Average maximum likelihood value of r and the standard deviation as a function of the number of sub-bands in the case of unaccounted-for dust frequency de-correlation (model d6s1 with ℓ_corr = 10 and r = 0) compared to two cases of no de-correlation (model d1s1): r = 0 and r = 0.006. On top of the average r values and their standard deviation, we have overplotted the shape of the distribution as a “violin plot.” Note that for the d6 case the distribution is asymmetric for small n_sub, so that the average is not centered on the distribution.