Showing by means of simulation that spread in PA is only minimized when bursts have a non-varying RM and PA. We simulated 15 bursts with same RM and same PA (top left), same RM but different PA (top right), different RM but same PA (bottom left), and different RM and different PA (bottom right). In each of the cases, we corrected for one RM and measured the spread in PA after correction, which is plotted with blue dots in each of the subplots. The spread in PA is greatly minimized and appears similar to a parabola only in the case of same RM and same PA.