Detection probability of Mg II absorbers. Top: Detection fraction as a function of redshift for primary (hatched), and after incorporating the secondary (dashed) set. The average DECaLS r_mag of galaxies per redshift bin is shown as a square, along with the 16th and 84th percentiles. Bottom: Detection rate of Mg II absorber host galaxies with equivalent width (W₂₇₉₆) for primary sample with z < 1.6 (square). The cumulative fraction for all detections, including primary and secondary samples, is given by the right-hand-side ordinates.