Weekly Problems 2022-A

Problems 580-581

580

Norris Easter
Bristol Times and Mirror 1926, 1st Prize

Mate in 2

Solution

The thematic key 1.Sxe6! self-pins the knight and concedes a flight on e4, adding to the one on c4. Two diagonal batteries are now aimed at the black king, with one utilised in the threat, 2.Sbc5. Black has four defences that place a unit on the e-file and unpin the key-piece, which then fires the other battery in distinct ways. 1…Sfe3 (or 1…Rb1/Rc1) 2.Sec5 – White recovers the e4-flight without unpinning the f5-bishop (2.Sg5+?). 1…Sge3 activates the g1-rook but also allows the h4-rook to guard e4, forcing 2.Sg7 (again not 2.Sg5+?). After 1…Se5 the black knight controls the Q + S battery, but the self-block on e5 permits 2.Sc7 (not 2.Sf4+? cutting off the h4-rook). The fourth main variation sees the e6-knight unpinned by the black king itself, with 1…Ke4 2.Sg5 – an indirect battery mate (2.Sec5+? Kf3). Even the by-play is excellent, making further use of the B + S battery: 1…Kc4 2.Sbxd4 and 1…Sxd2 2.Sxd2. Also, 1…Rxe6+ 2.Qxe6.

Andy Sag: The key deals with the unprovided flight, adds a second flight, self-pins the key piece and allows a check. Lots of variation (horse) play including changed mates, pin mates, battery mates, unpins, a double-check and a switchback.
Jacob Hoover: Because the key is a self-pin, the second battery needs help in order to fire. Five defenses unpin the knight.
Nigel Nettheim: The unprovided flight on c4 leads to a good key.
Thomas Thannheiser: Nice switchback in 1…Sfe3 2.Sec5.
Andrew Buchanan: Lots of line opening and closing to ensure uniqueness for every mate.
Dennis Hale: After staring intensely at the diagram position for about 30 minutes, frankly I am confused, and have to throw in the towel. Doubtless adding to this confusion is that 580 and 579 have Easter coming only one week after Christmas. Heaven knows what Pentecost will bring!

581

Shlomo Seider
Spiros Bikos Memorial Tourney 1991, 5th Prize

Helpmate in 2, Twin (b) Qh7 to b1

Solution

White’s c3-rook and e6-bishop are each half-pinning a pair of black units, but are themselves directly pinned. These black pins hamper attempts by these white pieces to capture and mate along the half-pin lines, even with the white queen’s assistance, e.g. 1.Sh1 Qxf5 2.Kg3 Rxd3??, 1.Rg7 Qxg7 2.Sh1 Bxf5?? Instead, the two sides organise to use the queen for such capture-mates on the two lines. The first part is solved by 1.Sxe4 Qxf5 2.Sxc3 Qxd3. The queen’s initial capture on f5 paves the way for the e6-bishop to pin the black rook. The black knight clears the e4-square for the queen to pass through, and captures the c3-rook as the only hideaway move. The twin shifts the queen to b1, ironically giving the piece immediate access to d3, its mating square in the first solution; but now the queen aims to mate on f5, which was accessible from the piece’s original square on h7. 1.Rxe4 Qxd3 2.Rxe6 Qxf5. Here the queen’s capture on d3 prepares for a pin of the g3-knight by the white rook. The black rook removes the e4-pawn for the white queen and does a hideaway by capturing the e6-bishop. The brilliant solutions incorporate multiple exchanges of functions between the pairs of half-pinned pieces and between the white rook and bishop. The white queen’s reversal of moves across the two parts seems very original.

Andy Sag: A tale of two half-pins; in each case the queen captures to unravel a half-pin then moves again to discover the pin by a piece which is itself pinned. Note that Black moves the same piece twice and ends up capturing the remaining pinned piece, not that it needs to be removed but because it is the only square Black can go to that allows the pin-mate to occur!
Nigel Nettheim: I found solving difficult. The twins match marvellously, with a rank versus diagonal pairing as well as the white queen’s double-hop in opposite directions. Only 5th prize? Sadly, the composer died in the year of this tourney.
George Meldrum: First sight of the diagram I said “Oh my goodness,” trying to solve I said “Oh my goodness,” and finally solving I said “Oh my goodness.” Worth more than 5th Prize.