Wcm20 Kick joseki
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , c a . . . , . . . b . , X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . .. . . |
$$ | . . . O . . . . . . . . . . . 2 X . . |
$$ | . . O X X X . . . , . . . . d , 1 . . |
$$ | . . O X O . . . . . . X . 3 e O . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
White plays the kick and then secures the corner with a one space extension. The bots are teaching us a new appreciation of the kick in the corner. This way White has more territory in the corner and the 2 Black kicked stones are not strong, but Black has sente. Black a - d are all playable, within 1½% winrate of each other. (If Black d, White e.)
Click Here To Show Diagram Code
[go]$$Bcm23 Mainline, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 7 O 6 . . . . . . . . . . . . . . |
$$ | . . 5 , . 1 . . . , . . . . . , X . . |
$$ | . . X 2 4 . . . . . . . . . . . . . . |
$$ | . . . 3 8 . . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . .. . . |
$$ | . . . O . . . . . . . . . . . X X . . |
$$ | . . O X X X . . . , . . . . . , O . . |
$$ | . . O X O . . . . . . X . O . O . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
:b23: plays the taisha in the top left corner and makes secure territory there with this joseki.

Again, this is a question of judgement. The kick joseki in the bottom right corner is one of the bots' favorites.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.
Top
User avatar
Harleqin
Lives in sente
Posts: 921
Joined: Sat Mar 06, 2010 10:31 am
Rank: German 2 dan
GD Posts: 0
Has thanked: 401 times
Been thanked: 164 times

Re: Opening problems for AI: Problem 37

Post by Harleqin »

Click Here To Show Diagram Code
[go]$$Bcm23 Mainline, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 7 O 6 . . . . . . . . . . . . . . |
$$ | . . 5 , . 1 . . . , . . . . . , X . . |
$$ | . . X 2 4 . . . . . . . . . . . . . . |
$$ | . . . 3 8 . . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . .. . . |
$$ | . . . O . . . . . . . . . . . X X . . |
$$ | . . O X X X . . . , . . . . . , O . . |
$$ | . . O X O . . . . . . X . O . O . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
:b23: plays the taisha in the top left corner and makes secure territory there with this joseki.

Again, this is a question of judgement. The kick joseki in the bottom right corner is one of the bots' favorites.
I am a bit surprised. I was taught that that thing in the upper left is usually bad for black, because he has effectively peeped the bamboo joint twice.

On the other hand, looking at it, he got quite some territory out of it, and the funny peep stone on the outside still has 4 liberties, so the bamboo peep heuristic is apparently outweighed by other aspects here. Maybe group tax would punish black's disconnection more.
A good system naturally covers all corner cases without further effort.
Top
dhu163
Lives in gote
Posts: 474
Joined: Tue Jan 05, 2016 6:36 am
Rank: UK 2d Dec15
GD Posts: 0
KGS: mathmo 4d
IGS: mathmo 4d
Has thanked: 62 times
Been thanked: 278 times

Re: Opening problems for AI: Problem 37

Post by dhu163 »

Speculatively:
Current position:
1. This position is quite unusual. Both are quite thick in the lower left so they want to expand.
2. In the lower right S4 is very standard and I wouldn't really think of Q5. In the standard variation, M3 is reasonably placed for O3. Normally W is giving B eyespace for no particular reason as W isn't even 100% alive afterwards.
3. So S4 is standard to live as W is in trouble otherwise. The centre takes B another move to seal so even though it is big, I don't think W needs to worry yet.

Opp to play
1. S2 is tempting even though risky. Perhaps W will play O3 after which maybe B can continue M5. P4 also seems possible but W seems to live reasonably. Hmm, but perhaps B can just respond?

Past:
1. In the lower left, W deviated from joseki, so I assume it is better for B. Basically, B played a split shape to attack W and W didn't want to be cramped, so gave up a stone. However, B gets thick on a side where B has just presumably played a move to continue. Though it isn't great shape there.
2. B is slightly open on the lower side and the centre, so it doesn't seem easy, but B already has a stone on the left too. And W is weak at Q3.

Check:
1. I didn't expect :b21: so that was interesting. A 12% drop is not so big as it sounds during fighting so the jump attachment seems not that bad.
Top
Post Reply

Return to “Study Group”