Life In 19x19

Posted: **Thu Oct 26, 2023 12:35 pm**

Nice - halfway the analysis I had already forgotten about the non-existence of the confirmation

Posted: **Thu Oct 26, 2023 1:49 pm**

As soon as you have discovered a strange position you can often build a problem where the first move of the solution could be a very strange move. Here it is:

Area counting. Komi 5.5

Click Here To Show Diagram Code: [go]$$B Black to play and win $$ -------------------- $$ |. X . O O X X O . | $$ |O X O . O X X O X | $$ |O X O O O X X O X | $$ |. X O . O X X O . | $$ |X X O O O X X O O | $$ |O O O X X X X X X | $$ |X X X X O O O O O | $$ |X X X X O O X O . | $$ |. X . X O . X X . | $$ --------------------[/go]

I like this kind of problem.

Posted: **Thu Oct 26, 2023 6:25 pm**

Area counting. Komi -6.5 (negative)

Click Here To Show Diagram Code: [go]$$W White to play and win $$ +-------------------+ $$ | . X X X O O X O . | $$ | O X X O . O X O O | $$ | O X X O O O X O . | $$ | . X X O . O X O O | $$ | X X X O O . X X O | $$ | O O O O X X X X X | $$ | X . X X X O O O O | $$ | X X X X O O X O . | $$ | . X . X O . X X . | $$ +-------------------+[/go]

Posted: **Fri Oct 27, 2023 12:37 pm**

dany wrote:Area counting. Komi -6.5 (negative)
$$W White to play and win
$$ +-------------------+
$$ | . X X X O O X O . |
$$ | O X X O . O X O O |
$$ | O X X O O O X O . |
$$ | . X X O . O X O O |
$$ | X X X O O . X X O |
$$ | O O O O X X X X X |
$$ | X . X X X O O O O |
$$ | X X X X O O X O . |
$$ | . X . X O . X X . |
$$ +-------------------+
Click Here To Show Diagram Code
[go]$$W White to play and win $$ +-------------------+ $$ | . X X X O O X O . | $$ | O X X O . O X O O | $$ | O X X O O O X O . | $$ | . X X O . O X O O | $$ | X X X O O . X X O | $$ | O O O O X X X X X | $$ | X . X X X O O O O | $$ | X X X X O O X O . | $$ | . X . X O . X X . | $$ +-------------------+[/go]

Maybe I miss something because it seems simple and in addition I see two solutions.
The point is the following : to win white must capture the black group in the upper left corner. By capturing this group immediatly, white gives black a ko threat and black will capture the white stones in the bottom right corner. It remains only the two dame between the white and black living groups in the center. To win white has only to occupy these two dame which is quite simple: instead of forcing black to begin a ko, white can simply begin herself this ko:

Click Here To Show Diagram Code: [go]$$W White to play and win $$ +-------------------+ $$ | . X X X O O X O . | $$ | O X X O . O X O O | $$ | O X X O O O X O . | $$ | . X X O . O X O O | $$ | X X X O O 3 X X O | $$ | O O O O X X X X X | $$ | X 5 X X X O O O O | $$ | X X X X O O X O 2 | $$ | . X . X O 4 X X 1 | $$ +-------------------+[/go]

I think white can also win by beginning in the upper left corner but the short sequence above is obviously simpler.

Posted: **Fri Oct 27, 2023 6:36 pm**

Gérard TAILLE wrote:As soon as you have discovered a strange position you can often build a problem where the first move of the solution could be a very strange move. Here it is:

Area counting. Komi 5.5
$$B Black to play and win
$$ --------------------
$$ |. X . O O X X O . |
$$ |O X O . O X X O X |
$$ |O X O O O X X O X |
$$ |. X O . O X X O . |
$$ |X X O O O X X O O |
$$ |O O O X X X X X X |
$$ |X X X X O O O O O |
$$ |X X X X O O X O . |
$$ |. X . X O . X X . |
$$ --------------------
Click Here To Show Diagram Code
[go]$$B Black to play and win $$ -------------------- $$ |. X . O O X X O . | $$ |O X O . O X X O X | $$ |O X O O O X X O X | $$ |. X O . O X X O . | $$ |X X O O O X X O O | $$ |O O O X X X X X X | $$ |X X X X O O O O O | $$ |X X X X O O X O . | $$ |. X . X O . X X . | $$ --------------------[/go]
I like this kind of problem.

After finally understanding the point about the rules

, I think this version is very nice!

Posted: **Sun Oct 29, 2023 9:09 am**

ez4u wrote:
Gérard TAILLE wrote:As soon as you have discovered a strange position you can often build a problem where the first move of the solution could be a very strange move. Here it is:

Area counting. Komi 5.5
$$B Black to play and win
$$ --------------------
$$ |. X . O O X X O . |
$$ |O X O . O X X O X |
$$ |O X O O O X X O X |
$$ |. X O . O X X O . |
$$ |X X O O O X X O O |
$$ |O O O X X X X X X |
$$ |X X X X O O O O O |
$$ |X X X X O O X O . |
$$ |. X . X O . X X . |
$$ --------------------
Click Here To Show Diagram Code
[go]$$B Black to play and win $$ -------------------- $$ |. X . O O X X O . | $$ |O X O . O X X O X | $$ |O X O O O X X O X | $$ |. X O . O X X O . | $$ |X X O O O X X O O | $$ |O O O X X X X X X | $$ |X X X X O O O O O | $$ |X X X X O O X O . | $$ |. X . X O . X X . | $$ --------------------[/go]
I like this kind of problem.
After finally understanding the point about the rules , I think this version is very nice!

Thank you ez4u.

BTW, do somebody know a (professionnal) game, played under area counting rules, in which the following scheme appears?

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

This configuration seems very interesting, especially for black, and I would be very interested to see how professionnal can use its potential which spreads all over the board till the very very end of the game.

Posted: **Tue Oct 31, 2023 3:02 am**

Gérard TAILLE wrote:do somebody know a (professionnal) game, played under area counting rules, in which the following scheme appears

This variant may be too specific, but similar unremovable kos, something like the original sending-3-returning-1 might have occurred somewhere, maybe from an ignored threat. But pattern search for such is hard without an exact pattern of outer stones.

Btw, L/D confirmation was mentioned earlier, but the rules issue here is not confirmation itself - it is the local view in it. The pass-for-ko rule of J89 removes ko considerations from hypothetical play. An imaginary confirmation with normal ko (the obvious first step of any analysis) could find that these stones are not capturable without taking (enabling) a loss elsewhere, so they are alive (like bent4 + unremovable threat, or these). The tricky part is top right W 6 stones in first example, where the "loss elsewhere" is subtle and seems hard to recognise formally with a simple enough rule (enabling de-enabling).

Posted: **Tue Oct 31, 2023 12:06 pm**

jann wrote:
Gérard TAILLE wrote:do somebody know a (professionnal) game, played under area counting rules, in which the following scheme appears
This variant may be too specific, but similar unremovable kos, something like the original sending-3-returning-1 might have occurred somewhere, maybe from an ignored threat. But pattern search for such is hard without an exact pattern of outer stones.

Btw, L/D confirmation was mentioned earlier, but the rules issue here is not confirmation itself - it is the local view in it. The pass-for-ko rule of J89 removes ko considerations from hypothetical play. An imaginary confirmation with normal ko (the obvious first step of any analysis) could find that these stones are not capturable without taking (enabling) a loss elsewhere, so they are alive (like bent4 + unremovable threat, or these). The tricky part is top right W 6 stones in first example, where the "loss elsewhere" is subtle and seems hard to recognise formally with a simple enough rule (enabling de-enabling).

Yes Yann, with the position allowing the sending-3-returning-1 you mentionned you can build the same kind of position:

Area counting. Komi 7.5

Click Here To Show Diagram Code: [go]$$B Black to play and win $$ -------------------- $$ |. X . O O X X O . | $$ |O X O . O X X O X | $$ |O X O O O X X O X | $$ |. X O . O X X O . | $$ |X X O O O X X O O | $$ |O O O X X X X X X | $$ |X X X X O O O O O | $$ |X X X X O . X O . | $$ |. X . X O X . X . | $$ --------------------[/go]

BTW the black configuration in the bottom right corner seems here better (for black) than the one I proposed in my original problem.

Posted: **Thu Nov 02, 2023 7:14 am**

On the same theme I managed to build a very surprising position with an original use of the sending 3 - return 1 configuration (in this position you can count 45 black stones and 45 white stones).

Under japanese rules the game can be stopped there but I assume area counting and komi 5.5

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

Do you see how black can win?
Did you already see such mechanism or is it new for you?
I hope I did not miss something!

Posted: **Thu Nov 02, 2023 8:51 am**

Gérard TAILLE wrote:On the same theme I managed to build a very surprising position with an original use of the sending 3 - return 1 configuration (in this position you can count 45 black stones and 45 white stones).

Under japanese rules the game can be stopped there but I assume area counting and komi 5.5
$$B
$$ ------------------------
$$ |. X X . O X X X O O . |
$$ |O . X O O O X X O . X |
$$ |. . X O . . O X O . . |
$$ |X X X O . . O X O O O |
$$ |O O O O . . O X X X X |
$$ |. . . . . . O X X X X |
$$ |O O O . . O O X . X . |
$$ |X X O O O X X X X X X |
$$ |O X X X X X O O O O O |
$$ |O O O O O X O . X O . |
$$ |. X X . O X O X . X . |
$$ ------------------------
Click Here To Show Diagram Code
[go]$$B $$ ------------------------ $$ |. X X . O X X X O O . | $$ |O . X O O O X X O . X | $$ |. . X O . . O X O . . | $$ |X X X O . . O X O O O | $$ |O O O O . . O X X X X | $$ |. . . . . . O X X X X | $$ |O O O . . O O X . X . | $$ |X X O O O X X X X X X | $$ |O X X X X X O O O O O | $$ |O O O O O X O . X O . | $$ |. X X . O X O X . X . | $$ ------------------------[/go]
Do you see how black can win?
Did you already see such mechanism or is it new for you?
I hope I did not miss something!

Black easy win

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

Posted: **Thu Nov 02, 2023 11:43 am**

dany wrote:
Gérard TAILLE wrote:On the same theme I managed to build a very surprising position with an original use of the sending 3 - return 1 configuration (in this position you can count 45 black stones and 45 white stones).

Under japanese rules the game can be stopped there but I assume area counting and komi 5.5
$$B
$$ ------------------------
$$ |. X X . O X X X O O . |
$$ |O . X O O O X X O . X |
$$ |. . X O . . O X O . . |
$$ |X X X O . . O X O O O |
$$ |O O O O . . O X X X X |
$$ |. . . . . . O X X X X |
$$ |O O O . . O O X . X . |
$$ |X X O O O X X X X X X |
$$ |O X X X X X O O O O O |
$$ |O O O O O X O . X O . |
$$ |. X X . O X O X . X . |
$$ ------------------------
Click Here To Show Diagram Code
[go]$$B $$ ------------------------ $$ |. X X . O X X X O O . | $$ |O . X O O O X X O . X | $$ |. . X O . . O X O . . | $$ |X X X O . . O X O O O | $$ |O O O O . . O X X X X | $$ |. . . . . . O X X X X | $$ |O O O . . O O X . X . | $$ |X X O O O X X X X X X | $$ |O X X X X X O O O O O | $$ |O O O O O X O . X O . | $$ |. X X . O X O X . X . | $$ ------------------------[/go]
Do you see how black can win?
Did you already see such mechanism or is it new for you?
I hope I did not miss something!
Black easy win
$$B
$$ ------------------------
$$ |. X X . O X X X O O . |
$$ |O 5 X O O O X X O 3 X |
$$ |. . X O . . O X O . . |
$$ |X X X O . . O X O O O |
$$ |O O O O . . O X X X X |
$$ |. . . . . . O X X X X |
$$ |O O O . . O O X . X . |
$$ |X X O O O X X X X X X |
$$ |O X X X X X O O O O O |
$$ |O O O O O X O . X O 1 |
$$ |. X X . O X O X 4 X 2 |
$$ ------------------------
Click Here To Show Diagram Code
[go]$$B $$ ------------------------ $$ |. X X . O X X X O O . | $$ |O 5 X O O O X X O 3 X | $$ |. . X O . . O X O . . | $$ |X X X O . . O X O O O | $$ |O O O O . . O X X X X | $$ |. . . . . . O X X X X | $$ |O O O . . O O X . X . | $$ |X X O O O X X X X X X | $$ |O X X X X X O O O O O | $$ |O O O O O X O . X O 1 | $$ |. X X . O X O X 4 X 2 | $$ ------------------------[/go]

Oops you are right Dany. I am stupid, I miss this move. I will try to improve the position in order to apply my idea. Thank you Dany for having take some time on this position.

Posted: **Thu Nov 02, 2023 5:52 pm**

Area counting. Komi 16.5

Click Here To Show Diagram Code: [go]$$ Black to play and win $$ +-----------------------+ $$ | . X X . O X X X O O . | $$ | O O X O O O X X O X X | $$ | . . X O . , O X O . . | $$ | X X X O . . O X O O O | $$ | O O O O . . O X X X X | $$ | . . , . . , O X X X X | $$ | O O O . . O O X . X . | $$ | X X O O O X X X X X X | $$ | O X X X X X O O O O O | $$ | O O O O O X O . X O . | $$ | . X X . O X O X . X . | $$ +-----------------------+[/go]

Posted: **Mon Nov 06, 2023 8:52 am**

dany wrote:Area counting. Komi 16.5
$$ Black to play and win
$$ +-----------------------+
$$ | . X X . O X X X O O . |
$$ | O O X O O O X X O X X |
$$ | . . X O . , O X O . . |
$$ | X X X O . . O X O O O |
$$ | O O O O . . O X X X X |
$$ | . . , . . , O X X X X |
$$ | O O O . . O O X . X . |
$$ | X X O O O X X X X X X |
$$ | O X X X X X O O O O O |
$$ | O O O O O X O . X O . |
$$ | . X X . O X O X . X . |
$$ +-----------------------+
Click Here To Show Diagram Code
[go]$$ Black to play and win $$ +-----------------------+ $$ | . X X . O X X X O O . | $$ | O O X O O O X X O X X | $$ | . . X O . , O X O . . | $$ | X X X O . . O X O O O | $$ | O O O O . . O X X X X | $$ | . . , . . , O X X X X | $$ | O O O . . O O X . X . | $$ | X X O O O X X X X X X | $$ | O X X X X X O O O O O | $$ | O O O O O X O . X O . | $$ | . X X . O X O X . X . | $$ +-----------------------+[/go]

Dany, after you found a simple way of winning with my previous position I also considered the position above you suggested.
I have now in mind some other improvements but let's take first this position above.
First of all I do not see how you can win with a komi 16.5. Do you really confirm this result? For me I need a komi 7.5 in order to win. I must have still missed a good black move.

Posted: **Mon Nov 06, 2023 9:48 am**

Gérard TAILLE wrote:
dany wrote:Area counting. Komi 16.5
$$ Black to play and win
$$ +-----------------------+
$$ | . X X . O X X X O O . |
$$ | O O X O O O X X O X X |
$$ | . . X O . , O X O . . |
$$ | X X X O . . O X O O O |
$$ | O O O O . . O X X X X |
$$ | . . , . . , O X X X X |
$$ | O O O . . O O X . X . |
$$ | X X O O O X X X X X X |
$$ | O X X X X X O O O O O |
$$ | O O O O O X O . X O . |
$$ | . X X . O X O X . X . |
$$ +-----------------------+
Click Here To Show Diagram Code
[go]$$ Black to play and win $$ +-----------------------+ $$ | . X X . O X X X O O . | $$ | O O X O O O X X O X X | $$ | . . X O . , O X O . . | $$ | X X X O . . O X O O O | $$ | O O O O . . O X X X X | $$ | . . , . . , O X X X X | $$ | O O O . . O O X . X . | $$ | X X O O O X X X X X X | $$ | O X X X X X O O O O O | $$ | O O O O O X O . X O . | $$ | . X X . O X O X . X . | $$ +-----------------------+[/go]
Dany, after you found a simple way of winning with my previous position I also considered the position above you suggested.
I have now in mind some other improvements but let's take first this position above.
First of all I do not see how you can win with a komi 16.5. Do you really confirm this result? For me I need a komi 7.5 in order to win. I must have still missed a good black move.

I checked the result with Katago and I still think that Black will win with Komi 16.5.

Posted: **Mon Nov 06, 2023 10:45 am**

dany wrote:
Gérard TAILLE wrote:
dany wrote:Area counting. Komi 16.5
$$ Black to play and win
$$ +-----------------------+
$$ | . X X . O X X X O O . |
$$ | O O X O O O X X O X X |
$$ | . . X O . , O X O . . |
$$ | X X X O . . O X O O O |
$$ | O O O O . . O X X X X |
$$ | . . , . . , O X X X X |
$$ | O O O . . O O X . X . |
$$ | X X O O O X X X X X X |
$$ | O X X X X X O O O O O |
$$ | O O O O O X O . X O . |
$$ | . X X . O X O X . X . |
$$ +-----------------------+
Click Here To Show Diagram Code
[go]$$ Black to play and win $$ +-----------------------+ $$ | . X X . O X X X O O . | $$ | O O X O O O X X O X X | $$ | . . X O . , O X O . . | $$ | X X X O . . O X O O O | $$ | O O O O . . O X X X X | $$ | . . , . . , O X X X X | $$ | O O O . . O O X . X . | $$ | X X O O O X X X X X X | $$ | O X X X X X O O O O O | $$ | O O O O O X O . X O . | $$ | . X X . O X O X . X . | $$ +-----------------------+[/go]
Dany, after you found a simple way of winning with my previous position I also considered the position above you suggested.
I have now in mind some other improvements but let's take first this position above.
First of all I do not see how you can win with a komi 16.5. Do you really confirm this result? For me I need a komi 7.5 in order to win. I must have still missed a good black move.
I checked the result with Katago and I still think that Black will win with Komi 16.5.

Can you please show me Dany in order for me to know where I am wrong? If you agree you take black stones and I try to defend with white. It's your turn.

Life In 19x19

Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position

Re: Curious position