RTG Problem 66 / Attempts

Sub-page of RTGProblem66
White first, W ko  

hhw: If White first, she can play at W1 and get a ko at circle with a after B2.

Black first, W ko  

hhw: If Black first and he protects against the previous path with B1, White can still get the ko at circle starting with W2.


Not cautious enough  

tderz: 'Sakata' on GoDiscussions suggested B1 here, justifying it with the addidional advantage of being 'bigger' ( as white+circle are in atari it would even be 'sente').

However, White remains vigilant and throws in @W7=B7 with W4 which results in a transposition to the wrong attempt with (only) i) ko (s.b.) or a nakade too big ii):


same theme, but ... W is alive  
only ko  


too big a nakade  
too big a nakade  

if Black was connecting at A:

too big a nakade  

... this would create a living shape !

Herman: Black first

Black first. B11 @ black+circle  
  • B1 prevents ko
  • W2 threatens to connect
  • B3 prevents the connection
  • W4 kills the corner
  • B5-B9 remove the eye in the center.
Black first, continued  

After B13, the best white can get is a rabbity six eyeshape in the corner. And since black ahs an eye in the corner, it can never be seki. White is dead.

hhw: Ah, missed the dead shape. That's what I get for attempting so early in the morning. :)

Herman: White first

White first  

After W7, it will be ko

B12 @ black+circle, W13 @ black+square, B14 @ W11  

unkx80: The people who posted the correct solution are Tommie on godiscussions.com and Herman on Sensei's Library. Unfortunately, Sakata's optimization does not work. Nice work, everybody! =)

As it turns out, the two people who posted the correct solution are also long-timers who are familiar with my style of problems. Admittedly, I have used this theme in a few of my other compositions, except that in this problem I have obscured it with quite a couple of distractions.

I'll post up a summary solution post later.

RTG Problem 66 / Attempts last edited by Unkx80 on November 9, 2009 - 16:24
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