Home > Weekly Problems (14) >
Weekly Problems with Solutions (14) < Prev

326. David Shire
Australian Chess 2007
Mate in 2

The key 1.Rg4! protects e4 to create the threat, 2.Sb4. The variations 1…Re5 2.Sf6 and 1…Bc6 2.Sc7 show excellent, analogous play. In each case Black shuts off a white piece – the h8-bishop or the c8-rook – so that the threat-move, which interferes with the white queen, would give a flight on the fourth rank; but each defence also self-blocks, enabling a knight mating move that disrupts a line controlled by the same white piece cut off by Black. In 1…Rxh8 2.Rg5 and 1…Bxc8 2.Qxb5, Black removes the white line-pieces altogether but exposes the king to orthogonal mates on the fifth rank. 1…Sc2 2.Qxb3 and 1…Sd3 2.Qd4 see the black knight interfering with the queen on d1 twice to permit queen mates. The problem hence presents three pairs of corresponding variations. There’s by-play with 1…Ba3 2.Sxc3, 1…Rxe4 2.Qxe4, and 1…Qd4 2.Qxd4.

Andy Sag: The key guards the e4-knight threatening 2.Sb4 and leaves the queen en prise but frees it up to mate in four variations.
Jacob Hoover: In the diagram, the white queen – the only piece guarding the e4-knight – is threatened with capture by the b5-pawn. Of the squares near the black king that the white queen guards, all of them, with the sole exception of e4, are guarded by other white units. So the solution seems to be to put another guard on e4, and doing so also threatens 2.Sb4.

327. Frederick Hawes
British Chess Problem Society Tourney 1943
1st Prize
Mate in 3

The black knight has four legal moves including two checks, all with set play prepared: 1…Sb6+ 2.Qxb6 and 3.Qb1/Qb2/Qc5/Qc7; 1…Sc5+ 2.Qxc5; 1…Sb2 2.Qc5+ Sc4 3.Qxc4; and 1…Sc3 2.Qc5 and 3.Qa3/Qxc3. The key 1.Qg4! entails a short threat, 2.Qd1, and completely changes White’s answers to these defences. 1…Sb6+ 2.Kd6 (threat: 3.Qd1) Sc8+ 3.Qxc8, or 2…Sc4+ 3.Qxc4. 1…Sc5+ 2.Kc8 and 3.Qd1/Qc4. 1…Sb2 2.Qe2 and 3.Rc2. After 1…Sc3, not 2.Qc4? Qxg7! but 2.Qb4 (threats: 3.Qa3/Qb2/Qxc3) Sa4/Sd1 3.Qb1. In response to the knight checks, White makes a leisurely king move and, in the case of the first variation, invites two further checks!

Andy Sag: The threat is a short mate but we have all four possible knight moves providing a defence; the first variation involving successive checks is the highlight.
Jacob Hoover: After 1..Sb6+ and 1…Sc5+, if White moves the king anywhere other than the noted squares Black has a delaying check.

328. Edgar Bettmann
Henry Wald Bettmann &
Jacob Bettman

South Australian Chronicle 1883
Mate in 2

Set mates have been arranged for every possible black move: 1…d3 2.Qxd3, 1…e4 2.Qd6, 1…Ke4 2.Qf3/Qg2, 1…B~ 2.Bxb7, and 1…S~ 2.Sxf6. But White has no way of preserving all of these variations, e.g. 1.Qh2? d3!, 1.Qh3? e4! The withdrawal key 1.Qe1! (waiting) yields three new mates: 1…d3 2.e4 (nice en passant avoidance), 1…e4 2.Qxa5, and 1…Ke4 2.Qh1. The remaining play is unchanged: 1…B~ 2.Bxb7 and 1…S~ 2.Sxf6. The only flaw of this well-keyed mutate is the set dual, 1…Ke4 2.Qf3/Qg2, fixable by adding a white pawn on h2 and a black one on h3.

Andy Sag: Looks like an old classic; complete block with five variations including three changed mates.
George Meldrum: The range of tries, and the changed mates, combined with the innocuous looking key move make this a pleasing problem.

329. Arnoldo Ellerman
The Brisbane Courier 1919
1st Prize
Mate in 2

After the key 1.Qb2!, White threatens 2.Qg7/Qh8. Black has three defences on c3 that interfere with the b3-rook and unpin the white bishop on the third rank. This bishop is thus allowed to fire the R + B battery, playing to a different square each time to shut off a black line-piece. 1…Sc3 2.Be1, 1…c3 2.Bf4, and 1…Bc3 2.Be5. The direct unpin 1…Rxb2 enables the battery to fire one more time – 2.Bf2. A fourth defence on c3 sees the black rook closing one white queen line and opening another: 1…Rc3 2.Qb8. Lastly, 1…Rxg3+ permits 2.Rxg3.

Andy Sag: Sacrificial key and six variations, four involving different placements of the unpinned battery trigger bishop.
Jacob Hoover: A nice presentation of a line-effect theme. We also see a "defences on same square" thing going on.
Nigel Nettheim: Nice handling of the four defences on c3.
George Meldrum: An alluring setting with a wicked key move that provides threats by the double. But it is all in the variations, most of which centre around blocking the queen’s path on c3. My favourite is 1…Rc3 2.Qb8.

330. Niharendu Sikdar
Australian Chess 2006
Helpmate in 7

This tough helpmate is solved by 1.d5 a3 2.d4 axb4 3.d3 b5 4.dxe2 b6 5.e1(B) bxa7 6.e2 a8(Q) 7.e3 Qf3. Both thematic pawns depart from their initial ranks and eventually promote, so the Excelsior idea is doubled. The unusual motive for the black promotion accounts for the difficulty. Black promotes not for the purpose of employing the new piece (e.g. to self-block), but solely to clear e2 for the e3-pawn. A bishop promotion is required since another piece on e1 would either check White or control the mating square f3.

Andy Sag: Not hard to see that the promoted queen could get to f3 in seven moves but only if the e4-pawn was not there. Working out how to deal with the e4-pawn took forever. A number of near misses in eight moves make this a very difficult and tantalizing problem.
George Meldrum: I can personally vouch that there are about 20 other ways to do this in eight moves. It took most of my Saturday, and it was only in the freshness of Sunday morning when it came into view. There is only one was to describe this problem: frustratingly good.

331. Alexander Goldstein
Lunds Dagblad 1946
5th Hon. Mention
Mate in 2

The key 1.Se4! threatens 2.Sd6. The two black knights defend by capturing the white queen, to create a flight on e7. But each knight move also opens a white line to an eighth-rank square controlled by the e7-pawn, enabling White to promote on that square and give a pin-mate: 1…Sfxe6 2.exf8(Q) and 1…Scxe6 2.exd8(Q). The knight defences are thus anticipatory self-pins, and there’s a paradoxical element as well in that the white mates on f8 and d8 occur only after they have been guarded by the black knights. Two more thematic defences yield a flight by capturing the e7-pawn, and again they lead to pin-mates: 1…Qxe7 2.Qg8 and 1…Bxe7 2.Qc8. The impressive pinning strategy shown on the e-file also entails an exchange of functions between the white queen and pawn. One by-play variation is 1…Rc6 2.Qd7.

Andy Sag: All five defences have set mates including two pairs of pin-mates. The knight defences open white lines aimed at the promotion mating squares.
Nigel Nettheim: The capturing promotions make a nice symmetrical matrix, causing any black knight that ventures onto e6 to be pinned. The c3-rook and d3-pawn are not needed, but provide the minor variation; I’d vote to remove them.

332. Brian Tomson
The Problemist 1983
Series-helpmate in 17

A plausible mating scheme involves placing the black king on a8 and two pieces on a7 and b8 to self-block, and this would enable the white bishop to mate by capturing an interposing piece on the long diagonal. The self-blocking pieces must be bishops to avoid interfering with the mate, so Black promotes both pawns to this type of unit. And since to check during the move sequence is forbidden, Black uses the knights to shield the white king from the promoted bishops. 1.Sf6 2.Se4 3.Sf2 4.g1(B) 5.Bh2 6.Se4 7.Sd2 8.c1(B) 9.Ba3 10.Sb3 11.Sd4 12.Bc5 13.Ba7 14.Sb6 15.Sc6 16.Ka8 17.Bhb8 Bxc6.

Andy Sag: The final scenario with the black king on a8 is fairly obvious but how to get there in 17 moves without checks is the task.
Nigel Nettheim: The series of tasks in logic is elegant, though not difficult. For instance, a knight must occupy b6, for on c5 or d4 it would prevent mate.
George Meldrum: Another try was to get the black king to f1 and mate with Be2 but it just fails the 17 moves stipulation. The problem would have been much easier if the white king were on another square!
Andrew Buchanan: Not complicated but it was fun to follow the false trails and eventually see all the constraints that led to a unique story solution. Fun to see the knight and bishops dancing round the white king.

333. Joseph Opdenoordt &
Petrus Koetsheid

The Brisbane Courier 1930
5th Prize
Mate in 2

The initial position is a complete block, with set mates prepared for all of Black’s moves: 1…B~ 2.Qb2 and 1…g4 2.Qh4. The key 1.Qh2! (waiting) preserves the set play but also unpins the black knight. A random move by the piece opens a white queen line for 1…S~ 2.Qe5. Two correction moves disable the queen mate but they cause self-blocks that are exploited by the rooks: 1…Sg6 2.Rgf7 and 1…Se6 2.Ref7. A third correction interferes with the black bishop and permits yet another queen mate: 1…Sd3 2.Qh6.

Andy Sag: The key unpins the black knight to add four variations to the two already set in an economical eleven-piece setting.
Ian Shanahan: Three excellent corrections by the black knight.
George Meldrum: Quite a cute problem that frees the black knight to add to the set play with four new mates.
Nigel Nettheim: The black knight comes into play with 1…S~ 2.Qe5 and three nice corrections. Very economical.
Andrew Buchanan: 1.Ka2? gets checked and 1.Kb2? amusingly occupies a key square that White would need. 1.Qg3? (threat: 2.Qxg5) was promising but 1…Bg6! controls f7. Still the idea of pinning the black knight along a new line looks cool, and 1.Qh2! covers e5 indirectly. It's an obvious idea to have lots of black knight defences, to break the woodenness of the white symmetry. Perfectly dual-free.
Brian Stephenson: Clean, elegant setting with the c7-pawn being needed to stop the dual 2.Qd6 after some black knight moves. Much enjoyed.
Jacob Hoover: This problem had a lot of things for me to like: black correction, line effects, a complete block, and a proliferation of queen mates.

334. Abdelaziz Onkoud
Australian Chess Problem Magazine 1996
Mate in 3

The thematic set play consists of two pairs of variations that involve reversals of White’s second and third moves (as the A-B-C-D labels indicate): 1…Rxe4+ 2.fxe4+ [A] Bxe4 3.g8(Q) [B], 1…Bxe4 2. g8(Q)+ [B] Rxg8 3.fxe4 [A], 1…Rxd4 2.Sc7+ [C] Bxc7 3.Qxd4 [D], and 1…Bxd4+ 2.Qxd4+ [D] Rxd4 3.Sc7 [C]. After the key 1.Kd3!, Black’s four initial captures in the above variations all stop the threat of 2.Se3, but thanks to the white king’s new position, the continuations are all changed: 1…Rxe4 2.g8(Q)+ [B] Bxg8 3.fxe4 [A], 1…Bxe4+ 2.fxe4+ [A] Rxe4 3.g8(Q) [B], 1…Rxd4+ 2.Qxd4+ [D] Bxd4 3.Sc7 [C], and 1…Bxd4 2.Sc7+ [C] Rxc7 3.Qxd4 [D]. Again we see two reversals of White’s second and third moves. And further, an elaborate form of reciprocal change is rendered with respect to the set play, in that after each pair of defences, White swap not only the two second moves around but the two mating moves as well. There’s by-play with 1…Rc3+ 2.Sxc3+ Sxc3 3.Qb3. A dense pattern yet crisply shown.

Andy Sag: Short threat swaps bishop and rook checks and adds four changed mating plays to one preserved set play.
Brian Stephenson: The short threat of 2.Se3 just had to be investigated, which meant only one possible candidate for key, which I tried and so very quickly solved this. It was only after I finished writing down the variations that I realised that there might be a double reciprocal change. And there was!
Nigel Nettheim: A thematic key. The respective black rooks and bishops cannot both continue to guard the vital squares g8 and c7. A heroic doubling (or quadrupling) of the theme: alternated white second and third moves respond to alternated black bishop and rook captures. The d7-pawn avoids a dual 1…Rxe4 2.Bxc4+ Kc6 3.d5.
Jacob Hoover: A whole lot of reciprocal changes occur between the set and actual play, and the black rooks and bishops interchange roles. A very interesting theme here; and I enjoyed it immensely.
George Meldrum: A heavily engineered setting with full military precision. The battlefield contains diligent distraction tactics. A medal should go to General Onkoud.

335. Laszlo Apro
The Australasian Chess Review 1932
1st Prize
Mate in 2

The key 1.Qh3! threatens a pin-mate, 2.Qe6. Any black move to b4 or c4 would unpin the d4-knight and thwart the threat, and four such defences result in two pairs of mutual interferences between the rooks and bishops. 1…Bb4 2.Rc4, 1…Rb4 2.Sxc5, 1…Bc4 2.Sc3, and 1…Rc4 2.Qd3. Hence the problem exhibits a double Grimshaw, which is additionally unified by the common unpinning motive. Four other variations make up the by-play: 1…Qh2/Qh1 2.Sf2, 1…Bxe2 2.Rxe2, 1…e5 2.Sd6, and 1…f5 2.Qf3.

Brian Stephenson: With 1…Qxd1! taking a flight at e3 and unprovided, one is encouraged to look for a threat on the e-file to cover e3. That's going to be by the queen, so 1.Qh3! (2.Qe6) is soon found.
Andy Sag: The key sets up a pin-mate threat with four unpin defences including two already set, all creating interferences to allow different mates. Removal of the e2-pawn is answered by a required double-check mate and finally there are three set plays involving two unguards and a self-block making eight variations in total.
Nigel Nettheim: The main play is the pair of rook-bishop (Grimshaw) interferences on b4 and c4.
Jacob Hoover: Four moves unpin the knight and these occur in two Grimshaw pairs.
George Meldrum: Not much in new play after the key, but the problem forces you to work through some very nice variations. My choice one is 1…Bb4 2.Rc4.

336. Percy Francis Blake
Sydney Morning Herald 1911
3rd Prize
Mate in 2

A great key, 1.Bb6! (threat: 2.Qc5), concedes two flights to the black king, enabling it to execute a pair of discovered checks: 1…Kb4+ 2.Sfd5 and 1…Kc3+ 2.Scd5. The key also opens the a-file and permits a third discovered check: 1…axb5+ 2.Sa6. The three cross-check variations are supplemented by 1…Bd4 2.Qxd4.

Andy Sag: The key allows three discovered checks answered by battery mates. Two of these are flights and the mates are double-checks, required in the 1…Kc3 variation. The black rook and a- and b-pawns can be removed if the h8-bishop is relocated to g7, reducing the setting to eleven pieces albeit with one less variation.
Ian Shanahan: A rather tricky flight-giving key to find. The cross-check plus self-block is delicious. Clearly, though, the two batteries must be activated somehow.
Brian Stephenson: Solved on the “Wouldn't it be nice if…” principle. The d2-pawn stops 1.Sfd5+ cooking. A high-class traditional two-mover and much enjoyed.
Thomas Thannheiser: Cross-check problem from good old Good Companions time with the relatively obvious key.
George Meldrum: After the key move the black king is given two flight squares – wow. After the key move Black can check the white king three ways – wow. In summary… wow!

337. Michal Dragoun
Australian Chess Problem Magazine 1995
Helpmate in 2
Twin (b) Pc4 to d4

The diagram position is solved by 1.Rec3 Rh7 2.Bd3 Bf2. Black’s initial rook move, besides interfering with the b2-bishop, crosses over the critical square d3. After White covers a potential flight with the rook, Black plays the g6-bishop to the critical square to cut off the black rook, allowing a long-range mate by the white bishop. The twinning, by shifting the c4-pawn to d4, opens the c-file but closes the long diagonal. The resulting solution is 1.Bc2 Bb8 2.Rd3 Rh6. Now the first bishop move involves an interference with the c1-rook as well as critical play over the d3-square. White uses the bishop to guard another flight, then the e3-rook moves to the critical square to cut off the black bishop, enabling the white rook to give a long-range mate.

Thomas Thannheiser: Exchange of functions between g6-bishop/e3-rook and g3-bishop/h3-rook on the other side.
Jacob Hoover: In each part, both black self-interferences are necessary for a valid mate.
Andy Sag: I found it easier to solve (b) first. Nice twin where rooks and bishops swap preparation, mating and interference roles.
Brian Stephenson: All the interesting play is by Black, with White just moving into position.
Nigel Nettheim: Neat twins.
Andrew Buchanan: Quite fun.
George Meldrum: Poetry in motion.

338. Arthur Mosely
Good Companions 1914
2nd Prize
Mate in 2

Set mates are arranged initially for every possible black move: 1…Be5 2.Be4, 1…Bd6 2.Sb6, 1…Bc7 2.Sxc7, 1…Sa~ 2.Qc6, 1…Sf~ 2.Qe6, 1…b4 2.Bc4, and 1…c4 2.Sb6. Tries that attempt to preserve the set play include 1.Qb6? Sc6! and 1.Bb2? c4!, while 1.Re8? threatening 2.Be4 is spoiled by 1…Be5! After 1.Sc4! (waiting), the key-piece loses control of c4 and c6 but observes e5 and d6, leading to these changed mates: 1…Be5 2.Rxe5, 1…Bd6 2.Qxd6, 1…Sc6 2.Sab6, 1…Sc8 2.Qb7, and 1…b4 2.Be4. A new defence 1…bxc4 allows 2.Bxc4. The rest of the play is as set: 1…Bc7 2.Sxc7, 1…Sf~ 2.Qe6. This terrific mutate achieves an Ideal Rukhlis (long before the composer Rukhlis was born!), which combines changed and transferred mates in a pattern as indicated by the following move labels: set 1…Be5 [a] 2.Be4 [A], 1…Bd6 [b] 2.Sb6 [B], 1…b4 [c] 2.Bc4, 1…Sc6 [d] 2.Qxc6; post-key 1…Be5 [a] 2.Rxe5, 1…Bd6 [b] 2.Qxd6, 1…b4 [c] 2.Be4 [A], 1…Sc6 [d] 2.Sab6 [B]. Remarkably, a third transferred mate occurs between the set 1…b4 [c] 2.Bc4 [C] and the actual 1…bxc4 2.Bxc4 [C].

Andrew Buchanan: After 1…Bd6/Be5, 2.Qxd6/Rxe5 look plausible as new mates, but unfortunately can just be captured. So is 1.Sc4 too obvious as a key then? It offers itself for sacrifice, after which 2.Bxc4. Turns out to be a lucky first guess! All the lines are totally unique: I like this one.
Brian Stephenson: A tough mutate. Tough because the mates after 1…Bd6 and 1…Be5 are not as interesting as those before the key and because the a3-bishop is unused after the key.
George Meldrum: Nice key move. Heaps of changed mates. A very high-class problem overall.
Nigel Nettheim: A good key in a complete block, and most mates (all the interesting ones) are changed. Brilliant! The a3-bishop just sets a mate after 1…c4, completing the block and thus hiding the key.
Jacob Hoover: A very interesting mutate in that: (a) the set mates from the bishop's correction moves are transferred to other defences in the actual play; and (b) the set mate for 1…b4 is transferred to the pawn move created by the key.
Paz Einat: A great problem, way ahead of its time. Not only does it show an Ideal Rukhlis, but it also involves an additional mate transference, making it a triple Rukhlis.

339. Leonid Makaronez
Australasian Chess 2009
Mate in 3

A first-class key 1.Se5! yields three flights to the black king. The threat is 2.Sg4+ Kxf4 3.Bh6. Black’s only defences are to take the flights, and each move leads to a different continuation. 1…Kxd4 2.Sd3+ Kc4 3.Rc6 or 2…Ke3 3.Rxg3. 1…Kxe4 2.Sc4+ Kd5 3.Se3 or 2…Kxf4 3.Bh6. 1…Kxf4 2.Sf3 and 3.Bh6 (not 2.Sf7? Ke3!). Good variety of battery play.

Jacob Hoover: The key grants three flights to the black king and sets up two batteries. There wasn't really anything in this problem that stood out to me except for the battery plays (yay!).
George Meldrum: Sometimes you look a problem and say, wouldn’t it be nice if that was the first move. Invariably it is a way out move that would never work. Such is the case here where I almost gave in to the tricky continuations. This problem is insane.
Nigel Nettheim: The best possible key attracts attention, making the solving a little easier. The outlying c8-knight, stopping 1.Sh4 and 1.Se7, seems a good deal better than white pawns on those squares. Excellent.
Brian Stephenson: The key gives three flights so the “wouldn't it be nice if…” approach to solving was again successful. The quiet continuation after 1…Kxf4 came as a surprise though. Good to see that the g2-rook isn't just there to guard f2. An enjoyable time for the solver courtesy of one of today's most prolific composers.

340. Juan Kloostra &
Denis Saunders
Australian Chess Problem Magazine 1997
Mate in 2

The key 1.Qxb4! (threat: 2.Qxf4) unpins the e6-bishop and self-pins the queen. The freed bishop produces two variations, unpinning the queen in one and checking in the other: 1…Bc4 2.Qe1 (pin-mate) and 1…Bxd7+ 2.Sxd7. The queen gives two more pin-mates by moving along the pin-line in 1…Rf6 2.Qe4 and 1…Bc1/Bd4 2.Qd4. The threat still works if Black accepts the granted flight, 1…Kf6 2.Qxf4, though it could be viewed as a distinct variation since the king is mated on a new square.

Ian Shanahan: The unpinned bishop then unpins its unpinner, the queen – the Schor theme. Sweet!
George Meldrum: First impressions of this problem setting were that it was awkward and clumsy. Once the key is found this feeling is overturned with an array of positives: (1) flight square given to the black king; (2) self-pinning of the white queen while unpinning the black bishop; (3) allowing a check on the white king; (4) all new mates, not being from set play.
Nigel Nettheim: The key is a highlight, allowing a capture with check as well as a flight, and it is a (minor) capture; it took me some time to find. The re-pinning of the e6-bishop after 1…Kf6 is another highlight.
Brian Stephenson: With 1…c6 and 1…Sc6, giving a flight at e4 and unprovided, it does not take long to find the excellent key. The star variation is 1…Bc4 2.Qe1. Old-fashioned quality and very enjoyable.

341. Alex Boudantzev
The Problemist 1969
2nd Hon. Mention
Mate in 2

Two thematic tries and the key are all Novotny moves that place a white piece on a square where two black defensive lines intersect. By cutting off two black pieces simultaneously, White creates two threats, which are separated when each line-piece captures the white unit. 1.Re4? (2.Bd5/Qa1), 1…Rxe4 2.Bd5, 1…Bxe4 2.Qa1, but 1…Sc3! refutes. 1.Rf4? (2.Rb8/Qa1), 1…Rxf4 2.Rb8, 1…Bxf4 2.Qa1, but 1…Bb7! refutes. The key 1.Qf4! threatens 2.Rb8/Ra4, separated by 1…Rxf4 2.Rb8 and 1…Bxf4 2.Ra4. Black has two defences that handle both threats: 1…Bb7 2.Sb6 and 1…Bd5+ 2.Bxd5. A striking Meredith (12-unit) setting with no pawns.

Jacob Hoover: White has mates prepared for quite a few black moves in the diagram, e.g. 1…R~file 2.Ra4, 1…Be1/Bf2 2.Rb8. These variations provide a clue to the key: they say that Ra4 is mate if a4 isn't guarded, and that Rb8 is mate if b8 isn't guarded. Therefore, it is not difficult to find the key: 1.Qf4! invokes the Novotny theme to threaten both Ra4 and Rb8.
Ian Shanahan: This elegant Meredith parades three Novotnys.
George Meldrum: Worthy of note are the number of tries, especially 1.Re4? and 1.Rf4? as these provide dual threats of mate to avoid. I class this as a pop-corn problem.

342. Joseph Wainwright
The Brisbane Courier 1921
Mate in 3

The white queen aims for a1 while retaining its control of g2 with 1.Qg7! The threat is 2.Rxh3 followed by 3.Qa1 or Qxg2 (2…Kg1 3.Qxg2, 2…g1(Q), etc. 3.Qa1). Black defends by promoting the g-pawn – which self-blocks g1 – and this gives rise to three distinct variations. After 1…g1(Q), 2.Rg3 prevents 2…Qxg7/Qg5+, forcing 2…Qxg3/Qg2 3.Qa1. If 1…g1(B) seeking stalemate, then 2.Rc4 bxc4 3.Qa1. And after 1…g1(S), only the waiting move 2.Bxb5 could deal with the knight check, 2…Sf3+ 3.exf3, and also 2…Sxe2 3.Bxe2. Unfortunately, multiple duals follow 1…g1(R) when 2.Rg3/Rb3/Ra3/Qa7 are all effective, so the problem doesn’t quite achieve an Allumwandlung. Nevertheless, this is a splendid problem with a difficult key and surprising play, including the extra variation, 1…Kg1 2.Qa7 Kf1 3.Qa1.

George Meldrum: A pleasing array of play. The pawn promoting to a bishop almost got me.
Thomas Thannheiser: Very nice!
Jacob Hoover: I wonder if there's any way to remove the duals without completely wrecking the problem…