Mean difference between our “red-sequence” redshifts and the spectroscopic redshifts from SDSS (top). Scatter between the redshifts after accounting for the bias (bottom). Open symbols indicate the scatter for all matches, solid ones are obtained after removing the outliers (| z_RCS2−z_SDSS | > 0.15). The dashed/dotted-dashed line shows the mean scatter including/excluding outliers. We correct the mean redshift bias in our analysis.