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In the domain of Fairy Chess the composer’s imagination has free rein, and
often the simplest change to the normal rules of chess leads to
interesting effects. Checkless Chess differs from orthodox chess in only
one respect. A check is only legal if it gives mate.
There is a big clue to the key in the diagram. Black is threatening to mate on the move by 1...Qe2, since 2.Bxe2 is illegal, being check but not mate. The key is 1.f5, making 1...Qe2 illegal, and threatening 2.Qd4, since Black can no longer reply 1...Bxd4. In the three leading variations the black queen attacks d4, so that it can capture after 2.Qd4 with mate, but in each case it interferes with a black piece, allowing a mate which works because a queen capture would give check.
One by-play variation 1...Qd5 2.Qf4 also exploits the checkless condition, while another 1...Rxd1 2.Sb6 is more orthodox.
Dafydd Johnston: This one was quite a surprise, and I must say I did enjoy it. Once I got my head round the implications of the checkless condition I found it impressive. Threatening mate by giving the white king a flight is strange enough, and the three 'interferences' by the black queen make a paradoxical theme.
Jacob Hoover: This was a real treat in that it had queen
self-interferences, a rare thing in chess problems.
Any comments or questions on this problem should be addressed to
Michael McDowell using the ‘Contact’ item in the menu on the left.