Chess Problem with Fairy Piece

the Nightrider

Fairy chess problem composers offen make use of `fairy pieces': pieces different from those that appear in a normal game of chess. One of such fairy pieces - and one which has been used very often - is the Nightrider, a piece that can make more knight-moves in the same directions in one turn.

The Nightrider moves as follows: it moves as a knight, but can continue to move in the same direction with additional knight moves, provided that the `leaping points' are all empty. For instance, in the diagram below, the nightrider on e5 can move to c1 (as d3 is empty), but it cannot move to a4.

The problem below was composed by T. R. Dawson; published first in the Problemist in 1927, and appears in Dawsons book Caissa's Wild Roses, which appeared in Five Classics of Fairy Chess. The nightrider is displayed as an upside-down knight.

White:
King c5; Nightrider e5; Knight c3, d1; Pawn b6, d4.

Black:
King a1; Knight c2, c8; Bishop d5; Pawn a6, c4, e6.

Mate in two moves.

(Mate in two moves means: find a move for white such that he can mate black after every move of black.)

Solution