Multiple Solutions

In general two-movers with multiple solutions are not considered to be sound problems.  However, sometimes multiple solution problems can be composed intentionally with wonderful effects.  Here are some of my favorites.

Macleod, Norman
Die Schwalbe 1962 v. in The Problemist

#2

2 solutions

11 + 9

​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). 

1.Sc1! (>2.e4)
     1...Kd5 2.Bc3
     1...Qxd4 2.e3

1.e3! (>2.Sf4)
     1...Kd5 2.Sxb4
     1...Qxd4 2.Sc1

Barnes, Barry
The British Chess Magazine 1970

#2

2 solutions

8 + 4

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.  

1.Qxc5 (-)
   1...Kxe6 2.Qc6
   1...c3 2.Qf2
1.Qxc4 (-)
   1...Kxe5 2.Qd4
   1...cxb4 2.Qf1

Shire, David
The Problemist 1987

#2

2 solutions

9 + 8

Here we have a polished example of the Odessa theme between the two solutions.  The mechanism uses self blocks to create the reversals

1.g3! (2.Qc2/Sd2)
   1...Qxf5 2.Ra4
   1...exf5 2.Sc5
1.g4! (2.Ra4/Sc5)
   1....Bxf4 2.Qc2
   1...Sxf4 2.Sd2

Holladay, Edgar
The Problemist 1974

#2

4 solutions

8 + 6

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.  

1.Sf7! (>2.Sxh6/Sxe5)
   1...Kxh5 2.Sxe5
   1...Kf5 2.Sxh6
1.Kf7 (-)
   1...Kxh5 2.Qh3
   1...Kf5 2.g4
1.Bf7 (-)
   1...Kf5 2.Bxe6
1.Rf7 (-)
   1...Kxh6 2.Rf4

Sydenham, Colin
The Problemist 1987

#2

3 solutions

8 + 4

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.Bg3! (-)
   1...Kd5 2.Qf7    (A mates, B pins)
   1...Sd~ 2.Rbb3
   1...Sxb5 2.Qxe4
   1...Se~ 2.Rc3

1.Bf6! (-)
   1...Kd5 2.Rxd4   (B mates, C pins)

1.Be7 (-) 
   1...Kd5 2.Rxc5   (C mates, A pins)

Rice, John
Pravda 1968

#2

3 solutions

13 + 6

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.  

1.Sf4+! 
   1...Ke5 2.Re1
   1...Ke4 2.Re8
   1...Kc6 2.Rf6
   1...Kc4 2.cxd3
1.Sf6+
   1...Ke5 2.Re8
   1...Ke6 2.Re1
   1...Kc6 2.Bb7
   1...Kc4 2.Rf4
1.c4+
   1...Ke4/Ke5 2.Re1
   1...Ke6 2.Re8
   1...Kc6 2.axb5
   1...Kc4 2.Qxd4

Moen, Kabe
Original

#2

3 solutions

6 + 4

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.

Set:
1...Qd4+/Qd3/Qd2 2.RxQ
1...Qxd1 1.Rxd1
1...f5 2.Bxe5

1.Bh2 (-) pure waiting move
1.Bf4 (-) added mate after 1...exf4
1.Rh1 (-) change after 1...f5 2.Rh6