Life In 19x19

I was reviewing a game today and suddenly KataGo came up with a crazy move. I'll show the situation before the move, then progressively include tips

Click Here To Show Diagram Code

[go]$$W White to move
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X O O O X X . . . . . . . . . . |
$$ | . . X O O X O O X X X O . . O X . . . |
$$ | . . X O . X . O O O X O . . O , X . . |
$$ | . . . O X X X O . . X . . . . . . . . |
$$ | . . X O X O . X X . X O O . O X X . . |
$$ | . . X X O O X X O X X . . X . O . . . |
$$ | . . . . . . X . O O X O O . . . O . . |
$$ | . . . . . O . . O . O . . . . . . . . |
$$ | . . . , . . . . . O . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . . X . . . . . . . . . O . . . |
$$ | . . . O . . . . . X . . . . . O . . . |
$$ | . . . . . X . . . . . . X . . X O . . |
$$ | . . . O . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Describing the situation:
Describing the problem:
What I did in the game, plus final hint

Ohh this shape looks too familiar,once you solved a similar problem you see it everywhere at first glance

This?

jlt found it and apparently it's a kind of AI cliché already - I'm amazed!

Knotwilg wrote:jlt found it and apparently it's a kind of AI cliché already - I'm amazed!

Don't know about AI cliche, but I think you see this sort of thing in problem books every now and then. I spotted the move too - I did not spot KataGo's continuation, however. The complications have really only started

It's not quite the same thing but I just happen to have this game on my desk as I write. The move was by a young Go Seigen, and is considered so unremarkable it did not even merit a comment.

I have seen this sort of moves many times in real games, and there too it has often been uncommented.

I suggest the following remarks apply:

1. It is a move of a kind you will see a lot of if you replay pro games (as per pro advice) rather than do lots of tsumego (as per amateur obsession).
2. You will see it very occasionally in tsumego problems but rather more often in tesuji colllections (which are, ironically, rarer), as it is a tactical contact-fighting move rather than a killer move. But if you replay lots of pro games you will realise it is a fairly common suji move rather than a tesuji, hence the usual lack of commentary.
3. The second line may the "line of defeat" but it is also often the line for (te)suji, and Sakata above all taught us that. His nickname of Razor came from slicing jugulars on the second line.

What I am saying overall is that this is a frog-in-the-well situation. Said Kermit thinks the sky consists only of the blue circle he can see. (Sorry to be a wee bit Miss Piggy-ish about this.)

Thx John. Yes, the "belly attachment" is a rather common line of play (suji). In the problem I posted, the belly is one line bigger, which makes a difference for me in spotting the move.

I can fathom this is a piece of cake for a pro. So it's not an "AI move" just a move that I happened to discover that way. I'm a little skeptical of the triviality with which it is met but I guess I should replay more pro games so that I too can find this move with the blink of an eye.

Alright, I found the problem I was remembering. Graded Go Problems for Dan Players Volume 5, problem 154.

Click Here To Show Diagram Code

[go]$$Bc19
$$-------------------------+
$$ . . . . . . . . . . . . |
$$ . . . . . . . . O O X X |
$$ . . X . . . O O X X O . |
$$ . . . . O X X X X O O . |
$$ . . X . . . O O O . X . |
$$ . . . . . . . X . X . . |
$$ . . . . . . . . . . . . |
$$ . . . . . . . . . . . . |[/go]

I think the theme is quite similar.

Click Here To Show Diagram Code

[go]$$B
$$-------------------------+
$$ . . . . . . . . . . . . |
$$ . . . . . . 1 5 O O X X |
$$ . . X . . 2 O O X X O . |
$$ . . . . O X X X X O O . |
$$ . . X . . 3 O O O 4 X . |
$$ . . . . . . . X . X . . |
$$ . . . . . . . . . . . . |
$$ . . . . . . . . . . . . |[/go]

This?

Knotwilg wrote:

$$B
$$-------------------------+
$$ . . . . . . . . . . . . |
$$ . . . . . . 1 5 O O X X |
$$ . . X . . 2 O O X X O . |
$$ . . . . O X X X X O O . |
$$ . . X . . 3 O O O 4 X . |
$$ . . . . . . . X . X . . |
$$ . . . . . . . . . . . . |
$$ . . . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B
$$-------------------------+
$$ . . . . . . . . . . . . |
$$ . . . . . . 1 5 O O X X |
$$ . . X . . 2 O O X X O . |
$$ . . . . O X X X X O O . |
$$ . . X . . 3 O O O 4 X . |
$$ . . . . . . . X . X . . |
$$ . . . . . . . . . . . . |
$$ . . . . . . . . . . . . |[/go]

This?

Yes, that's one possibility. and are essentially miai for Black.

But…

Harleqin wrote:But…

Look for a

More analysis at

https://senseis.xmp.net/?BellyAttachmentLadderBreaker

Harleqin wrote:But…

Can Black maybe counter like this?

$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X O O O X X . . . . . . . . . . |
$$ | . . X O O X O O X X X O . . O X . . . |
$$ | . . X O . X . O O O X O . . O , X . . |
$$ | . . . O X X X O . . X . . . . . . . . |
$$ | . . X O X O . X X . X O O . O X X . . |
$$ | . 1 X X O O X X O X X . . X . O . . . |
$$ | . . 2 . . . X . O O X O O . . . O . . |
$$ | . . . . . O . . O . O . . . . . . . . |
$$ | . . . , . . . . . O . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . . X . . . . . . . . . O . . . |
$$ | . . . O . . . . . X . . . . . O . . . |
$$ | . . . . . X . . . . . . X . . X O . . |
$$ | . . . O . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X O O O X X . . . . . . . . . . |
$$ | . . X O O X O O X X X O . . O X . . . |
$$ | . . X O . X . O O O X O . . O , X . . |
$$ | . . . O X X X O . . X . . . . . . . . |
$$ | . . X O X O . X X . X O O . O X X . . |
$$ | . 1 X X O O X X O X X . . X . O . . . |
$$ | . . 2 . . . X . O O X O O . . . O . . |
$$ | . . . . . O . . O . O . . . . . . . . |
$$ | . . . , . . . . . O . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . . X . . . . . . . . . O . . . |
$$ | . . . O . . . . . X . . . . . O . . . |
$$ | . . . . . X . . . . . . X . . X O . . |
$$ | . . . O . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

No, because...

Order of moves matters: