Sunday Problem #14

Published 6 Sep 2020 by antti (last edited 4 Oct 2020)

This problem is from my recent teaching game against Daniel Hu 5d in the bga Strong Player Development Programme. A review of the teaching game can be watched here.

Black to play.

Slightly suboptimal solution
Black’s hane of combined with the placement of 3 is a strong combination – however, Black has to be wary of White’s resistance with 8–10. Finally, the result is a one-move approach kō in Black’s favour.
Best solution
It is best for Black to directly start with the placement of 1. Following, the best White can do is setup a desperate-looking kō for life with 2–6 – but, categorically speaking, this is the same one-move approach kō as in the suboptimal solution. The only difference is that now black has more local kō threats available.
Note that if instead of 4 White played directly at 6, black 4 would kill unconditionally.
White fails
In response to the placement of black 1, white 2 looks like it might be difficult to kill; but black 3 manages this perfectly. White cannot even manage a seki with 4 because of the black throw-in of 5.

Comments (1)

antti wrote 7 months, 3 weeks ago:

Solution added.