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A problem which shows another of the most popular “paradox” themes. Look out for two prominent set variations.
1...Bxf3 a 2.Sd3+ A S×d3 3.Se2 B 1...R×f3 b 2.Se2+ B Sxe2 3.Sd3 A
1.Qb3! threat 2.Se6+ Ke5 3.Qc3
1...B×f3 a 2.Se2+ B Sxe2 3.Sd3 A; 2...Bxe2 3.Q×g3
1...R×f3 b 2.Sd3+ A S×d3 2.Se2 B; 2...R×d3 3.Qb8
The problem shows the Tura theme, where reciprocally changed continuations and mating moves in one phase are reversed in another. The post-key play also illlustrates the Keller paradox, where a white continuation plays to a guarded square after a second guard has been added.
Dafydd Johnston: A very fine problem. The black Grimshaw in the set play suggests that the two white knight moves will be reversed post key, and this is effected by switching the queen's focus from the half-battery line to the g3-b8 diagonal, accessible vertically and horizontally from b3. Lovely geometry!
Any comments or questions on this problem should be addressed to
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