Relative difference of the best-fit FD amplitude to the FD amplitude of the theoretical FD vs MSE for a mixture of different levels of data imperfection effects. In the left plot, no data refinement is included, whereas in the right plot data with extreme deviations from the identity line have been removed (for details, see the main text). The identity line (y = 100 * x) is marked as the solid black line in both figures, whereas the solid red line shows the linear regression line (linear regression equation and squared Pearson’s coefficient are given in red in both plots).