public override bool IsValidMove(Move move, ChessGame game)
{
ChessUtilities.ThrowIfNull(move, "move");
ChessUtilities.ThrowIfNull(game, "game");
Position origin = move.OriginalPosition;
Position destination = move.NewPosition;
PositionDistance posDelta = new PositionDistance(origin, destination);
if ((posDelta.DistanceX != 2 || posDelta.DistanceY != 1) && (posDelta.DistanceX != 1 || posDelta.DistanceY != 2))
return false;
return true;
}