Nils G.G. van Dijk
Stella Polaris, 1966
Mate in 2
Nightriders f2, h4
In response to a request, a problem which features a grasshopper and nightriders. Remember that the grasshopper moves on queen lines but must jump over a hurdle to the square immediately beyond, while the nightrider moves in knight moves along a line. For problems using these pieces, see the first two examples here.
1.Nd2 threat 2.N×f6. 1...Re4 (interference with N and B) 2.Be7; 1...Ne4 (interference with B and R) 2.Bd6; 1...Be4 (interference with R and N) 2.Gc8; 1...Nb4 2.G×g4; 1...Re6 2.Bf7. The white battery is controlled by the three black pieces attacking a8, c8 and e8. The defences at e4 show a triple Grimshaw, with each piece interfering with the other two. Two of the mates are shut-offs of the interfering piece. The grasshopper mates twice, and guards the mating bishop after 1…Re6 provides a hurdle.
Richard Stein: A superb triple-interference effect on e4 where each piece cuts off the other two.