Beginner Exercise 31 / Solution

Sub-page of BeginnerExercise31

satyreyes: I would like to see a continuation or two here. I got as far as W1 B2, but I don't see why W3 solves white's problem and I'm not confident I'd know how to prove the kill if black kept playing. Can't black still get eyespace by winning the capturing race? Or is that not enough because the a region is only good for one eye, and the others are falsifiable? What about trying for another eye at b?


MJH?: I had the same thought at first satyreyes. I thought that once black connected at 6 and 'a' he would have a second eye. Here's why not.

dencarl: Both white moves are designed to remove black eyes. After W3 black has only one eye remaining.

airfrog: It might be worth checking out Recognizing an Eye if it's hard to see why W3 removes the possibility for an eye at b or c, or why Black can't make an eye elsewhere.

I apologize I am very low but I don't see how black can make an eye on the left side. In the diagram above, black would have to play at both 3 and C to get an eye. Otherwise, throw-ins at 3 would kill the eye. It seems to me that black is dead (squared four is the only "real" eye shape, moreover it's partially filled) and white only has to avoid careless disconnection/capture of his surrounding groups to win.

timh, 15k: No, if Black gets 3, b and c are miai for an eye.

unkx80: This "Continuation" diagram has at least two mistakes. Firstly, either W5 or W7 should connect at b. Secondly, B8 can capture at b to make an eye at the point originally marked as B8.


I put this on the /Attempts page. It looks like this is pretty poor play for Black, but I'm not too sure myself.

Comment: After W3, Black is dead because the group has only one eye. Therefore, all following moves in this diagram can be considered mistakes, for Black because they don't do anything to save the group (only more prisoners for White), and for White because they're not necessary (these are plays in White's own territory now). Both players would be better off to tenuki.


Jacob4Jesus: This diagram is marked "Failure", but I don't see how. Doesn't B still have only one real eye?

JoelR: No, B4 captures, so Black has an eye at a.

another failure?  

Radvendii: Another failure because it is an even capturing race and black has sente. So... almost works.

Voroplav?: What about 5 to lower b? This will destroy one more eye. Even if W takes both a's, B will be able to capture all white stones, as they will have only one real eye...

timh?: But B4 is a mistake...

yes, another failure  

timh?: Now either a or b secures life for black, so black lives.

unkx80: W1 is wrong. B2 at a lives.

Beginner Exercise 31 / Solution last edited by on April 29, 2016 - 12:40
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