Deceptive mate-in-one problems – An addendum

Last month’s Walkabout covered a class of mate-in-1 problems that involves a retro-analytical “twist.” In these compositions, we can prove that the diagram position cannot be legal with White to play; that implies it is Black’s turn, and thus White executes the mate only after a black move. One of the cited examples by Nikolay Zinovyev presents a rook cross in which four different moves of a black rook induce distinct mating responses. This is a pleasant idea, but there are two minor drawbacks: (1) White has no mate-in-1 try, and (2) one variation contains a promotion dual, which I think is distracting in a one-mover. An apparently simple way to fix both issues comes to mind – replace the c7-rook with a queen and the a7-pawn with a bishop. Then 1.Qxb7? is a mating try, while …Rb8+ permits 1.Qxb8 only. Alas, …Rxa7 now brings a ruinous dual, 1.Qxa7/Qb8. After attempting other ways to remove the two flaws, I believe it’s not feasible to do so while preserving the economy of a miniature (seven pieces at most). Still, I produced a couple of slightly heavier problems that employ a new matrix and incorporate the desired features with bonus play.

This setting includes a mating try, 1.Qxg2?, that is unplayable as Black has no legal last move. With Black to play, …Rxg1 1.Qxg1 and …Rxh2 1.Qxh2 are dual-free. Completing the rook cross are …Rxg3+ 1.Kxg3 and …Rf2+ 1.Kxf2, which utilise the B + K battery – a device that distinguishes the problem from its predecessor. Furthermore, we see an extra variation, …Rxe2 1.Kxe2. Are all the positive attributes worth an eight-unit setting? Probably! In any case, given the battery set-up, it seems a pity that 1.Kxg4 never occurs as another mate. Can we squeeze in such a variation as well?

As the next diagram shows, it is possible to add a sixth variation, but this is only a scheme because promoted force is generally disallowed in orthodox problems. Frustratingly, neither of the dark-squared bishops could be replaced by a pawn (regardless of board orientation) without rendering the position unsound. To make the matrix work, we have to shift the black king away from the corner, and that necessitates more units to constrict the royal piece.

This ten-unit version contains all the sought-after features: a thematic try, 1.Qxb5?, and six accurate variations, …Rxa5 1.Qxa5, …Rxb6 1.Rxb6, …Rb4+ 1.Kxb4, …Rc5+ 1.Kxc5, …Rxb3 1.Kxb3, and …Rxd5 1.Kxd5. The white knight, which ensures that …Ka7-a6 couldn’t be the previous move, also has a forward-play function in …Rxb6 1.Rxb6. On the downside, the three pairs of variations look rather symmetrical. A similar question arises, as to whether the added content justifies the extra material used. Once again, I am inclined to say yes, though it’s debatable which of the two versions is really better.

Deceptive mate-in-one problems

9 Jul. 2025