Sunday Problem #44

Published 4 Apr 2021 by antti (last edited 11 Apr 2021)

This problem is from Nihon Ki-In’s 150, or 150 Graded Life-and-Death Problems for 7-Dan Players.

Although this shape is hardly anything that could occur in a real game, personally I like this problem because of its straightforward and yet extremely non-obvious solution.

Black to play.

Solution (1)
For Black’s first moves, there is nothing else to do but to cut White apart with 1–4. The real problem comes after this.
Black 5 looks like a promising eye-forming move, but loses to white 6. After 7–8, there is no way for Black to secure two eyes because of her lack of liberties.
If instead of 5 Black plays at 6, white 5 kills.
Solution (cont.)
Black’s unlikely hekomi of 5 is correct. After 6–7, the result is a kō – there is nothing better for either player.

Comments (1)

antti wrote 1 year, 10 months ago:

Solution added.