## Tuesday, June 24, 2008

### Nightrider

The Nightrider, (German Nachtreiter, French Noctambule), is a fairy piece, which has been invented in 1925 by the British founder of the fairy chess T. R. Dawson.

The Nightrider moves in a straight line with one or more Knight-steps. It is a (1,2)Rider and it is symbolized in chess diagrams with an upside-down Knight 'looking' to the right and in texts with the letter N.
Since the Nightrider is a linear piece, we can observe mutual interferences between Nightriders and other linear pieces.
If there is an opponent piece on the arrival square, the Nightrider captures it. All the intermediate steps must be on free squares. If the Nightrider stands on a8, it can move to b6, c4, d2, c7, e6, g5. If we put on b6 a piece, if it is friendly piece the nightrider can not move to b6, if it is opponent piece it can be captured, and in both cases the nightrider cannot move to c4 και d2.

If there are Nightriders in the initial problem position, then a pawn can be promoted to Nightrider.

The Knight, depending on where it stands on the chessboard can threaten 2, 3, 4, 6, 8 squares. The Nightrider, on the other hand, can threaten 6, 7, 8, 9, 10, 11, 12 squares.

 (Problem 107) T. R. Dawson, British Chess Magazine, 1925 Mate in 5, (Nightrider on c6) #5 (3+1) (1+0 nightrider) [8/2K5/k1Ν5/8/8/2S5/8/8]

The King together with two Knights cannot win a King (K + S + S vs K), but the King together with a Knight and a Nightrider (K + S + N vs K) can win a King! (Because the Knight cannot win a tempo, but the Nightrider can!).

Tries: {1.Kc8? / Kb8? Kb6!}, {1.Ne2? / Ng4? / Ne5? Ka5!}, {1.Ng8? Ka7!}, {1.Sc3~? K(x)b5!}.
Key 1.Ne7! Ka7
2.Ng3 Ka8 3.Ne4 Ka7 4.Sb5+ Ka8 5.Nd2#

 (Problem 154) T. R. Dawson, Problemist, 01/1927 Mate in 2, (Nightrider on e5) #2 (6+7) (1+0 nightrider) [2s5/8/pP2p3/2KbN3/2pP4/2S5/2s5/k2S4]

In orthodox problems the royal battery has at most 6 thematic variations (task).
In problem-154 Dawson shows the royal battery, with a King and a Nightrider, to have 8 thematic variations! (Fairy task)!

Key 1.Nd7! (zz zugzwang).
1...Sc8~ 2.Kd6#
1...e5 2.Kxd5#
1...Sxd4 2.Kxd4#
1...Bd5~ 2.Kxc4#
1...Sc2~ / Sb4 2.K(x)b4 #
1...a5 2.Kb5#
1...Sxb6 2.Kxb6#
1...Bc6 2.Kxc6#

(This post in Greek language).