From: wangs@sol.engr.umbc.edu (Shawe-Shiuan Wang)
Subject: Re: Go Problem
Reply-To: wangs@sol.engr.umbc.edu (Shawe-Shiuan Wang)
Organization: University of Maryland, Baltimore County
Date: Thu, 16 Apr 1992 17:46:35 GMT

Unread news in rec.games.go                                1 article In
article <Edv=Aq200iUyE6Segi@andrew.cmu.edu>, Victor Lin
<vl11+@andrew.cmu.edu> writes:
     
|> >> Go Problem 2: White plays next move 
|> >> . . . . . . . . . . . . . . . . . . .
|> >> . . . . . . . . . . . . . . . . . . .
|> >> . . O X . O . . . . . . . . . . . . .
|> >> . . O X . . . . . X . . . . . . . . .
|> >> . . 1 . . . . . . . . . . . . . . . .
|> >> . . . . . . . . . . . . . . . . . . .
|> >> . . . . . . . . . . . . . . . . . . .
|> >> . . . . . . . . . . . . . . . . . . .
|> >> 1's are unprompt move(black).
|> > 
|> >  . . . . . . . . . . . . . . . . . . .
|> >  . . 3 1 2 . . . . . . . . . . . . . .
|> >  . . O X 4 O . . . . . . . . . . . . .
|> >  . . O X . . . . . X . . . . . . . . .
|> >  . . X 5 . . . . . . . . . . . . . . .
|> >  . . 6 7 . . . . . . . . . . . . . . .
|> >  . . . . . . . . . . . . . . . . . . .
|> >  . . . . . . . . . . . . . . . . . . .
|> >
|> > Both black groups are attacked.
|>  
|> Jeffrey's solution to problem 2 is correct.  Actually, this came up in a 
|> championship game between Cho and Ohtake a few years ago, if I remember
|> correctly.
|> 
|> My comments to problem 2:
|> 
|>   . . . . . . . . . . . . . . . . . . .
|>   . . 3 1 2 . . . . . . . . . . . . . .
|>   . . O X 4 O . . . . . . . . . . . . .
|>   . . O X . . . . . X . . . . . . . . .
|>   . 6 X 7 . . . . . . . . . . . . . . .
|>   . . 5 . . . . . . . . . . . . . . . .
|>   . . . . . . . . . . . . . . . . . . .
|>   . . . . . . . . . . . . . . . . . . .
|> 
|> White can also play 5 as shown above.  If black 6 at 7, then white 6.
|> Compare this diagram with the one below:
|> 
|>   . . . . . . . . . . . . . . . . . . .
|>   . . 4 2 3 . . . . . . . . . . . . . .
|>   . . O X 5 O . . . . . . . . . . . . .
|>   . . O X . . . . . X . . . . . . . . .
|>   . d c 1 . . . . . . . . . . . . . . .
|>   . . 6 . . . . . . . . . . . . . . . .
|>   . . . . . . . . . . . . . . . . . . .
|>   . . e . . . . . . . . . . . . . . . .
|> 
|> This is a basic joseki.  The exchange of black c and white d is VERY,
|> VERY BAD.  I would consider it about a loss of 10 points on black's side.
|> Not only does it use up a ko-threat, it also eliminate the possibility
|> of playing from the left side (black e, then black d threatens white).
|> On top of that, the exchage is a "damezumari" or "taking away your own
|> liberty".  With this exchange, black may be in trouble when white makes
|> a move in black's "potential" territory at the top.

|>   
|> 
|> 
|> 
|> --------------------------------------------
|> Victor H. Lin		          "Life's Hell, especially if  
|> vl11+@andrew.cmu.edu      you make it that way!!" 
|> (412)681-3139			          -- V. L.
|> --------------------------------------------

|> >> Go Problem 2: White plays next move
   Can black cut immediately, if ladder is good for white?
  . . . . . . . . . . . . . . . . . . .
  . 4 3 5 . . . . . . . . . . . . . . .
  . . O X . O . . . . . . . . . . . . .
  . . O X . . . . . X . . . . . . . . .
  . 6 X 2 a . . . . . . . . . . . . . .
  . 8 7 . . . . . . . . . . . . . . . .
  . . 9 . . . . . . . . . . . . . . . .
  . . . . . . . . . . . . . . . . . . .

a = 10

Thank you for your comments, Mr. Lin.

Jeffrey Wang