Here is one of the most famous problems of all time maybe one of the first Rukhlis themes. The beautiful problem also shows two Grimshaws.  There is a set Grimshaw:

1...Rc4 2.Sc3
1...Bc4 2.Qe4

Notice that these mates depend on the mutual interference of the bB and bR but also on wPd3 which is blocking the lines of the bBb1 and bRh3. The key is obvious to me - anytime I see this wR and wP combination the pawn push is always the first thing I try, especially considering the potential pins on d4. However, the key has two interesting effects that usher the changes and transferences: it opens the lines of bBc1 and bRh3 but closes the lines of bRa4 and bBh8, sort of an anti-Novotny and Novotny combination.  Now the captures on c4 are self-pins and the original Grimshaw mates from d4 are transferred to a new Grimshaw on d3. Beautiful.

1.d4! (>2.Sb6)
1...Rxd4 2.Sb4
1...Bxd4 2.Sf6
1...Bd3 2.Sc3
1...Rd3 2.Qe4

Here is one of my favorite Rukhlis problems of all time complete with cross checks, battery play, and a wR cross. The problem is an ideal Rukhlis in the sense that there are mates set for all of the thematic defenses.  There are four prominent set mates that are all changed post key

1...Rxe2 2.Re5
1...Se5 2.Rf6
1...Qa3+ 2.Re7
1...Sf6 2.Sd6

1.Sf2! (>2.Qg4)
1...Rxe2 2.Rf6
1...Se5 2.Qxe5
1...Qa3+ 2.Rd6
1...Sf6 2.Re5

Here is a famous ideal Rukhlis by one of the greatest two-move composers of all time. The set mates all display dual avoidance, particularly 1...c3 and 1...e2 which display a special kind known as Mari dual avoidance. 

1...c3 2.Sxe3
1...e2 2.Sb4
1...Sc6 2.Rd6
1...Sf5 2.Rf5

The excellent flight giving key now changes all four of these mates:

1.Se6! (>2.Qd1)
   1...c3 2.Rd4
   1...e2 2.Qd4
   1...Sc6 2.Sxe3
   1...Sf5 2.Sb4
   1...Kd6 2.Sc7

​And Sc7 is icing on the cake. 

Speaking of Mari, here is a gorgeous example of the theme with a royal battery and additional changes.  

1...Be4 2.Ke2
1...Bxd3 2.Kf3
1...Sc3 2.Qa7
1...d5 2.Qc5
1...Sb7 2.Qc4

1.Sc5! (>2.Qxd5)
   1...Be4 2.Rxe4
   1...Bxd3 2.Rxd3
   1...Be4 2.Ke2
   1...Sc3 2.Kf3
   1...Sb7 2.Sb3
   1...d5 2.Se6
 

In this excellent problem we have a Rukhlis with beautiful cross-checks and black correction.  

1...Bd~+ 2.Se6
1...Sc~+ 2.Se2

1.Sxe5! (>2.Sc6)
   1...Bd~+ 2.Sg6
   1...Sc~+ 2.Sd3
   1...Bxe5+ 2.Se6
   1...Sxe5+ 2.Se2
   1...Kxe5 2.Qc3

This problem shows the record setting Rukhlis with four transferred and changed mates. Perfunctory key is justified by the fact that it grants two checks on the wK.

1...fxe6 2.Sd7
1...Se5 2.Be7
1...Rg5 2.Rxf7
1...Rf3 2.Sxd5

1.Qxd5! (>2.Qf5)
   1...fxe6 2.Qxe6
   1...Se5 2.Qxe5
   1...Rg5 2.Qxg5
   1...Rf3 2.Se4
   1...Qd7+ 2.Sxd7
   1...Qe7+ 2.Bxe7
   1...Qxc5 2.Rxf7
​   1...Bxd5 2.Sxd5

Another wonderful ideal Rukhlis with white interference mates, white correction, and try play.

1...exf6 2.Sc2
1...f3 2.Sb3
1...Sc4 2.Rxc4
1...Sd3 2.Rxd4

1.Se~? (>2.Qe5)
    1...Qh5 2.Qg1
    1...Sd3!

1.Sg4? (>2.Qe5)
   1...Qh5!

1.Sc4! (>2.Qe5)
   1...exf6 2.Qxf6
   1...f3 2.Qe3
   1...Sc4 2.Sc2
   1...Sd3 2.Sb3
   1...Qh5 2.Qg1
   1...Sd5 2.Qxg5

At first glance it seems like the wBf8 is not used post key, however, this is not true it guards c5 after exf6.

Here is one of my own with a half-battery + additional battery formation idea.  Interestingly, my problem does not fit the usual mold for a Rukhlis, because the mates after the two thematic defenses are changed but not transferred. However, my problem does have two changed mates and two transferred mates:

1.Sxe5? (>2.Sxg6)
   1...Rxd7 a 2.Sa2 A
   1...Rxh1 b 2.Sa6 B
   1...Sxe5 c 2.Bxe5 C
   1...Sg2 d 2.Qxd5 D
   1...e2!

1.Sxd5! (>2.Sf4)
    1...Rxd7 a 2.Sa3 X
    1...Rxh1 b 2.Sa5 Y
    1...Se7 x 2.Bxe5 C
    1...Sxd5 y 2.Qxd5 D
    1...Sg2 d 2.Sf6

Notice that the mates A and B are not transferred, because of this it is what might be called an extended Rukhlis.

A fresh prize winner from the most recent World Cup for composing.  

1..Q~/.Qxg4 2.Sf6
1...dxe5 2.Sc3
1...Qf4+ 2.exf4
1...f2 2.Qh1
1...Qxe3 2.Qxe3

1.Qg3! (-)
   1...Q~ 2.Qf4
   1...Qxg4 2.Qg4
   1...dxe5 2.Qxe5
   1...Qxe3 2.Sf6
   1...f2 2.Sc3
   1...Qx53 2.Bxf5
   1...c4/cxb4 2.Rd4

It's a very nice problem but I do have some criticism.  My main complaint is the wSb4 which really has no post key function other than holding up the bPb5.  It does offer a try 1.Sc6? which contains a Dombrowski paradox, but it has an obvious refutation: 1...b4! I personally would remove -wSb4,bPb5 and shift wBd7>d8 (otherwise the matrix would be cooked by 1.Ba4).  Now-a-days it seems that problemists try to pack as much as possible into their matrices. I'm all for this, but I have strict belief of not adding material that will be useless just to create tries.  

Finally we end with a masterpiece that not only shows an ideal Rukhlis, but also the task of four changed self-blocks.  

1...Rxe6 2.Rxd4
1...Sxe6 2.c4
1...Qxe5 2.Qb3 
1...Sxe5 2.Sf4

1.Qg4! (>2.Rc5)
   1...Rxe6 2.Qxd4
   1...Sxe6 2.Qe4
   1...Sxe5 2.Rxd4 
   1...Qxe5 2.c4

Here's a perfect Bakcsi gem starter with a double flight gift in try and key.

1.Sxd5? (>2.Rd1)
  1...Kd3 2.Sf2
  1...Kxd5 2.Sc3
  1...Bd6!

1.Sxc5! (>2.Qb4)
  1...Kc3 2.Sxd5
  1...Kxc5 2.Sd3
​  1...Bxc5 2.Qe5

David Shire refers to the 1960s as the decade of the half-battery and this author was one of the pioneers.  Here is his famous changed wK X flight.  The wK has all 4 diagonal flights which can be handled by the respective R+B or R+S batteries.  So which one will do the job?

1.Sc3 (-)
   1...Kf3 2.Bd5
   1...Kxf5 2.Bd3
   1...Kh5 2.Be2
   1...Kh3 2.Bf1
   1...d5!

1.Bd5 (-)
   1...Kf3 2.Sc3
   1...Kxf5 2.Sxd6
   1...Kh5 2.Sxf6
   1...Kh3 2.Sf2

In addition to the nice four changes, the problem has a nice reversal of key and variation mate after 1...Kf3.

Here is one my own half-batteries, which might be called a third battery.  Notice the bK has an unprovided flight with 1...Kxd5, but in capturing this piece he will clear the d-file leading to a battery mate.  I am quite fond of this idea.  This one came together nicely and I still remember the moment when I figured out that the bPc5 with its two defenses was the key to the whole composition.

1.Sb3? (>2.Qxc5)
  1...Kxd5 2.Be3
  1...Rc3 2.Bf4
  1...c4 2.Bb4
  1...Sd7!

1.Bb4! (>2.Qxc5)
  1...Kxd5 2.Sxf3
  1...Rc3 2.Sf5
  1...Sd7 2.Sb5
  1...cxb4 2.Qc6

​

This half-battery uses a complex combination of Goethart and anti-Goethart strategy.  That is the threat by the half-battery can unpin the bRd3 because of the bP on e3.  However, when the bP moves this is no longer available.

1.Sfg5? (>2.Sd2)
  1...e2 2.Sd6
  1...Rc4 2.Sc3
  1...c5!

1.Seg5! (>2.Sd2)
  1...e2 2.Se5
  1...Rc4 2.Sd4
  1...Kc4/Rxg2 2.Qc5 
  1...Rd4 2.Rxd4
  1...c5 2.Qe4

Here I use the half-battery to obtain a record.  This problem shows four changed double checkmates which seems to be new!  I was pleased with the threat and the refutation.  The downfall is the number of black duals which were inevitable for this position.

1.Rg7? (>2.Sxb8)
   1...Kb7 2.Rb3
   1...Kd5 2.Rd3
   1...Sd6 2.Rc3
   1...Sc7 2.Rf6
   1...B any 2.Qa8
   1...Se3!
1.Rf7 (>2.Sxb8)
   1...Kb7 2.Rb2
   1...Kd5 2.Rd2
   1...Sd6 2.Rc2
   1...Sc7 2.Rg6
   1...B any 2.Qa8

The one downfall is that the B+R+R battery is extremely well-worked and I was lucky to obtain something new here.

Here is an indirect half-battery: the battery line is not pointed at the bK but rather an adjacent square.  The problem also shows the so-called bK Schiffman strategy in which the threat will unpin a bK and hence uses a different mate that exploits the pin.

1.Sdc1? (>2.Sf4)
   1...Kc4 2.Sc3
   1...Bxe2 2.Qe4
   1...Be6!

1.Sec1! (>2.Sf4)
   1...Kc4 2.Sxb4
   1...Bxe2 2.Qe4
​   1...Be6 2.Bg2

A beautiful combination of half-battery and Novotny. I like the changed mates and changed threats.  

1.Rd3? (>2.Rxa6/Sxc2)
  1...Sxb4 2.Qxa2
  1...Sxc6 2.Sbxc6
  1...Bxd3 2.Sxc2
  1...Rxd3 2.Rxa6
  1...cxb4!
1.Sd3! (>2.Rxc5/Rxc2)
  1....Sxb4 2.Rxa2
  1....Sxc6 2.Saxc6
  1...Bxd3 2.Rxc2
​  1...Rxd3 2.Rxc5

We end with a true masterpiece which took first prize in the competitive Mansfield memorial tourney.  The problem, like one above, combines the Schiffman strategy with half-battery.  However, this one achieves two changed Schiffman mates.  The idea is that 1...Sxb6 and 1...Rxb6 are self-pins that defeat the threat because it will unpin these pieces, however White can exploit these pins. There is an additional change after 1...Sd3. Even the interference battery mate 2.b7 is beautiful.

1.Bxf5? (>2.c5)
   1...Sxb6 2.Sf6
   1...Rxb6 2.Se6
   1...Sd3 2.Rxd3
   1...Sd6 2.b7
   1...Rd6!
1.Se3! (>2.c5)
   1...Sxb6 2.Be6
   1...Rxb6 2.Bxc8
   1...Sd3 2.Sc2
   1...Sd6 2.b7
   1...Bg8 2.Sxf5

One of my all time favorites and a fitting memorial problem for the great two move expert.

Here is a nice open light starter.  Capture of White has always been a popular helpmate theme and can be paradoxical.  After all, how does capturing white material help white eventually mate.  Here is an example with model mates. Remember, in helpmates Black moves first and then White mates.

1.Qxe2 Bd6 2.Ke8 Bc6
1.Qxh2 Re7+ 2.Kd6 Sf5

I like the roles of wBb7 and wSh6 which take turns mating and guarding the mating net. The mates are model mates with each square surrounding the bK being guarded or blocked exactly once.

This is one of my more heavy-hitting affairs that features the Zilahi theme. In the Zilahi theme a piece that is captured in one solution delivers mate in the other and visa-versa. The problem also features a rich strategy with additional captures, pin-mates, and switchbacks.

1.Bxg6 Rxd6 2.Kxe5 Re6
1.Sxe6 Bxh5 2.Kxf5 Bg6

This theme is also called an extended Zilhali with the  additional captures.  A couple of comments.  Overall I was very pleased with the position and realization of the idea.  However, the black economy is not ideal. bSe8 is a plug, bRh7 is a cook stopper, and the bQ is sort of a weasel-it could be replaced by a bP.  I kept the bQ to keep the matching strategy between solutions.  
​

​Now for something beautiful from the expert who wrote the book on helpmates.  Perfect harmony in which the pinned black pieces pass through the bK's initial square to open lines and unpin the mating piece. How I love the ambushes and the mates on the same square.

1.Kd4 Bb8 2.Rc2 Rxd3
1.Kc4 Rb8 2.Bg1 Bxd3

​

Here is an attractive half-pin scheme featuring 3 different half-pins and beautiful line play.

​1.Re4 Bxc7 2.Bg7 Sxe4
1.Qf2 Sxf7 2.Bg6 Bxf2

It is worth careful study to understand what makes this work.

Now moving onto the longer helpmates with an excellent example from the British grandmaster. This problem uses the Forsberg twinning method to obtain two solutions. I love the clearance moves with switchbacks to self block.

(a) 1.Rc3 Be4 2.Rc2 Rb3 3.Rc3 Rb4

(b) 1.Bd5 Rd3 2.Be6 Bb7 3.Bd5 Ba6

​



​

Here is possibly my best helpmate that features reciprocal batteries.  In one solution the a R+B battery is formed and the other has a B+R battery.  I was happy with the cooperation between Black and White.  All of Black's moves have departure and arrival effects.

(a) 1.Re5 Bh7 2.Sb5 Bd3 3.Se6 Be4
(b) 1.Bd6 Rf1 2.Sc6 Rf7 3.Sd4 Rf5

Here is a play-by-play recap of the strategy. The first move of Black has two functions: self-block and open a line. White then directly unpins one of the bSs to self-block again.  However, Black needs a piece on this newly vacated square so now White must indirectly unpin the other bS to replace his counterpart.   White ends by finishing off with a double check.

Here is a masterpiece that Chris Feather says 

"...the best problem in this book, shows White imitating Black in an equal but opposite way at every turn."

It's a single line long helpmate which you don't see too much now-a-days but exquisite play.

1.Bc4 Bh6 2.Bg5 Bd5 3.Be7 Bf3 4.Be6 Bf4

Here is a recent prize winner by an expert at light weight long helpmates.  The theme of the tourney called for two lines with White's first and last moves interchanged and two of Black's pieces self-block in one line and are captured in the other. Quite a task in a long helpmate.  See for yourself.

​1...Sg5 2.Re4 Sxe4 3.Kc4 Sxc3 4.Kb4 Kc2 5.Ka3 Bf8
1...Bf8 2.Qg7 Kc2 3.Rf6 Kd3 4.Ke6 Ke4 5.Qd7 Sg5

Here is a single line helpmate that features a nice withdrawal and so called indian theme. A nice sequence in a sub-miniature.

1.b5 Ra7 2.Bb6 Ra1 3.Kb7 Kb2 4.Ka6 Ka3 5.Ka5 Kb3

Finally we end with one of my favorites.  Another sub-miniature with airy construction and a pair of rook promotions. 

​1.h3 b8=R 2.h2 Rxb2 3.h1=R+ Rh2 4.Sb2 Rh3 5.Rb1 Ra3

Starting out with one of my own compositions.  I find this to be a beautiful Meredith with an open position and mirrored bK.  The mechanism is based on self blocks and dual avoidance with interference mates.  Notice that the wB on h6 is not doing anything.  Its two moves provide try and key.

1.Bg7? (>2.Rf5,e4)
​  1...Rc5 2.Rd8
  1...Bc5 2.Bc6
  1...Rxe2!

1.Bf8! (>2.Rd8,Bc6)
  1...Rd4 2.Rf5
  1...Bd4 2.e4
  1...Rb6 2.Rc5

The point is that the moves to the squares d4 and c5 defend against the threats because they cut off guard to c4.  I was really happy with this, but unfortunately this mechanism has been used several times for the Odessa.

Here is a heavy but nice Odessa that got second prize in the prestigious FIDE world cup tourney in 2011.  The excellent try and key each open a potential line for White and close a line for Black.  It is worth close study to figure out what makes the whole thing tick.  Moreover this problem accomplishes the double threat Le Grand where the defenses are the same -- really hard to pull off.

1.Bc3? (>2.Sc5,Qd5)
  1...Rxf5 2.Qxf3
  1...Kxf5 2.Sf6
  1...Sd4!

1.Sg6! (>2.Sf6,Qxf3)
  1...Rxf5 2.Qd5
  1...Kxf5 2.Sc5
  1...Qxf2 2.Qd3

Here is an early version of the theme that involves unpinning motifs.  

1.Rg7? (>2.d8=Q,dxc8=S)
  1...Qb7 2.Qc5
  1...Qxb8 2.Qf4
  1...Sb6!

1.Rg6! (>2.Qc5,Qd4)
  1...Se7 2.d8=Q
  1...Be7 2.dxc8=S
  1...Qxf5 2.Sxf5
  1...Qb5 2.Sxb5

Here is Mansfield composing at age 76 with a modern Meredith Odessa.  Beautiful royal battery and give and take keys.

1.Bd4? (>2.Qe5,Kc3)
  1...Kxd4 2.Qf4
  1...Bxd4 2.Kd2
  1...Rh2!

1.Be3! (>2.Qf4,Kd2)
  1...Kxe3 2.Qe5
  1...Bxe3 2.Kc3 

Here is an interesting double threat Le Grand.  I like this problem because it has a disappearing Novotny.  However, do you notice anything unusual? That's right, three white bishops!  Still pretty cool.  

1.Sd4? (>2.Rc2,Be2)
  1...Rxd4 2.Sb6
  1...Bxd4 2.b6
  1...e2!

1.Qxe3! (>2.Sb6,b5)
  1...Rd4 2.Rc2
  1...Bd4 2.Be2
  1...Rd6 2.Qc5
  1...Rxe3 2.Sxe3

​Here is the Odessa theme with triple threats. 

1.Rb5? (>2.Re6,Re7,Re8)
  1...Rf3 2.Rf5
  1...Rg3 2.Rg5
  1...Rh3 2.Rh5
  1...Sc5!

1.Re2! (>2.Rf5,Rg5,Rh5)
  1...Rc6 2.Re6
  1...Rc7 2.Re7
  1...Rc8 2.Re8

A rather symmetric position and the wQ acts as a bishop, but none the less quite an achievement in Meredith.

Here is the marvelous cyclic Odessa.  I have included the algebraic notation for clarity. The mechanism uses battery formations and an ingenious use of double checks. Dombrowskis really was one of the greatest twomove composers of all time.

​1.Qc8? (>2.Bb6 A, Bd6 B)
   1...Rxa6 2.Rc4 C
   1...Bxa6 2.Rd5 D
   1...Bc6!
​1.Qg1? (>2.Rc4 C, Rd5 D)
   1...e3 2.Sxd3 E
   1...Qe3 2.Sxd7 F
​   1...Qe6!
1.Qg5! (>2.Sxd3 E, Sxd7 F)
   1...Rb6 2.Bxb6 A
   1...Bxg5 2.Bd6 B
   1...Rxa6 2.Rc4 C
   1...Bxa6 2.Rd5 D
Note he also works in the mates C and D as variations post key.  Truly excellent!




​

Here is what I believe is the first example of the le Grand theme by the brothers themselves. The mechanism is simple enough and revolves around the wQ placing extra guard on the squares c4 and c6 while at the same time cutting the bQ or bB lines. There is also has a nice black correction element to the problem.

1.Qe4? (>2.Rc4)
  1...Sf6 (any random move) 2.Rc6
  1...Qxe4 2.Sxe4
  1...Sb4 2.cxb4
  1...Se7!
1.Qe6! (>2.Rc6)
  1...Sf6 2.Rc4
  1...Bxe6 2.Sxe6
  1...Se3 2.Sxd3
  1...Sxb6 2.Bxb6

There are some flaws in the matrix. For one, the duals after 1...Sxb6 and 1...Se3 in the try and dual after 1...Sb4 after the key. I guess these are forgivable in this correction scheme though.

Here is a classic le Grand featuring changed play. The mechanism uses a common means of a line opening of an ambushed piece.  Notice the wBc8 has a masked guard on f5 and g4: this is the essence of the mechanism.

1.Rg5? (>2.Qf5)
  1...Rxa7 2.Rg4
  1...Bg3 2.Qf2
  1...Sd4 2.Qc1
  1...Se3 2.Qxe3 
  1...Sxg5 2.Qxg5
  1...Bxe4!

1.Qh5 (>2.Rg4)
  1...Rxa7 2.Qf5
  1...Bg3 2.Rf3
  1...Sd4 2.e3
  1...Se3 2.Bxe3

The try has a little bit more play but four changed mates in addition to the le Grand is excellent!

Here is one of my more complex affairs.  The problem is pseudo le Grand, meaning the reciprocal change of threat/variation occurs after different defenses.  However, the point of this problem lies in the additional content of white correction, Barnes theme, and the threat avoidance.  

1.Sc2? (random move) 2.Qd4,Qxh1
  1...Qxf6!

1.Sf5? (>2.Qxh1 {Qd4?})
  1...Bf3 2.Qd4
  1...exf5 2.Qd5
  1...Qxf6 2.Sxd6
  1...Sxf5 2.Bb7
  1...Bg2!

​1.Sb5! (>2.Qd4 {Qxh1?})
  1...Sd3 2.Qxh1
  1...e5 2.Qd5
  1...Qxf6 2.Sxd6
  1...Sxb5 2.Bb7
  1...Sb3 2.Qc2
  1...Bb6 2.Sxc3

A random move of the wSd4 creates a double threat of Qd4,Qxh1. However, White must  compensate for the defense 1...Qxd6. To do so the wS must cut the line of either the wRf6 or the wBa6.  In turn, this reduces the double threat because the wQ must keep guard on d3 or f3 in her threatened mate.  The avoided threats reappear after self-blocks. Overall I was pleased with the matrix, but there are quite a few black duals (e.g. 1...Sb3,Se2 2.Qc2 and 1...Sxb5,Sf5 2.Bb7) which detract.  No white pawns!

The le Grand theme in-itself has little room for originality. This problem shows an exciting combination with two different reversals: the le Grand which is a reversal of threat and variation and the reversal 1 which is a reversal of first move/variation.  This is also known as the Lender combination.  Here we have a half-battery that makes things happen.  The pattern is the following:

1.A? (>2.X)
  1...a 2.Y
  1...b 2.B
1.B! (>2.Y)
  1...a 2.X
  1...b 2.A

1.Bxe4 A? (>2.Qa3 X)
   1...Kxb4 a 2.Qb2 Y
   1...Qxb4 b 2.Bc1 B
   1...a3 2.Qb3
   1...Qd5!

1.Bc1 B (>2.Qb2 Y)
  1...Kxb4 a 2.Qa3 Y
  1...Qxb4 b 2.Bxe4 A  
  1...a3 2.Qb3

This is known as a king's le Grand because the le Grand happens after a bK flight.

These last two problems are taken from David Shire's article on the le Grand in the March 2011 issue of the Problemist Supplement.  In this problem the out-of-play wRb6 makes two relevant tries showing the le Grand theme.

1.Rd6? (>2.Rc3)
  1...Sxd4 2.Ba6
  1...Rg8!
1.Re6? (>2.Ba6)
  1...Sxd4 2.Rc3
  1...Se5!

The author has put a new spin on the idea and now the threaten mates reappear as variations in the actual play with a beautiful flight giving key.

1.Se2! (>2.Sxf4)
  1...Sh3 2.Rc3
  1...Kxe2 2.Ba6
  1...Bxe2 2.Rxb3
  1...Rg4 2.Qxf3

​Excellent construction.

Here is a recent le Grand by one of the top contemporary composers. There are some nice changes and battery play combined with the le Grand.  In addition the problem shows the Ellerman-Makihovi theme in which a set dual is separated between try and key.

1...Ke5 2.Sxd6,Sd3

1.Bc8? (>2.Sxd6)
  1...Ke5 2.Sd3
  1...Qe5 2.Sb7
  1...e5 2.Qd5
  1...Rc7!

1.c3! (>2.Sd3)
  1...Ke5 2.Sxd6
  1...Qe5 2.Se4
  1...e5 2.Qd5
  1...g5+ 2.Sd3 (threat)

The key shows a White Goethardt, in the sense that the bBd2 can be unpinned because of interference. 

Finally we end with an excellent cyclic version of the theme.  The pattern is the following:

1.Try? (>2.A)
  1...a 2.B
1.Try? (>2.B)
  1...a 2.C
1.Key! (>2.C)
  1...a 2.A

1.Rf3? (>2.Rg5)
  1...Bxe4 2.Shg4
  1...Rxg7!
1.Qb3? (>2.Shg4)
  1...Bxe4 2.Sfg4
  1...Bd5!
1.Re3! (>2.Sfg4)
  1...Bxe4 2.Rg5
  1...Bd7 2.Sf7
  1...dxe3 2.Qb2

Here is the first problem (even though it was published after the second problem, it was composed first).  I love the open position that features a mirrored bK.  There is set play that won't full anyone but the most inexperienced solvers: 1...Sf8~ 2.Qxe6, 1...Qd5 2.Qxd5.  However, there is no set mate for 1...QxQ.  While this seems to enable the R+S battery by unpinning the lead piece, it actually does not because the wS is guarding c5.   This gives a hint to the key:

1.Qh5! (>2.Qe2)

So the wQ unpins the bQ. Now the bQ is on the loose and does some damage.  However, the wQ also places guard on c5 enabling the R+S battery.  The play follows:

1...Qb6+ 2.Sc5
1...Qh3+ 2.Sg3
1...Qd7,Qd6 2.S(x)d6
1...Qxe4+ 2.Rxe4
1...Qd5 2.Qxd5
1...Sc5 2.Qxc5
1...Bd1 2.Qb5

Overall, a pleasing problem with a thematic key, cross-checks, and battery play.  However, there is one fly in the ointment: the minor dual after 1...Qg4 2.Qd5/Sd6.  This dual is inevitable and it is not worth adding material or losing variations over it.  Besides, these mates are separated in other variations.  

As with any traditional problem there is always a high risk of anticipation. Barry Barnes commented on my problem that the cross-checks had been shown before, but none that he knew of with such a thematic key.  It turns out there are some problems that use a half-pin to show these batter mates (see this problem yacpdb/26o53).  However, it turns out one does not have to look too far to find a similar problem. 12 years earlier the following problem appeared in the same source.  The excellent step back key sets up similar variations:

1.Qf8! (>2.Qh6)
1...Qxf8+ 2.Sf7
1...Qc2+ 2.Sd3
1...Qe7 2.Sc4
1...Qxe5+ 2.Rxe5
1...d3 2.Qxc5
1...Sd3 2.Re2

It's hard to say which problem is better.  On the one hand all of this problem's mates are in the set play.  On the other hand there is no dual.  However, I probably would rank this problem a little higher due to the two nice tries which show the Barnes theme:
1. Qf6? (>2.Qg5,Qh6) d3!
​1.Qe7 (>2.Qg5) h6!

Here is the second problem that I composed around the same time.  This time I used a R+B battery. The position is even more attractive with no pawns and a mirrored bK again.  All of the play is set and all the wQ must do is position herself to make the threat.

1.Qb7! (>2.Qh7)
1...Qe8+ 2.Bf7
1...Qb7 2.Bxb7
1...Qxd5+ 2.Qxd5
1...Qc4,Qb4 2.Be4
1...Rb4 2.Rc4

The problem is pleasing with three nice battery mates, but there is less play and the key is rather perfunctory and is missing that element of surprise.  Ideally, I wanted to start the wQ at a6 for a nice unpinning key similar to my above problem.  However, if we do this (wQa8>wQa6) then the bR is doing double duty guarding both c3 and b5 and so 1.QxQ cooks.  So I submitted the problem as is and it appeared in the high quality French journal Phenix.

​It occurred to me that there is an amazing simple improvement that improves the key AND adds an extra thematic variation (a fourth unpin of the wB), all while maintaining the aristocrat Meredith status.  The key now unpins the bQ letting her do some damage. The added variation is a fourth unpin of the wB this time an indirect unpin:

1.Qb7! (>2.Qh7)
     1...Sc5 2.Bb3 

With the rest of the play remaining the same.

Here is another pawnless wonder that is quite possibly one of my best.  You will notice the arrangement of the the three pieces that stand between the wB and bK.  At first glance this looks to be a half-battery idea similar to those found in the last blog post.  However, it is not, because the same lead piece moves first in each phase.  Instead what we have is known as the Makihovi theme.  There is a set dual: 1...Bc3 2.Sb6,Se3.  Try and key separate this dual and interchanges the two mates between the phases.

1...Kxd5 2.Qa2,Qb3
1...Bc3 2.Sb6,Se3

1.Rb6? (>2.Qb3)
   1...Bc3 (Bb2) 2.Se3
   1...Kxd5 2.Rf5
   1...Bxb6 2.Sxb6
   1...Sb5 2.Qxb5
   but 1...Rf3!

1.Re3! (>2.Qb3)
   1...Bc3 2.Sb6
   1...Bb2 2.Qd3 
   1...Kxd5 2.Rf6
   1...Bxe3 2.Sxe3

The variations 1...Bc3 2.Sb6, 1...Bb2 2.Qd3 exhibit an idea known as dual avoidance.  Namely, after the key is played if one were to just remove the bB from the board there would be two mates 2.Sb6 and 2.Qd3, i.e., a dual. These two mates come from the fact that moving the bB has two errors: opening unguarding b6 and opening the line of guard from d3 to d5. However the two defenses 1...Bc3 and 1...Bb2 only allow one of these mates. The reason is that even though both of these moves make the two errors, they have a compensating effect that only allows one of the mates.  
 

So what is the improvement?  Despite thinking about this problem for a long time, I was not able to reduce it to the Meredith status: 12 pieces.  That is, I did not think I was able to do so, until I looked at the solution in the July Problemist and it dawned on me that the bR can be moved either to f2 or f5 to get rid of the cook 1.Rxf4!  which was the original reason for the 13th piece bSh3.  I have placed the bR at f2 because this also rids the matrix of the parasitic try 1.Sc1 (>2.Qb3) which was present in the first matrix.  I really wish I would have spotted this before publishing!

Here is another problem that I was able to fiddle with for a possible improvement.  The problem is by the great Spanish composer and inventor of the theme bearing his name.  This particular problem is a traditional fair with battery play and three changed mates after the bK flights:

1...Kf5 2.Qg6
1...Kd3 2.Bxc2
1...Kf3 2.Qxa8

1.Rxc2! (>2.Rc3)
1...Kf5 2.Rb7
1...Kd3 2.Rg2
1...Kf3 2.Qg2
1...Be3 2.Rf2
1...f3 2.Rb4
1...bxc2 2.Bxc2

Lovely battery play and even though it is by-play my favorite mate is white interference mate 2.Rf2.  

One thing that bothers me about the Salazar is the wRa3.  Sure, this rook does pull its weight in both the set and actual play. But it is an expensive luxury.  One thought is to just remove it and bPb3, but then 1.Bxc2+ cooks.  However, with some adjustment one arrives at the following matrix.  Is it worth it?  The extra wR is removed, but now the set mate for 1...Kf3 is lost and this flight is unprovided.  

Here I am up to my old tricks.  One of my favorite ideas is the changed check in which White gives up a set check by exploiting a pin. In this problem the idea is coupled with promotion play.  There are some nice tries  by unpinning the lead battery piece, but the key requires something more subtle.

1...Qxf7+ 2.Bxf7

1.Ka6? (K~) (>2.f8=S)
  1...Qf8!

1.Sb5? >2.Sc7
  1...Bf4!

1.Se8! (>2.Sc7)
  1...Qxf7+ 2.Sc7
  1...Qg3 2.f8=S
  1...Qe5 2.f8=Q
  1...Qxg8 2.fxg8=Q
  1...Bf4 2.Sxg7

Here is a perfect example with a half-battery by the master of the 7th rank.  

1.exf7? (>2.f8=Q)
  1...Bg6 2.g8=S
  1...Bg8 2.fxg8=S
  1...Qg4 2.dxe7
  1...Qd5!

1.dxe7! (>2.e8=S)
  1...Qd8+ 2.exd8Q
  1...Bxf5 2.g8=S
  1...Qg4 2.exf7
  1...Qd7 2.fxd7
  1...fxe6 2.Qxe6

Three different promotions in each phase, the best play saved for last with two battery mates, and reversal of key and variation after the defense 1...Qg4.  Yes please.

The famous Bettman task of 6 promotions.

1.Rd7! (>2.c8=Q,cxb8=S,cxd8=S)
   1...Kc8 2.cxd8=Q
   1...Kxa7 2.c8=S
   1...Sxc6 2.cxb8=Q
   1...Kxc6 2.cxb8=S
   1...Se6 2.c8=Q
​   1...Rc8 2.cxd8=S

Lovely promotion play in a miniature. Excellent changes from set play and a wonderful flight giving key. Doesn't get much better than this in a miniature. 

1...Rf8+ 2.gxf8=Q
1...Rxg7 2.Rh8

1.Rg6! (>2.Rh8)
   1...Rxg7 2.Rgxg7
   1...Rf8+ 2.gxf8=S
   1...Kxg7 2.g8=Q

Who doesn't love the promotion mate on the initial bK square!

Here is a problem that was in a recent tourney which I took part in.  I really thought it was excellent total change composition. The choice between a wQ or wS promotion with change of 4 mates.  It's nice that the weaker piece, the knight, wins out.

1.e8=Q (-)
  1...Rxc3 2.Rxd5
  1...Sh~ 2.Qf5
  1...g6 2.Qh8
  1...cxb6 2.Qb8
  1...Rd4 2.cxd4
  1...Bg1!

1.e8=S (-)
  1...Rxc3 2.Bxc3
  1...Sh~ 2.Qe4
  1...g6 2.Qf6
  1...cxb6 2.Bd6
  1...Rd4 2.cxd4
  1...Bg1 2.Qxg3

Here is a light problem with the Fleck theme.

1.e7! (>2.exd8=Q,S,exf8=Q,S)
  1...Rd~ 2.exf8=Q
  1...Rf~ 2.exd8=Q
  1...Rxb8 2.exf8=S
  1...Rxg8 2.exd8=S
  1...Rc8+ 2.bxc8=Q

Finally we end with a masterpiece.  Analogous to the Bettman problem above it shows 6 promotions of a single pawn.  The motivations for the promotions are similar, but this one is so much better. Completely accurate with a flight giving zugzwang key, a changed mate, and an extra promotion mate for good measure.  

1...Kf8 Rxf7

1.exf7! (-)
  1...Kf8 2.fxg8=Q
  1...Kf6 2.fxe8=S
  1...Kxd7 2.f8=S
  1...d5 2.fxe8=Q
  1...Bh7 2.f8=Q
  1...Rf8 2.fxg8=S
  1...Rxd8+ 2.cxd8=Q
  1...S~ 2.Qxd6
​  1...Bxf7 2.Rxf7

Here is a light starter of my own to give an idea what the disappearing Novotny is about.  

1.Bg6! (>2.Bg7,Rh7)
   1...Bxg6 2.Qf8 (Bg7?)
   1...Rxg6 2.Qh8 (Rh7?)
   1...Rb1 2.Bg7
   1...Rxa1 2.Rh7

Simple but satisfying.  The self-blocks are a common mechanism. The "disappearing" part of the Novotny, i.e., the reason that the threatened mates do not work is because of the loss of guard on h7.  Two points that I would like to make about this problem.  First  the threats are separately forced.  Second the mates after the captures of the key piece depend on the mutual interferences of the rook and bishop.

On to the heavy hitters with one of my favorite Dombrovskis problems.  While this is not a Zagoruiko, it does have the feeling of one. Indeed, there is a set Grimshaw:

1...Bd6 2.Sh6
1...Rd6 2.Se5

Then the key, which is strong because it pins the bB, sets off some wonderful changes.

1.Bd6! (>2.Rf4,Bc8)
   1...Bxd6 2.Qd7
   1...Rxd6 2.Qg1
   1...Sexd6 2.g8=Q
   1...Sbxd6 2.Be2
   1...Qxd2 2.Bc8
   1...Qc4 2.Rf4

Notice how the bQ is used to make the mate 2.Bc8 "disappear" after 1...Bxd6.

Here is another famous problem by one of the popularizers of the disappearing Novotny. This problem won first prize in the BCM tourney and is often cited as THE example of a disappearing Novotny.  The bK has a flight at c3 which is met by

1...Kc3 2.Bd2

The give and take key opens the lines of the wB and wR to threaten two wQ mates

1.Sb5! (>2.Qc5,Qxc4)
   1...Bxb5 2.Bc5
   1...Rxb5 2.Rxc4
   1...Kxb5 2.Qb6
   1...d5 2.Qc5
   1...d4 2.Qxc4

A lot going on in this wonderful problem, but I want to point out some of the things I like about it.  First there are several interactions of rooks and bishops. The key opens the wR and wB lines but closes the bR and bB lines.  Sydenham calls the opening of the two lines an anti-Novotny.  However, the move 1...Kxb5 also opens the lines of bBa3 and bBa4 giving kind of a Black anti Novotny.  So it has a true Novotny, a White anti-Novotny, and a Black anti-Novotny.  Several people have mentioned the role of wRh3.  It is used to provide for the set flight 1...Kc3, but it only has a minor role in one post-key variation to cover the square c3 after Bxb5.   

This is one of my favorites compositions. This problem actually sets the economy record for disappearing Novotny and does so in style with 10 pieces with no pawns!  Moreover, there is a nice changed mate from the set play, unique separation of the threats, a total defense, and a wonderful thematic withdrawal key.

1...Rf2 2.Sc5

1.Bf2! (>2.Rb6,Ra1)
  1...Bxf2 2.Qxf1
  1...Rxf2 2.Qc6
  1...Bb5 2.Bxb5
  1...Bc4 2.Rb6
  1...Rg6 2.Ra1

Unfortunately, as with many #2s, now a days the basic mechanisms were found to be partially anticipated by a Jac Haring problem (https://www.yacpdb.org/#468766).  I still managed to shave 3 pieces off to obtain the record.  

Here is one of my favorite problems and a little bit of a twist on the usual disappearing Novotny.  Notice the wP on c4 stands at the intersection of the bR and bB.  Moreover captures of this piece have set mates:

1...Rxc4 2.Rd6
1...Bxc4 2.Bb2
1...Kxc4 2.Qb4

The key changes all of these mates with a variety of effects.  It is worth close study to see why all of the mates are changed.  

1.Se4! (>2.Qc3,Qd4)
  1...Rxc4 2.Qd8
  1...Bxc4 2.Sc2
  1...Kxc4 2.Rb4
  1...Qxe4 2.Rxe4

This problem is actually a combination of two Novotny ideas: the Norwegian Novotny where the white piece already stands in the intersection and the disappearing Novotny. Such a combination is referred to as an Azerbaijani Novotny. I would opt to put a bR on h3 to force the threat 2.Qd4 with 1...Rxf3, of course this is a matter of taste.  

In my opinion this is a classic problem that deserves more recognition.  The use of the wQ as a Novotny piece is rare and this is an excellent rendering.  Here the Novotny captures are coupled perfectly with abandonment of rear guard, letting the wQ march in along the line to mate.

1.Qe3! (>2.Ra5,Sg3)
   1...Rxe3 2.Rc5
   1...Bxc3 2.Rh2
   1...Rxc4 2.Qh3
   1...Bxe1 2.Qxh6
   1...Bg4 2.Bf7
   1...Bc2 2.Ra5
   1...Ba4 2.Sg3

I like how the threat 2.Ra5 is forced by the bBd1. Outstanding!

An excellent little Meredith demonstrating the idea with pin-mates.

1.d4! (>2.Qe5,Sc4)
   1...Rxd4 2.Bf4
   1...Bxd4 2.Bb4
   1...Be6 2.Qf8

​Unfortunately the Qe5 threat goes unforced and I cannot see how to make it happen without breaking the Meredith economy.

Another delight with a regular Novotny try and a disappearing Novotny.

1.Se6? (>2.Qe5,Qd7)
   1...Bxe6 2.Qe5
   1...Rxe6 2.Qd7
   1...Sf6!

1.Be6! (>2.Qe5,Qd7)
   1...Bxe6 2.Sxe4
   1...Rxe6 2.c8=S
   1...Rb8+ 2.cxb8=Q
   1...Sf6 2.c5

Another Sydenham problem that I like.  The formation of the ambushed wQ is very common in disappearing Novotny problems, but what really makes this problem stand out is the the anti-cricitcal and critical play.  There two different pairs of threats but the disappearing mates remain the same.

1.Bf7? (>2.Sc4,Be7)
   1...Rxf7 2.Qd4
   1...Bxf7 2.Qd8
   1...c5 2.Be7
   1...g5 2.Sc4
   1...Rxh4!

1.Rf7! (>2.Sb7,Rd6)
    1...Rxf7 2.Qd4
    1...Bxf7 2.Qd8
    1...Bg3+ 2.Bxg3
    1...c5 2.Re6
    1...g5 2.Sb7

This problem is the famous changed disappearing Novotny. One of two problems to show the idea and the other problem has an unprovided checkmate! (see here)  It does have a flight taking key in part (b), but none-the-less a milestone.

(a) 1.Sdf3 (>2.Rc6,Rc1)
        1...Rxf3 2.Qxc7
        1...Bxf3 2.Qc2

(b) 1.Sgf3 (>2.Qh5,Qg1)
        1...Rxf3 2.Qe5
        1...Bxf3 2.Qf2

Finally a problem which is in the running for my best two mover.  There is relevant set play:

1...Bc6 2.Sc2
1...e1=S,B 2.Sf1

1.Sc6! (>2.Sc4,Ra3,Re6,Rf3)
   1...Bxc6 2.Qxb6
   1...Rxc6 2.Qe5
   1...bxa5 2.Sc4
   1...exf6 2.Ra3
   1...e1=any 2.Re6
   1...Sxc6 2.Rf3

That's right, a combination of the Fleck and disappearing Novotny theme with changes. Overall this came together splendidly.

We start with a recent 2nd prize winner from the "Newotny" theme tourney for the 80th birthdays of Barry Barnes, John Rice, Michael Lipton, and Colin Sydenham.  I liked this problem better than all of the entries because of how artistic it was.  On face value there are 3 Novotny cutting points: e5, e2, g7.  The try 1.Se5? (2.Qd4,Be6) falls to the line cutting defense 1...Sc3! The point is that refutation cuts the wB's guard on d4 and e5 which are both already covered.   The threat 2.Be6 cuts the wRe8's line of guard on e5 and hence will not work. Such a defense is known as a Theme A defense. So White now moves on to the other Novotny squares. However, play to these squares picks up an extra threat from the previous e5 try along with the natural threats.  This extra threat is enforced by other theme A defenses.

1.Re2? (>2.Qc4,Se3,Be6)
   1...Rxe2 2.Qc4
   1...Bxe2 2.Se3
   1...Bc3 2.Be6 
   1...Qd4 2.Qxd4
   1...c5!

1.Bg7! (>2.Sc7,Sf6,Qd4)
  1...Bxg7 2.Sc7
  1...Rxg7 2.Sf6
  1...Re7 2.Qd4
​  1...c5 2.Qb7

Who doesn't love theme A line cutting defenses? Beautiful open position and idea.  ​

Here is a traditional problem with the 6th WCCC theme of 3 pairs of related variations. 

1.Rf4! (>2.Rd5)
   1...Rxe5 2.Se6
   1...Bxe5 2.Qd6
   1...Rxe4 2.Qe3
   1...Bxe4 2.Sf3
   1...Bd8+ 2.Re7
​   1...Rg1+ 2.Bg2

A wonderful combination of the half-battery and Dombrowski paradox.  In the Dombrowski paradox a try that threatens mate (A) has refutation (a).  Meanwhile after the key the same defense (a) allows the mate (A).  Here we have the full on theme in threefold form.

1.Be3? (>2.Sh2)
  1...Rxe3 2.Sc8
  1...Rd8 2.Sd2
  1...Rxh1 2.Sc6
  1...Rd6!

1.Bh2? (>2.Se3)
  1...Re1 2.Sc8
  1...Rd6 2.Sd2
  1...Rxh2 2.Sc6
  1...Rd8!

1.Bb6? (>2.Sc8)
  1...Rxb6 2.Sh2
  1...Rxa8 2.Se3
  1...Re4!

What remains is to form a third battery!

1.Bd4! (>2.c4)
  1...Rd6 2.Sh2
  1...Rd8 2.Se3
  1...Re4 2.Sc8

This problem features one of my favorite two-move themes: the French-Russian.  The idea is that several tries are defeated because of the specific errors they cause.  However, the key compounds the errors, but compensates for them in some way.

1...Qxf3 2.Rxf3
1...Bxe7 2.Bd4
1...Sxe7 2.Qf4

1.Rg5? (>2.Sf5)
    1...Sd6 2.Sxd5
    1...Qxf3!
1.Rf6? (>2.Sf5)
    1...Bxe7!
1.Rf4? (>2.Sf5)
    1...Sxe7!

The tries fail because they unguard f3, block the wQs line to f4, and block the wBs line to d4 respectively.  The key does all of these things!  It provides for these defenses by pinning the bS.

1.Re5! (>2.Sf5)
   1...Qxf3 2.Qc3
   1...Bxe7 2.Rc4
   1...Sxe7 2.Bh6

Here is a delicious Meredith featuring a doubling of the so-called anti-switchback.  I love this author's switchbacks (see the March 2018 post) and here he adds a new wrinkle.  The double pawn push separates two different mates, one of which is a switchback.

1.Qd4? (>2.Bxa5)
   1...e6 2.Qf6 (switchback)
   1...e5 2.Qh4 (anti-switchback, Gamage unpin)
   1...Bxc3 2.Qb6
   1...Bc7!

1.Qc6! (>2.Qc8)
   1...e6 2.Bf6 (anti-switchback)
   1...e5 2.Qf6 (switchback)
   1...Rc5 2.Qd7
   1...Bc7 2.Qxc7
   1...Be6 2.Qe8

​Neat idea and perfect execution.

Another blockbuster.  The wQ is pinned and the wRf8 is ambushed behind the bBf7.  If the bB opens the line (e.g. 1...Be6) there are three mates 2.Bxf2,Bf4,Rxf3.  Moreover, if the wQ is unpinned there are three mates 2.Qd4,Qd3,Qd2.  The wRb2,wSc1,wPc3 can unpin the wQ but this cyclically forces only two of the mates.  Moreover, these moves separate the set dual.

1.Sb3? (>2.Qd2,Qd4 [Qd3?])
   1...Bxd5 2.Rxf3
   1...Sd~ 2.Sf5
   1...fxg2!

1.Rb3? (>2.Qd4,Qd3 [Qd2?])
   1...Bxd5 2.Bf4
   1...Rxc3!

1.c4 (>2.Qd3,Qd2 [Qd4?])
   1...Bxd5 2.Bxf2
  

A beautiful idea with tries that feature the same error.  The wSb4 looks to be the key piece but where should it go?  Don't miss the set checks handled by the battery play.

1...Be8+ 2.Sd7
1...Qf5+ 2.Bd5
1...Qf1+ 2.Bd3

1.Sc6? (>2.Sd8)
  1...Be8!
1.Sd5? (>2.Sc7)
  1...Qf5

These tries fail because they obstruct the batteries in some way and allow Black to pin the threat piece.  However, the key does the same thing, this time changing the set mate.

1.Sd3! (>2.Sc5)
   1...Qf1 2.Bg6
   1...Qf5+ 2.Bd5
   1...Be8+ 2.Sd7

Even his miniatures have depth.  In this problem we have a nice little try problem featuring a showdown between the wQ and bR.  At first glance one wants to move the wQ to threaten mates and there are lots of ways to do this. The most threatening move is 

1.Qg8? (>2.Qxg7,Qd5,Qg2,Qg1)
    1...Rh8 2.Qxh8
    1...Rg7!
1.Qf8? (>2.Qf3,Qf1)
    1...Rf7 2.Qh6
    1...Rg7!
1.Qe8? (>2.Qe4,Qe1)
    1...Re7 2.Qh5
    1...Rf7!
1.Qd8? (2.Qd5,Qd1)
    1...Rd7 2.Qh4
    1...Re7!

Now we have figured out that moving the wQ doesn't work, but moving the wB opens the line for the wQ.

 1.B~(Bb7)? (>2.Qc1)
     1...Rd7!

Finally White can handle this defense with

1.Bd4! (>2.Qc1)
    1...Rh8 2.Qxh8
    1...Rg7 2.Qh3

A wonderful duel between the wQ and bR.

Another experiment with the switchback and a fantastic one at that.  Not only a pair of switchbacks but a beautiful Zagouriko.

1...Qxg8 2.Bxe4
1...d3 2.Qxe4

1.Rxe4? (>2.Qe2)
   1...Qxg8 2.Re6 (switchback)
   1...d3 2.Re3 
   1...Sd3+ 2.Qxd3
   1...Sc3!

1.Sxe4 (>2.Qf1)
   1...Qxg8 2.Sf2 (switchback)
   1...d3 2.Sd2
   1...Sd3+ 2.Qxd3

​

Here is an outstanding achievement.  The try makes a triple threat and these mates return after a triple flight giving key as variations after the bK moves.  
​
1.Sg3? (>2.Qe4,Qxh6,Qc7)
   1...Sf5 2.Qxf5
   1...Sf3 2.Se2
   1...c3!

1.Sc3! (>2.Sd5)
   1...Ke5 2.Qe4
   1...Ke3 2.Qxh6
   1...Kg3 2.Qc7
​   1...Sf3 2.Se2

I always enjoy David Shire's problems and this one is no different. In this problem the innocuous twinning changes the strategy from a threat to a waiting problem.  Both solutions are very satisfying with a flight giving key and gate openings.  The problem also has a nice bit of detective work that must be done to figure out why one solutions hold in each part 

(a) 1.Sc3 (>2.Qc8)
     1...Kxc3 2.Qd3
     1...Rd5 2.Qxd5
     1...Rd6 2.Qb5

(b)  1.Ka4! (-)
      1...a5 2.Qb5
      1...Rd5 2.Qc2
      1...Rd3 2.exd3
      1...R~ 2.Sa3

Here is one of my earlier compositions and a nice little block problem at that.  The twinning is slightly unusual in that you have to solve part (a) before proceeding to (b).  (a) has a flight giving key while (b) is a complete block with with several obstruction tries and an added mate.

(a) 1.Bg4! (-)
         1...Ke4 2.Qxc4
         1...Sg~ 2.Sf5
         1...Bg2 2.Qxg2
         1...Bf3 2.Bxf3
         1...Be4 2.Be6

For part (b) the problem is a complete block so all White has to do is find a waiting move to hold the fort.

(b) 1.Ba8? c5!  1.Be3? Ke4! 1.Bf2? Bg2!
     1.Bg2! (-)
         1...c5 2.Qa8

Part (b) has a neat little key in which the wB is shuttled to the edge of the board without much effort.  Solvers commented that it could stand alone!

Here is another curiosity: the two kings are swapped.  It is interesting because the wK plays such a prominent role in the first part.

1.Rxc2! (-)
   1...Bd2 2.Kxd2
   1...bxc2 2.Kxc2
   1...Bxe3 2.Kxe3
   1...S~ 2.Ke4

1.Qc6! (-)
   1...Bd2 2.Re1
   1...Bxe3 2.Rxf2
   1...Bxb2 2.Sxb2
   1...S~ 2.Qg6
   1...Se4 2.Qc4

​Neat total change and battery play.

Something brilliant from the great composer.  A random move of the wK will threaten Rf8. Surely the type of piece on a3 can't determine the key move?!  Notice the set mate after castling          1...0-0-0 2.Qxc7, which uses the wBg2's guard on c7.

(a) 1.Kg1! (>2.Rf8)
(b) 1.Ke1! (>2.Rf8)
(c) 1.Ke3! (>2.Rf8) (Kg1 is a nice try here)

Now we come to the interesting part.  The only reasonable square for the wK to go is g3, but this destroys the set mate after 1...0-0-0.  However, castling is illegal!  Why?  Black has 7 pawns and the bBb3 is promoted.  This means that the bQ must have escaped her home square somehow and the only way is if the bK has moved.  Castling is illegal!

(d) 1.Kg3!

Not a lot of play but a beautiful and rich idea with a wK star.  The twinning mechanism is the so called Forsberg twinning in which a piece of different type is substituted.

This is a continual form of twinning in which the alterations are made to the new diagram.  In this particular case the procedure continuously removes pieces, giving the so-called strip-tease twinning. The problems are as follows:

(a) diagram
(b) remove a2
(c) further remove c2
(d) further remove b2
(e) further remove c3

(a) 1.Qd3!
(b) 1.Kd3!
(c) 1.Rc4!
(d) 1.Qa2!
(e) 1.Kd3!

Achieving sound problems in each part is amazing.

​

 
​This problem appeared next to one of my own (also a twin) in the British Chess Magazine.  Usually moving the bK is an unwanted form of twinning, but here we get a changed double Grimshaw.  

(a) 1.b8=S! (-)
         1...Be7 2.R6e5
         1...Re7 2.Sf6
         1...Be2 2.R3e5
         1...Re2 2.Bxf3
         1...Rxe6 2.Bxe6
         1...Rxe3 2.Sxe3
         1...c6 2.Rd6

(b) 1.Sf8! (-)
         1...Be7 2.R6e4
         1...Re7 2.Rf6
         1...Be2 2.R3e4
         1...Re2 2.Rxf3
         1...Rxe6 2.Sxe6
         1...Rxe3 2.Bxe3
         1...c6 2.Bd6

Remarkably there is a hidden task to this problem.  There seven pairs of mates on the same square.  The squares d6, e3, e4, e5, e6, f3, and f6 are all visited by two different white pieces for mate. I really like the interchange of functions between the bishops and the knights.

Another ingenious idea from the Hungarian Grandmaster.  Loyd introduced the excelsior in 1861 and this is a two move take on the idea.  One could argue to leave off (e) because of the repeated mate Qxf3, but I like the knight promotion coupled with the Q promotion in the previous part.

(a) 1.a4! Kxc6 2.Be4
(b) 1.a5! Kxc6 2.Qxf3
(c) 1.a6! Kxc6 2.Qc5
(d) 1.a7! Kxc6 2.a8=Q
(e) 1.a8=S! Kxc6 2.Qxf3

Another sparkling idea.  A bK shift leads to reciprocally changed mates between a Grimshaw with play to the same square.  The mechanism is a change between direct and indirect batteries.  Maybe the only flaw is the identical keys.

(a) 1.Ba6! (>2.Qd3,Qf4) 
   1...Bc4 2.Sc5
   1...Rc4 2.Bc5

(b) 1.Ba6! (>2.Qd3,Qe5)
   1...Bc4 2.Bc5
   1...Rc4 2.Sc5

Another classic from Mansfield that won first prize in the Problemist.  A stalemate release with lots of changes.

(b) wK>d7
(c) wK>g3
(d) wK>g5
(e) wK>f8
(f) wK>a3

​(a) 1.Bc3! Kc4 2.Ba2
(b) 1.Rf6! Ke5 2.Rf5
(c) 1.Rc2! Ke4 2.Rc5
(d) 1.Kf6! Kd4 2.Ke6
(e) 1.Bg6! Ke6 2.Be4
(f) 1.Bc2! Kc4 2.Be4

I wasn't going to include any helpmates in this post but this one is too good to pass up.  One of the most original ideas I have ever seen.  I am going to call this the time machine theme.  I have included the full algebraic notation so you can understand the idea.

(a) 1.Sd6-f5 Sd7-e5 2.Rc6-d6 Se5-f7 3.Bb5-d7 Sf7-d8
(b) 1.Bd7-b5 Sd8-f7 2.Rd6-c6 Sf7-e5 3.Sf5-d6 Se5-d7

Here is one of my original ideas that features board manipulation.  This is probably the heaviest position I have created but I think the idea is worth it.  The idea is that in the set play of (a) bPe6 controls the royal battery.  So it must be captured after the self pinning check.  After the key this square is now occupied.  When the board is inverted this strategy is reciprocally changed to the other pawn.  Between all of the variations and threats there is a wK tour.

(a)
   1...Sxf5+ 2.Kxe6
1.Bxe6! (>2.Kd7)
   1...Sxf5+ 2.Kxc6
   1...Sxe6 2.Kxe6
   1...Rxc5 2.Kxc5
   1...Sf6 2.Ke7
   1...Bxb6 2.Bxd2

(b)
   1...Sxf4+ 2.Kxc3
1.Bxc3! (>2.Kd4)
   1...Sxf4+ 2.Kxe3
   1...Sxc3 2.Kxc3
 
It's not a big deal but looking back I wish I would have rotated the board 180 degrees instead of reflecting it.  Why?  In terms of a physical chess board a rotation makes more sense.  After all, if you flip over a board then all of the pieces would fall off!

          

Another board manipulation problem.  I like the way manipulating the board affects castling.  This problem features a non-partial 4-fold Fleck in each part.  That is, each twin makes 4 threats and there are 4 unique moves that separate the threats. All other moves purposely give all 4 threats.  The only downfall is the flight taking key in (b).  Interestingly the key pieces play to the same square in each part.

(a) 1.Bg4! (>2.Kd2,Ke2,Kf2,0-0)
           1...cxd4 2.Kd2
           1...Kc1 2.Ke2
           1...c3 2.Kf2
           1...Rh8 2.0-0

(b) 1.Kg4! (>2.Bg5,Bf6,Be7,Bd8)
           1...e2 2.Bg5
           1...b5 2.Bf6
           1...Ra7 2.Be7
​           1...Ra8 2.Bd8