A problem on this piece: On 3x3 board, Ubi-Ubi can never move to center if it is not at center, and it totally can't move if it is at center.
This 'problem' is not unique to the Ubi-Ubi; and ordinary Knight has it too. In fact every leaper has it, the longer the leap, the earlier it sets in when you shrink the board. A Camel would be useless in the center of a 5x5 board, and cannot reach it when staring elsewhere. A Flamingo ((6,1) leaper) would have no moves in the central 4x4 area of an 8x8 board.
This 'problem' is not unique to the Ubi-Ubi; and ordinary Knight has it too. In fact every leaper has it, the longer the leap, the earlier it sets in when you shrink the board. A Camel would be useless in the center of a 5x5 board, and cannot reach it when staring elsewhere. A Flamingo ((6,1) leaper) would have no moves in the central 4x4 area of an 8x8 board.