Sunday Problem #33

Published 17 Jan 2021 by antti (last edited 4 Feb 2021)

Here is an easier problem a ridiculously difficult endgame problem that somehow found its way to a life-and-death problem collection.

This is from the Nihon Ki-In’s 150, or 150 Graded Life-and-Death Problems for 3-Dan Players.

Black to play.

Solution
Gote seki
The book mistakenly says that the bump of black 1 is correct, followed by white
a, black 3, and white 2. However, directly playing 2 is superior, as White can then aim for the killing sequence of white 3, black a, white b, black 3, and white c. Therefore, after white 2, Black is forced to connect at 3, and he can only get a gote seki.
3: elsewhere
Sente thousand-year kō
Connecting at 1 is sometimes better than bumping at 5 as in the previous variation. Following, White answers with 2 and Black plays elsewhere. Later in the game, White will then continue with 4–6 and develop the shape into a thousand-year kō.
As a life-and-death problem solution, a thousand-year kō ranks below seki, but in endgame terms a sente thousand-year kō can often be better than a gote seki. Therefore, this problem doesn’t have a clear-cut correct solution.
If White tries 5 instead of 4, Black will attach at
a and the result is a seki.

Comments (1)


antti wrote 8 months ago:

Solution added. Book authors make mistakes, too!