Top: distribution of the free-knot spline fit residuals for model parameter η = 45 days, η_ml = 300 days in the ECAM light curves of SDSS J1226−0006. The orange and blue histograms represent the distributions of data residuals whereas the grey histogram corresponds to the distribution of the residuals for the 800 synthetic light curves created using the generative model. Middle panels: normalised number of runs z_r for the synthetic curves (grey histogram) and for the data (orange and blue vertical lines). Bottom panels: residuals for the free-knot spline fit to the data, shown in blue and orange for images A and B, respectively. One example of the typical residuals obtained on applying the free-knot spline curve shifting technique on a simulated light curve is shown in black. Residuals are statistically similar to the observed data in terms of dispersion of the residuals, σ, and normalised number of runs, z_r (Eq. (2)).