This problem originally had a bB on h7 to thwart the try 1.e3? but was later removed and now has two solutions. We have wonderful play in both solutions including Schiffman defenses, pin mates, battery play, and a true Salazar theme (reversal of key move and variation).
This is probably my favorite double solution problem. I love line doubling and this is a wonderful example with two flight giving keys and perfectly match play in each solution.
Here we have a polished example of the Odessa theme between the two solutions. The mechanism uses self blocks to create the reversals
In this problem Black does not have any moves so White must give the bK some room to move. A different piece plays to the f7 square to release the stalemate.
Problems with multiple solutions make for a nice platform for cyclic play and here we have a beauty. In this problem the wRs and wQ take turns pinning for each other and mating. Set wQ=A, wRd3=B, and wRb5=C
1...Kd5 2.Qf7 (A mates, B pins)
1...Kd5 2.Rxd4 (B mates, C pins)
1...Kd5 2.Rxc5 (C mates, A pins)
Here is something exotic from the British grandmaster. Notice that the bK has many flights, five to be exact: e4,e5,e6,c4,c6. Here the three solutions all have checking keys but there is beautiful mate transference on the e-file flights and changed mates on the c-file flights. A wonderful problem which goes beyond the usual problem conventions.
Finally here is one of my own. You may recognize it as a modification of one of my old problems. It is nothing special but it does have some interesting features. First, it is a complete block - every move by Black has a set reply. For complete blocks, there are 3 three types of non-threat caring solutions: a pure waiting solution, a solution with added mates, and a mutate. Each of the solutions accomplishes one of these.
1.Bh2 (-) pure waiting move
1.Bf4 (-) added mate after 1...exf4
1.Rh1 (-) change after 1...f5 2.Rh6