Sunday Problem #69

Published 27 Sep 2021 by antti (last edited 3 Oct 2021)

I arranged this problem from a shape that appeared in one of my teaching games. The killing technique involved is not too special, but usually appears in the corner rather than on the side like this.

Black to play.

Solution
Failure
Black 1 is often a key point in this kind of a shape, but unfortunately so is white 2. Following, Black has to save her stone with 3 and on, but, thanks to White’s forcing moves with 4–8, finally White is able to form two eyes.
Solution (1)
The placement of black 1 is correct. Black aims to connect her stone to the right with the monkey jump of ‘a’, so white 2 is forced, but then black 3 connects underneath to the left. White cannot block with 4, as black 5 sets up a snapback capture.
Solution (2)
If instead of 4 in the previous diagram White defends with 4 here, Black’s stone anyway escapes with 5 and 7, and White is unable to form two eyes in the remaining space.

Comments (1)


antti wrote 3 weeks ago:

Solution added.