Alphabetic Chess: The squares are considered in the order a1, a2…a8, b1…b8, c1 and so on to h8. At each turn, only the unit standing on the square which comes earliest in this order may move. However check and mate are normal.
Nightrider(N): Operates along straight lines with squares lying a Knight’s move away from each other.
No.1221Chris Feather England original – 28.05.2017
Because of ABC, the white King must be checked in order to move. Obviously the two final positions are identical, however no moves are repeated, as the full notation shows: the king and nightrider routes are different and even at moves 6 and 7 only the arrival squares are the same. (Author)
