Number of observed cycles versus phase deviation at the last cycle, comparing the RV and G-band curve models for the sample post-filtered down to filter-2 (see Table 1). More precisely, the top panel shows the phase deviation with respect to the last RV cycle and the number of RV cycles, while the same quantities are referred to the G-band time series in the bottom panel. In each panel, the thick red line marks the upper limit to the phase difference employed in post-filtering (Eq. (4)), while the dashed lines indicate n^cyc/r = 3, 2, and 1. Data points to the right of the thick red line are rejected. A similar picture emerges when the G_BP or G_RP time series are considered in place of G.