private bool HasLegalMovementModifiers(Move move)
{
if (Math.Abs(move.RowChange) == Math.Abs(move.ColumnChange)) //diagonal
return true;
if (move.RowChange != 0 && move.ColumnChange == 0) //vertical
return true;
if (move.RowChange == 0 && move.ColumnChange != 0) //horizontal
return true;
return false;
}