Redshift-richness distribution of all the MaDCoWS clusters (small grey dots). The red, filled circles display the clusters in our sample (i.e. with λ₁₅ > 40, see dashed line). The histograms on the top and on the right show their distribution in comparison with the full MaDCoWS sample. Dashed grey and red lines in the top-panel histogram show the median redshift of the two distributions (⟨z_all⟩∼1.06 and ⟨z_LoTSS⟩∼1.05, respectively).