Left panel: distribution of the number of cells in the initial grid and its effect on the Bayesian block algorithm (see Sect. 3.8). The dashed line is an upper limit to the number of blocks that can never exceed the number of initial cells. A bug in the code, described in Sect. 3.16, prevents us from reaching this line. The distribution in the left panel clearly shows that this bug has no effect on light curves that start from a grid with > 10 cells. Right panel: cumulative distribution of the number of initial cells. We show the 0.9 and 0.99 values with solid lines. Currently, about 77% of the sources are not characterised by Bayesian blocks because their initial grid has fewer than three cells.