Life and Death Problem

[burp]

Howdy!

Attached is an interesting Life and Death problem I saw in Maeda Nobuyaki's Tsumego problem book. This is supposively around 5-7 kyu in strength.

BTW ... Black goes first.

Answers?

Enjoy!

mikehansen

[Kuma-san]

Technically this is a no win situation I personally would move on to another section of the board untill I could further pieces into the area to secure my station.

However if you must play this out, then black has an advantage due to the rules of Ko. (I think that's the right rule) if black takes whites piece with a play at 2,7 (row, column) and white begins to form a wall around black then black can use ko to begin to form 3 eyes by playing at 1,6 and then 2,5 and solidfying his eyes at 1,5. Mind you this is all supposing that white is a low kyu player and only attempts a wall and even then black would most likely wind up with a bunch of dead pieces.

But, if white makes an inside play then blacks out of the running without some very careful and lucky moves of it's own.

Again I'd give up this section count my losses and try to bring in reinforcements.

Jeremiah "Kuma-san" Jackson

[Kuma-san]

Sorry that was supposed to go under "life and death decision" not under gaining strength. Gomen nasai. ^_^

Jeremiah "Kuma-san" Jackson

[Nick]

I thought it was perhaps the koan for the week :-)

Nick

[burp]

Howdy!

Unconditional life is possible for black.

Hint: 2,7 is the incorrect answer (think of how white might reply to 2,7).

I'll attach the .sgf file here (actually a .txt file, but when saving the file ... save with the extension ".sgf", then a game editor will be able to graphically represent the .txt file). It may help in a game editor like GoWrite ( http://personal.eunet.fi/pp/paatero/go.html ) to go over the ensuing possibilities.

Here is a link that shows other Go recorders for various computer systems (including PalmPilot) - just go to the menu item "study": http://nngs.cosmic.org/hmkw/golinks.html#study

Enjoy!

mikehansen

[Kuma-san]

Originally posted by burp
Howdy!

Unconditional life is possible for black.

Hint: 2,7 is the incorrect answer (think of how white might reply to 2,7).

I'll attach the .sgf file here (actually a .txt file, but when saving the file ... save with the extension ".sgf", then a game editor will be able to graphically represent the .txt file).

Well personally if I were white and was responding to a play at 2,7 I'd work to dominate the inside or work to complete a solid wall with two plays and sacrifice 3,7 to black. "Killing" His pieces. I don't see how without establishing at least two eyes (which would take 2 plays to establish and 3 to solidfy vs. whites 2 plays to make a solid wall) black could survive. Perhaps you could shed some light on this subject?

Jeremiah "Kuma-san" Jackson

[burp]

Howdy Kuma-san!

I think you've got the right idea of wanting to build a wall and create a thick position as white. In Go, we always want to be looking at the whole board and local situations inevitably have an influence on the whole board. During the course of a game, life and death type problems will come up and be worth a lot of points (in this case, if black can live he gains ... if white can kill black, he gains considerably).

Now moving on to this localized life and death problem ... it's black's turn and he can live provided he plays it right. Otherwise, black will die.

I'll attach a diagram showing what can happen if black plays at 2,7. White can play at 1,6 and black dies. The diagram show the continuation. The continuation is kind of difficult, but presents some interesting plays including a throw-in and a dame-zumari (I can explain in another diagram). In this case, a ko doesn't arise (though it often can in other types of problems).

So, basically, 2,7 isn't an option. But there is a different option for black that will allow black to live unconditionally ... try a few other intersections for black and try to read out the continuation to see how black can live. It may take several minutes to figure out.

Enjoy!

mikehansen

[burp]

Howdy!

Attached is the continuation from the previous diagram ... this shows a dame-zumari type situation. If black plays at 1,3 with #7, then he puts himself in atari and white will capture at 2,5. This type of situation is called dame-zumari. So, black captures with #7 as in the diagram and white can play #8 and black is dead.


BTW ... Kuma-san, the little message on the bottom of your post saying that I edited your message is because I accidently clicked on "edit/delete" post instead of "reply". I did not edit your post. Just my butter fingers at work!


Feel free to post any questions or variations about the above diagrams.

Enjoy!

mikehansen

[Kuma-san]

This was my version of the plays again this was if the same setup was played out against a lower ranked (more like first game) player. It's very similar to the setup that you gave but white made much less agressive moves.

Which at the same time gave black the opportunity to setup and solidfy 3 eyes. But I have no idea how likely my idea is.

Jeremiah Jackson

P.S.- Don't worry we all fat finger keys every now and then (ask any linux op what "rm -r *" does in the root directory.)

[burp]

Howdy Kuma-san,

In your diagram, it appears you'd be right about black living if white plays 2 (as diagramed). I don't believe white would play 4 where it was, but try to do something more with it. However, with black 3 it wouldn't matter since black would live (as far as I can see).

Since black would appear to live with white playing 2 where it did, white would have to play somewhere else to kill black. That place could be 1,6 and then the continuation would be death for black.

I'll attach the correct answer for black now ... first in as a bitmap and then as a .sgf file.

Enjoy!

mikehansen

[burp]

Howdy!

Answer in .sgf file format (actually a .txt file ... remember to save the .txt file with the .sgf extension in order to view in a Go Recorder).

After, black 3 ... white cannot possibly kill black.

Enjoy!

mikehansen