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Certain readers have suggested that last week's problem was a little too easy, so this
week, I am hitting back with a more heavyweight effort! However, it is a superb problem,
which amply repays a serious solving effort.
This is an example of Plachutta Interference. White sacrifices on the interference
square of two like-moving Black pieces (eg. queen and bishop, or, in this case, queen
and rook). Whichever black piece captures, becomes overloaded, and this overload is then
exploited for a mate.
White kicks off with 1.Sa2 This threatens the Plachutta 2.c4+. For example,
assuming for the moment that Black passes, 2.c4+. Now after 2...Qxc4, the queen
overload is exploited by 3.Sc3+ Qxc3 4.Be4#, whilst after 2...Rxc4 the overloaded rook
is decoyed away with 3.Sb4+ Rxb4 4.Qc6#
So, how does Black defend? He can do so by playing either Q or R to the other side of
the c4-square (an anti-critical move), so as to prevent the interference working
after 2.c4. For example, 1...Qa4 However, now White strikes with a different Plachutta
sacrifice on the same square: 2.Qc4+! with the variations 2...Qxc4 3.Sc3+ Qxc3
4.Be4# and 2...Rxc4 3.Be4+ Rxe4 4.Sc3#.
The other black anti-critical defence is 1...Rxc2 but this is met by yet another
different Plachutta sacrifice: 2.Bc4+! and then either 2...Qxc4 3.Qc6+ Qxc6
4.Sb4#, or 2...Rxc4 3.Sb4+ Rxb4 4.Qc6#.
A beautiful problem by one of the finest composers of the last 40 years.
Any comments or questions on this problem should be addressed to
Steve Giddins (our Libarian and Archivist) using the 'Contact'
item in the menu on the left.