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Torsten Linss, Mark Ridley, BDS & Paul Valois

The Problemist, 1994

#2
Sentinels
LEO a5
PAOs a4, c4

1.Qc2!          (2.Qd3[+wPc2]#)

1...PAc5[+bPc4]  2.LEb6[+wPa5]#
1...PAf4[+bPc4]  2.LEg5[+wPa5]#
1...PAe4[+bPc4]  2.LEe5[+wPa5]#
1...PAd4[+bPc4]  2.LEc5[+wPa5]#
1...PAc3[+bPc4]  2.Qd2[+wPc2]#
1...PAcb4[+bPc4] 2.Qd2[+wPc2]#

In 1994 the German composer Torsten Linss was studying in Newcastle. Of course, composers like to meet up and such an opportunity couldn’t be ignored, so a group of composers in the North of England made the appropriate arrangements. This problem was one result of that meeting.

At that time I had just begun to understand the possibilities of mixing Sentinels with Chinese Pieces and suggested an idea to the group. In making the key, they queen goes to c2 so that White can threaten mate on d3 with his queen guarded from the sentinel pawn left behind on c2. Any move of the black Pao c4 will leave behind a black pawn on c4, which will thus defend against the threat. All Black’s defences are by that Pao. The first four allow the white Leo to check the black king over the Pao. Each of those checks is actually mate because the Pao can’t relieve the check by moving away – if it were to do so it would leave behind a black pawn, over which the white Leo would still check the black queen. In the last two variations the black Leo lands on a square between the white Leo and d2, thus guarding d2 and allowing Qd2#.