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This week’s problem was the original example of the le Grand theme. More
details on Friday!
Solution to be published on Friday 22nd August.
The le Grand theme involves a reciprocal change between the threat and the mate to
the same defence, across two phases of play. Thus, in this example, the try 1.Qe4?
threatens 2.Rc4#. The thematic defence is a random move of the bS, eg. 1...Sf6,
which is met by 2.Rc6#. There are also the by-play variations 1...Sb4 2.cxb4# and
1...Qxe4 2.Sxe4#, but 1...Se7! refutes.
After the key 1.Qe6 threatening 2.Rc6#, a random move by the bS eg.
1...Sf6 is met by 2.Rc4#. In other words, the threat in the
try-phase (2.Rc4) becomes the mate in the post-key phase, whilst the mate in the
try-phase (ie. 2.Rc6) becomes the threat in the post-key phase – the
characteristic of the le Grand theme. We also have the by-play variations
1...Se3 2.Sxd3#; 1...Sxb6 2.Bxb6#; and 1...Bxe6 2.Sxe6#.
Any comments or questions on this problem should be addressed to
Steve Giddins, our Librarian and Archivist, using the 'Contact'
item in the menu on the left.