Weekly Problems 2022-B

Problems 606-610

606

Viktor Schtscherbina
Shakhmatnaya Kompozitsiya 1992
Hon. Mention

Mate in 5

Solution

Although it seems likely that the bishop will move along the b8-h2 diagonal several times to threaten mate, so as to decoy the rook to a weak square, such a plan is insufficient. 1.Be5? Rd8! (1…c5! also refutes) or 1.Bg3? Rf8! leaves the rook ready to check, and while 1.Bf4? Re8! looks more promising, no progress is made after 2.Bc7 c5 3.Bb6 Re5. Correct is 1.Bd6! forcing 1…c5, then 2.Be7 sets up a surprising zugzwang. Black has three moves that would keep guarding c5, and White responds to them in different and yet analogous ways, by shifting the bishop along the d8-h4 diagonal. 2…c4 weakens d4 and allows 3.Bf6, a double-attack of d4 and d8, which answers 3…Rd8 with 4.Bxd8 c3 5.Bb6 (3…Re8/Rf8 4.Bd4+ Re3/Rf2 5.Bxe3/Bxf2). If 2…Rc7 then 3.Bg5 similarly controls both e3 and e7, bringing 3…Re7 4.Bxe7 c3 5.Bc5 (3…Rf7 4.Be3+ Rf2 5.Bxf2). And finally 2…Rc6 prompts 3.Bh4, which aims at both f2 and f6 for 3…Rf6 4.Bxf6 c3 5.Bd4. A difficult more-mover that makes interesting use of geometry in the way the white bishop outmanoeuvres the black rook.

Andy Sag: The bishop plays cat and mouse with the c8-rook which cannot escape its fate but White must take care to avoid stalemate, e.g. 1.Bf4? Re8 2.Bd6 Re3! 3.Bc5??
Andrew Buchanan: Looks very simple but really hard to find!
George Meldrum: Great problem!

607

Valery Kopyl
Pidlivailu-75 Jubilee Tourney
Chervoni Girnik 2003, 1st Prize

Mate in 2

Solution

A set mate is arranged for black castling: 2.Qxh7. White has many ways to place a second guard on f7 to threaten 2.Qxf7, which would also deal with 1…Kf8. Three such moves, 1.Rf5?, 1.Be6?, and 1.Sd8? are similarly refuted by 1…Rf8! White castling is tempting, especially since by vacating e1 the move provides for 1…Rf8 with 2.Re1, exploiting the self-block. But 1.0-0? is thwarted by 1…0-0! when the set mate no longer works. The key 1.Se5! counters 1…Rf8 with a new mate, 2.Bd7. Accepting the offered knight, 1…dxe5, opens a line for the d5-rook: 2.Rd8. The set variation 1…0-0 2.Qxh7 remains unchanged. We see thematic castling on both sides and some plausible tries.

Andy Sag: Sacrificial key in Meredith setting.
George Meldrum: A few tries, my favourite being White’s castling.
Bob Meadley: Very clever with the white castling position. Good one.

608

Fadil Abdurahmanovic &
Zlatko Mihajloski
Die Schwalbe 2017, 3rd Prize

Solution

A rook mate on b5 seems probable since the piece would guard the flights on b3 and a5, leaving only the one on c3 to be covered or blocked. But bringing the rook to b5 in four moves is far from an easy task. The king-side pawns prevent the piece from reaching the b-file via the top ranks, so the rook heads for c5 from a lower rank. Many false trails remain, though, when the black units attempt to make way for the white piece, e.g. 1.e2 Kxd2 2.Sf2 Rc1 and the queen cannot clear the c-file, or 1.Ra2 Rg2 2.Qc2 Rxc2 and Black has no suitable way of blocking c3. The solution is 1.Rh2 Rg2 2.Qc1 Rc2 3.Rd2 Rxc5 4.Qc3 Rxb5, which shows matching clearance play on the second rank and the c-file. Both the black rook and queen cross over a critical square, g2 and c2 respectively, on which the white rook lands and then it travels in the opposite direction – the Turton manoeuvre. Each black piece then follows the rook back along the same line – the Bristol theme, with the black rook returning to d2 to stop a prospective queen check, and the queen self-blocking on c3. The bi-coloured versions of two line-clearance themes are thereby fused and doubled.

Andy Sag: Bristol style clearances allow the white rook to reach b5 in four moves and the black rook switchback avoids an unwanted queen check. Brilliant!
George Meldrum: It is plainly obvious that if the queen is placed on c3 then the white rook can mate on the b5-square. No attempt was made to hide this fact yet after many tries, I gave up and looked for many other ways to crack this hard nut. In the end returned to the obvious and found the extremely unobvious beautiful solution.

609

Joe Bunting
To Alain White 1945

Mate in 2

Solution

The black king is constricted in the diagram, but White has difficulty preparing an effective threat. Only 1.Qf6! works, to threaten 2.Qxf5, and surprisingly the key grants three flights to the king. The latter’s moves to f4, d5, and d3 form a Y-pattern and they yield different mates: 1…Kf4 2.Rxg4, 1…Kd5 2.Qe6, and 1…Kd3 2.Qd4. This Y-flights demonstration stands out not only because of the perfect key, but because the three thematic variations all finish with pin-mates. In two cases White’s queen and g5-rook exchange roles in pinning the black bishop and delivering mate. The by-play consists of 1…B~ 2.Bc2 (a transferred mate with respect to the set play, 1…Sf3 2.Bc2) and 1…Sd4 2.Qxd4.

Andy Sag: The key gives three flights answered by pin-mates in a Meredith setting.
Andrew Buchanan: The key offering three flights is impressive. Clean play, and only eleven units.

610

Milos Tomasevic
Mat 1976

Solution

White has only one workable scheme: place the king on h6 and use a promoted queen to check on either g7 or h7 (covering the g8-flight), thereby forcing the black queen to capture and give mate. To allow the promotion to occur without checking Black, the white king must go to d8, and such a trip requires the pawn to act as a shield as well. 1.Kh6 2.c4 3.c5 4.Kg5 5.Kg4 6.Kh3 7.Kg2 8.Kf1 9.Ke2 10.Kd3 11.Ke4 12.Ke5 13.Kd6 14.c6 15.c7 16.Kc6 17.Kb7 18.Kc8 19.Kd8 20.c8=Q. Now the king returns to h6 via another route, taking advantage of how the white queen can cut off both major black pieces simultaneously on f5. 21.Qd7 22.Kc7 23.Kd6 24.Qb5 25.Ke5 26.Ke4 27.Qf5 28.Kf4 29.Kg5 30.Kh6 31.Qh7+ Qxh7. A long, capture-free rundlauf by the white king which visits three of the board edges, elegantly done in miniature.

Andy Sag: Fairly straightforward. Achieving a unique sequence is remarkable with only six pieces!
Jacob Hoover: Themes are interference and Excelsior.