06 May 2011

Caissa's Fairy Tales

Today, I'll take you on a short tour through a little book by Thomas Rayner Dawson called Caissa's Fairy Tales (published 1947). It's a loose collection of fairy chess problems embedded in fictional stories. Thereby, the reader becomes acquainted with certain types of fairy elements in an entertaining way. I chose three topics for you.

The first two diagrams are not really fairy problems. They simply add a constraint teasing the solver with a wordplay.

  1T. R. Dawson  
Caissa's Fairy Tales, 1947
  #3 with knight(5+4)  

  2T. R. Dawson  
L'Eco degli Scacci, 1918
  #3 with THE queen(8+8)  

In No. 1 it'd be easy to mate in three moves promoting one of the pawns to queen or rook. But it demands to mate with a knight. This should be accomplished using the one on c5, right? Let's see ...
1. d7! puts Black in zugzwang:
1. - Ne~ 2. Nc7+ Kb8 3. N5a6#
1. - Ne6 2. Nxe6 3. Nec7# So far, Nc5 mates as expected.
1. - Nxd7 2. Nxd7 3. Nc7# Oh, the Na6 also mates!
1. - Nf~ 2. dxe8=N 3. Nec7# Ha, mate can also be delivered by this knight!

Problem No. 2 suggests the queen c6 is to give mate. Hmmm ...
1. Qg6! c6,5 2. Ne6 ~ 3. Qxg5# Good, that works. But the black knight can spoil this idea.
1. - Nh6 2. Qxg5+ What's that? Don't we need that queen? Kxg5 3. d8=Q# As there is only one white queen in the set, it is still THE queen!
1. - N~ 2. Qxh5+ Kxh5 3. h8=Q# Again, THE queen.

The next two problems deal with the retraction of a move. Of course, only legal last moves can be retracted. And you have to choose the right retraction for White so that there is the possibility to mate in one.

  3T. R. Dawson  
De Standaard, 1925
White retracts and mates in 1 (2+15)
a) Diagram
b) Bf4 → f6
c) further Pb7 → f2

  4T. R. Dawson  
Eskilstuna Kuriren, 1933
Whatever Black retracts, White may retract and mate in 1 (12+10)

In No. 3 White could mate immediately with 1. Kg4#. However, the stipulation demands to retract a move, first.
a) Retract Kh4-h3 and play 1. Kg4#. Only the Bc8 is missing and it was captured at home. So, the white king did not capture on h3. Retraction of Kh2-h3 is not allowed, as the black pawn started on c7. Thus, the check on g3 would have been illegal.
b) Retract Kh2-h3 and play 1. Kgl# Analogous to a), Kh4-h3 is not allowed. Pawn g5 started on e7. On the other hand, the check on g3 is legal now, due to the possibility of f4xg3+.
c) Though Kh2-h3 could be retracted, it would be of no use. The white king could not leave the h-file. But the black bishop from c8 is now available for a capture. Retract Kg4xBh3 and play 1. Rxh3#.

Looking at No. 4, we quickly see that there is just a limited set of moves that Black can retract at all. It was the black pawn on f5 that made the last move. There are four possibilities and they remind of the Pickaninny theme (a problem in which a black pawn on its starting square makes each of its four possible moves).
  • Retract e6xRf5, Rf7-f5, then 1. Rc7#
  • Retract g6xRf5, Rg5-f5, then 1. Rxg3#
  • Retract f6-f5, Qgl-al, then 1. Qd4#
  • Retract f7-f5, Nc7-a6, then 1. Nd5#
Black cannot retract the capture of a bishop or a pawn on f5. In both cases, this would require too many captures by the white pawns. A capture of a knight or a queen is possible, though. The white pawn d2 could have promoted on d8 without a problem. In theses cases, the solution is not unique.

The last three problems feature a new type of fairy piece — the neutral men. Those can be moved by either side. Neutral pawns promote to neutral pieces on the first or on the eighth rank. The pieces are often shown by half white and half black symbols.
In 1912, Dawson invented the neutral pieces. Until his death in 1951, only 20 chess problems were composed using neutral men, 13 of them were by Dawson himself. Later on, these new pieces became highly popular.

  5T. R. Dawson  
Reading Observer, 1912

  6T. R. Dawson  
Fairy Chess Review 12/1940

  7T. R. Dawson  
Hampstead and Highgate Express, 1913

The key move of No. 5 is 1. Bd4! threatening 2. Bxc4# and 2. nNxd6# but not 2. nNb2#, as Black could defend with 2. - nNc4. The variations are as follows:
1. - N,dxe6 2. Bxc4#
1. - Rxd8 2. nNxd6#
1. - Kb5 2. nNxe5#
1. - exd4 2. Rxa5#

An Allumwandlung with a neutral pawn is shown in No. 6.
1. Nb1! (threat 2. Qxd3#)
1. - nPd1=nQ 2. nQxd3#
1. - nPd1=nR 2. Qxd3#
1. - nPd1=nB 2. Nd2#
1. - nPd1=nN 2. Nd4#
1. - Kxe2 2. Qd1#

No. 7 is a zugzwang problem:
1. Qh4! and now
1. - exd4 / nRh7,xh8 2. nRxf5#
1. - f4 2. nRxe5#
1. - Qxh8 / B~ 2. nRgxg6#
1. - Rxh6 2. nRxg7#

The key move creates a Q + nR battery. But, unlike a normal battery, it can only fire effectively when the neutral rook pins itself. Otherwise, Black would defend with 2. - nRg5.
In move 2, White considers the nRg5 to be white. Therefore, it can capture black pieces. It can also take neutral pieces, declaring them black for that purpose. As a further consequence, it controls certain squares like f5 in the second variation. Of course, after White has moved, Black could declare that neutral rook as black. But, looking again at the second variation, Kf5 is not a legal defense. White would again declare the nR as white. Dawson even says White must consider that he is giving check! This shows a general rule: a king may not put himself in check by a neutral piece.
The last two variations show that a neutral piece can be pinned by another.

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