Life In 19x19

Posted: **Wed Feb 23, 2011 5:06 am**

Phelan wrote:What is the status of the top white group in this thread? I think mw42's ko for seki seems the best answer, but I'd like to be sure. If I only get one question, what I'd really like to know is if it would give a good tsumego.

I think it should be alive unconditionally if W doesn't mind losing points in the upper left corner.

Solution

If black starts at B1 then after W2 'a' and 'b' become miai for W to live.

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . a . 2 . . O . b 1 . . . . . . | $$ | . . . . . X . O O X O O . X . . . . . | $$ | . . . O . . . . X , X . . . . X . . . | $$ | . . . . . X . . . X . . . . . . X . . | $$ | . . . O . . . . . . . . . . X O O X . | $$ | . . . . . X . . . . . . O . O O X X . | $$ | . . . O . . . . . . . . O X X X O O X | $$ | . . O . X . . . . . . X X O X O O O . | $$ | . . O X . . . . . , X X O O X X X O . | $$ | . O X X . . . . . . X O . . O X O . . | $$ | . . O . . . . . . . . X O . O X O O . | $$ | . . O X . . . . . . . X . O . O O . X | $$ | . . O X . . . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . X X X X . | $$ | . . . O X . . . . , . . X X X O O O . | $$ | . . . O . X . . . . . . X O O . . . . | $$ | . . . . . . . . . . . X O O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

If black starts from the other direction, here are a few diagrams.

Double ko.

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . 0 . 8 7 . 6 . . . . . | $$ | . . . . . . 1 . . O a 9 . 2 3 . . . . | $$ | . . . . . X . O O X O O 4 X . . . . . | $$ | . . . O . . . . X b X . . 5 . X . . . | $$ | . . . . . X . . . X . . . . . . X . . | $$ | . . . O . . . . . . . . . . X O O X . | $$ | . . . . . X . . . . . . O . O O X X . | $$ | . . . O . . . . . . . . O X X X O O X | $$ | . . O . X . . . . . . X X O X O O O . | $$ | . . O X . . . . . , X X O O X X X O . | $$ | . O X X . . . . . . X O . . O X O . . | $$ | . . O . . . . . . . . X O . O X O O . | $$ | . . O X . . . . . . . X . O . O O . X | $$ | . . O X . . . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . X X X X . | $$ | . . . O X . . . . , . . X X X O O O . | $$ | . . . O . X . . . . . . X O O . . . . | $$ | . . . . . . . . . . . X O O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Another one

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . 9 8 b 6 . . . . . | $$ | . . . . . . 1 . . O . 7 0 2 3 . . . . | $$ | . . . . . X . O O X O O 4 X . . . . . | $$ | . . . O . . . . X a X . . 5 . X . . . | $$ | . . . . . X . . . X . . . . . . X . . | $$ | . . . O . . . . . . . . . . X O O X . | $$ | . . . . . X . . . . . . O . O O X X . | $$ | . . . O . . . . . . . . O X X X O O X | $$ | . . O . X . . . . . . X X O X O O O . | $$ | . . O X . . . . . , X X O O X X X O . | $$ | . O X X . . . . . . X O . . O X O . . | $$ | . . O . . . . . . . . X O . O X O O . | $$ | . . O X . . . . . . . X . O . O O . X | $$ | . . O X . . . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . X X X X . | $$ | . . . O X . . . . , . . X X X O O O . | $$ | . . . O . X . . . . . . X O O . . . . | $$ | . . . . . . . . . . . X O O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

a and b become miai to connect.

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . 7 . . . . . | $$ | . . . . . . 1 . . O . . 3 2 5 . . . . | $$ | . . . . . X . O O X O O 4 X . . . . . | $$ | . . . O . . . . X , X . . 6 . X . . . | $$ | . . . . . X . . . X . . 8 . a . X . . | $$ | . . . O . . . . . . . . b 9 X O O X . | $$ | . . . . . X . . . . . . O 0 O O X X . | $$ | . . . O . . . . . . . . O X X X O O X | $$ | . . O . X . . . . . . X X O X O O O . | $$ | . . O X . . . . . , X X O O X X X O . | $$ | . O X X . . . . . . X O . . O X O . . | $$ | . . O . . . . . . . . X O . O X O O . | $$ | . . O X . . . . . . . X . O . O O . X | $$ | . . O X . . . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . X X X X . | $$ | . . . O X . . . . , . . X X X O O O . | $$ | . . . O . X . . . . . . X O O . . . . | $$ | . . . . . . . . . . . X O O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White just lives.

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . 1 4 . O . 6 5 2 . . . . . | $$ | . . . . . X . O O X O O . X 3 . . . . | $$ | . . . O . . . . X . X . . . . X . . . | $$ | . . . . . X . . . X . . . . . . X . . | $$ | . . . O . . . . . . . . . . X O O X . | $$ | . . . . . X . . . . . . O . O O X X . | $$ | . . . O . . . . . . . . O X X X O O X | $$ | . . O . X . . . . . . X X O X O O O . | $$ | . . O X . . . . . , X X O O X X X O . | $$ | . O X X . . . . . . X O . . O X O . . | $$ | . . O . . . . . . . . X O . O X O O . | $$ | . . O X . . . . . . . X . O . O O . X | $$ | . . O X . . . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . X X X X . | $$ | . . . O X . . . . , . . X X X O O O . | $$ | . . . O . X . . . . . . X O O . . . . | $$ | . . . . . . . . . . . X O O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Going back to this diagram, this is probably the best way to play for black.

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

I think that covers it, if you have any other questions about this let me know. As a TsumeGo it seems like it's interesting.

Also, you can ask more than one question, just don't flood the thread with questions, let everybody who wants a turn have one.

Posted: **Wed Feb 23, 2011 6:06 am**

@stalkor:

Click Here To Show Diagram Code: [go]$$W Seki $$ . . . . . . . . . . $$ . . . . . . . . . . $$ . . . . . . . . . . $$ . O O O . . . . . . $$ O X O X O O . . . . $$ O X X X X . O . O . $$ O X . 1 2 X X O . . $$ . X 6 3 5 . 4 . . . $$ -------------------[/go]

Posted: **Wed Feb 23, 2011 9:19 pm**

A question about joseki. Pros never play :b1:

, so why is it bad? It looks like Black can get a good result.

viewtopic.php?f=15&t=414

Posted: **Fri Feb 25, 2011 5:44 pm**

Click Here To Show Diagram Code: [go]$$Wc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . 1 . b . c . . . . . . . . . | $$ | . . . X . . . . . 2 . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . a . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

In my joseki dictionary I can't find B2. If it is wrong, why?
To me it seems the perfect balance between an extension from the top right and a pincer against W1. Also in handicap games black is advised to play for influence so I prefer to play high instead of c.

Posted: **Fri Feb 25, 2011 6:10 pm**

cyclops wrote:In my joseki dictionary I can't find B2.

Maybe josekipedia isn't as authoritative as your dictionary, but fwiw:

Posted: **Sat Feb 26, 2011 6:59 am**

walleye wrote:A question about joseki. Pros never play , so why is it bad? It looks like Black can get a good result.

viewtopic.php?f=15&t=414

My answer.

If white doesn't have an extension somewhere around a, I don't think he will normally extend at b. However there are some cases where it is not a bad idea.

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

In the case that white already has the extension, white can play at a, if Bb Wc etc. white is very happy with these exchanges, since black has no good follow up on the bottom.

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

If white doesn't have some backup around a, then I think it is normally considered a mistake for white to play at e. White can either play some extension around a, or play Wb Bc Wd Be if he has some potential for a moyo on the bottom.

Click Here To Show Diagram Code: [go]$$ $$ | . . . . . . . . . . . $$ | . . . , . . . . . , . $$ | . . . . . . . . . . . $$ | . . . . . . . . . . . $$ | . . . . . . . . . . . $$ | . . . . . e c . . . . $$ | . . . . . O X b . . . $$ | . . . X X X O . d , . $$ | . . . . X O O . . . a $$ | . . . . . . . . . . . $$ | . . . . . . . . . . . $$ -------------------[/go]

With this being said there are some board positions where it is not a bad idea to play the "inferior" way. Part of being good at joseki is being able to imagine them in relation to the whole board. I have seen some professional games with this shape, but it's probably not very common because it's normally a mistake.

cyclops wrote: In my joseki dictionary I can't find B2. If it is wrong, why?
To me it seems the perfect balance between an extension from the top right and a pincer against W1. Also in handicap games black is advised to play for influence so I prefer to play high instead of c.

B2 is a good move, in fact there are many good moves that you can't find in books

Posted: **Fri Mar 11, 2011 2:43 pm**

Hello tabemasu, sir. I would be honored if I could receive a review of my game in the oza thread in the game analysis forum. I put my heart and soul into that game, and it lasted well over two days. Sincerely, oso. Thank you.

Posted: **Mon Mar 14, 2011 3:36 am**

oso wrote:Hello tabemasu, sir. I would be honored if I could receive a review of my game in the oza thread in the game analysis forum. I put my heart and soul into that game, and it lasted well over two days. Sincerely, oso. Thank you.

Unfortunately I can't seem to download your game to review, if you want to send it to me by e-mail or load it on KGS I would be happy to give you a short review.

Life In 19x19

Ask a question, get an answer (hopefully)

Re: Ask a question, get an answer (hopefully)

Re: Ask a question, get an answer (hopefully)

Re: Ask a question, get an answer (hopefully)

handicap joseki

Re: handicap joseki

Re: Ask a question, get an answer (hopefully)

Re: Ask a question, get an answer (hopefully)

Re: Ask a question, get an answer (hopefully)