This site now hosts a complete archive of PDF versions of The Problemist Supplement, from 1992 to the current year. This magazine is aimed mainly at newcomers to chess composition, so it is recommended for those who want to find out more about chess problems. You can find the archive here.
The problems set in the recently completed Postal Round of the 2014-2015 Winton
Capital British Chess Solving Championship included a ‘mate in 3’ by Edward Winter-Wood
that elicited praise from several solvers. That problem won First Prize in the 1888
tourney of the Sheffield Independent. This week’s problem is the composition that
came second in that competition. It is by Percival Fothergill, a prolific composer of
that time, who was known to solvers of the day by his memorable initials – PGLF –
which appeared above all his published problems.
Michael McDowell mentioned recently that one way to solve ‘mate in 2’
problems is to find a key that provides mates for those black moves in the diagram
position that could not be followed by immediate mate. The same technique can be
applied to ‘mates in 3’, though in their case, the provision will be
of mates in at most two moves rather than immediate mate only. Look for strong black moves
in the diagram position – checks, king-flights, moves that give
the black king a flight, captures etc – that are not provided with mating continuations, and find
a key that provides for them. That is certainly a big enough hint in this case!
This old-fashioned problem features a queen sacrifice and two model mates. Model mates
are those where each square around the black king is guarded only once and all the white
pieces on the board (with the exception of the king and pawns) play a part.
The key is 1.Ba3 which threatens 2.Qb5+ Kxe4,Ke6 3.Qf5#. The star variation is 1...Kxc4
2.Qb5+ Kxb5 3.Sd6# including the aforesaid queen sacrifice and the first model mate. The second
model mate comes after the other black king flight 1...Kxe4 2.Qe2+ Kd5 3.Sb6#. If Black
plays 2...Kf4 in this line then White mates by 3.Bc1# – not a model. Other variations
are 1...Ke6 2.Qb6+ Kd5/Kd7/Kf7 3.Qc6/Sf6/Qg6# and 1...d3 2.Qe5+ Kxc4 3.Sd2#