double rate(Board board)
    {
        int sumHeight = 0;
        
        //count the holes and sum up the height
        for(int x=0; x <board.getWidth(); x++)
        {
            final int colHeight = board.getColumnHeight(x);
            sumHeight += colHeight;
        }
        
        double avgHeight = ((double)sumHeight)/board.getWidth();
        
        //first variance
        int varisum = 0;
        for(int x = 0; x < board.getWidth(); x++)
        {
            final int colHeight = board.getColumnHeight(x);
            varisum += Math.pow(colHeight - avgHeight, 2);
        }
        
        return varisum / board.getWidth();
        
    }