From: Colin Paul Adams <colin <at> COLINA <dot> DEMON <dot> CO <dot> UK>
Date: 4 feb 2000
Subject: CHU: problems with A13

The published solution does definitely NOT demonstrate the longest
defence. After:

1. +Ky - 4a, +DK x 4a
2. FL - 5d+, G - 3b
3. +FL x 3b, K x 3b
4. +DK - 3d, Ky - 3c
5. +DH - 7f
the published solution gives S - 4c.
White can hold out longer by playing K - 2b instead. Then follows:

6. +DK x 2c x1b, K x 1b
7. +DH - 2a,     K x 2a
8. Ph - 4c+,     K - 1b
9. +Ph - 2a,     K - 1c
10.+Ph x 1a Mate (in 19, as opposed to 15 in the published solution)

But somewhere, there is even better (?, well, longer anyway) defence,
as my program cannot find a mate at a search depth of 22. Maybe the
problem is defective.

--
Colin Paul Adams
Preston Lancashire