The question of sufficient mating force becomes more complex on larger boards. See the thread 12x12_checkmate for some interesting results obtained by H. G. Muller. In particular, both the Commoner (FW) and the Half-Duck (HFD) may fail to force mate against a lone King on a 16x16 board. A 12x12 board can be 'too large' for the Woody Rook (WD) or even the (WAD) piece.
The question of sufficient mating force becomes more complex on larger boards. See the thread 12x12_checkmate for some interesting results obtained by H. G. Muller. In particular, both the Commoner (FW) and the Half-Duck (HFD) may fail to force mate against a lone King on a 16x16 board. A 12x12 board can be 'too large' for the Woody Rook (WD) or even the (WAD) piece.