Life In 19x19

Posted: **Thu Mar 05, 2020 4:03 pm**

The following position almost appeared in a game I played on OGS:

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Where would you play here as black? AI analysis is also welcome!

The OGS AI suggested an interesting move that wasn't on my radar at all:

An intriguing move. But does it acutally work, i.e. can one trust the OGS AI in this case?
The AI continuation is the following:

How do you like this result for black?
Regardless, I will try to look for such cheeky moves as the one shown here in my future games.

Posted: **Thu Mar 05, 2020 5:49 pm**

Click Here To Show Diagram Code: [go]$$Bc My first impulse $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O . 1 . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

It seems to me that sacrificing the corner is a good plan for Black. White is too weak on the bottom side not to have to spend a play or two to capture the three Black stones. The corner may even become ko or even seki. Also, if Black lives in the corner but White gets stronger on the bottom side, then Black's stones in the center may become floating.

Click Here To Show Diagram Code: [go]$$Bc On second thought $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . 1 X , . . . . . , . . . . . X . . . | $$ | . . X O O . 3 . . . . . . . . . . . . | $$ | . a . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

On second thought,

reduces the dame of White's three stones by one and threatens to play at a and live or at least make things difficult for White. After playing around a bit, the exchange

-

before playing

looks like an improvement over just playing

.

Click Here To Show Diagram Code: [go]$$Bc Who'd a thunk it? $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O . . . . . . . . . . . . . . | $$ | . . . . . 1 . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

is an interesting play. It attacks White, and, as we have seen, may even result in saving the Black corner stones.

It would not surprise me if all three of these plays are playable.

Posted: **Thu Mar 05, 2020 6:40 pm**

My first thought was to check if black can live inside with some move like this:

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O . . . . . . . . . . . . . . | $$ | . B . C . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

But it's clear that it doesn't work after white's descent.

Next thought is to hold black in:

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O . B . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

and I wondered to myself if that was sente. Or if not, if something like this is working:

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O O X X . X . . . . . . . . . . . . | $$ | . O X O O X . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . X . . . | $$ | . . X O O B . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

But then I got tired of trying to read, and just looked at Bill's answer. I hadn't thought about B4 potentially being sente - I just assumed white could ignore it, since I didn't read a clean capture.

Life In 19x19

What is your next move? or Can I trust the OGS bot?

What is your next move? or Can I trust the OGS bot?

Re: What is your next move? or Can I trust the OGS bot?

Re: What is your next move? or Can I trust the OGS bot?