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The selfblock is one of the simplest of chess problem themes, shown here in a fine task setting.
A brilliant key, 1.Se3, threatens 2.Sc4 and allows the black king to capture both rooks, with matching mates at either end of the diagonal - 1...Kxd6 2.b8Q and 1...Kxf4 2.Qh2. Black can selfblock three times on each flight square. 1...Rxd6 2.Rf5, 1...Sxd6 2.Sg4, 1...exd6 2.Rxe4, and 1...Rxf4 2.Re6, 1...Sxf4 2.Qd4, 1...gxf4 2.Rd5. There is one by-play variation 1...Sb2 2.Sg4.
Jacob Hoover: A lovely puzzle with a very pleasing self-block theme. I
found the by-play a little unimpressive, though.
I think Jacob is being a little hard on the composer. Three selfblocks on
each of two flight squares following a key which gives both flights is a
By-play is usually an afterthought, either arising naturally from the
matrix or added to force potential mating moves which are not used in the
main theme. I think that the composer would have been perfectly justified
if he had chosen to add a black pawn at b2 to eliminate the knight
defence, leaving his 8 thematic defences.
Any comments or questions on this problem should be addressed to
Michael McDowell using the ‘Contact’ item in the menu on the left.