r-Magnitude dependence of KiDS DR4 photo-z statistics based on the findings of Wright et al. (2018) for the deep spec-z fields (blue lines) and a direct comparison of DR4 photo-z and SDSS/2dFLenS spec-z (red lines). Top panel: normalised-median-absolute-deviation of the quantity Δ_z/(1 + z), middle panel: mean μ_Δz of that quantity, and lower panel: rate ζ_0.15 of outliers with |Δ_z/(1 + z)| ≥ 0.15. (Note that this definition of ζ_0.15 exaggerates the outlier fraction when σ_m approaches 0.1.) The scatter between neighbouring points gives an indication of the error bars on these quantities.