Is an Arabian mate possible without the king’s help? Can an Arabian mate be enforced without the king's help in this position?
[FEN &quot;r6k/8/8/8/8/8/8/K6n w - - 0 1&quot;]
I don't think it is possible to forcibly mate the king with rook and knight only.



Proof: The only mating position is with the white king in a corner, the rook giving check from an adjacent square and the knight protecting the rook and covering the escape square.

For simplicity let's say Ka1, Rb1, Nc3. There are 7 other equivalent positions to this one.

If you retro-analyze the position the last move must have been with the rook along the b file from somewhere between b3 and b8. For the following analysis it does not matter from where it came.

Then what was white's last move? It certainly was a king move from a2, b2 or b1 to the corner (a1). However, since white was not forced to move the king to the corner but could have moved to a3 or c1 (or to b3 if the rook was standing there), the mate cannot be forced.

[fen "1r6k/8/8/8/8/K7/4n3/8 w - - 0 1"]
[StartPly "4"]

1. Ka2 Nc3+ 2. Ka1?? (2. Ka3!) Rb1++