Expected deviation of the X-ray-flux-based mass estimate from the true (input) mass. Triangles show the ratio of the mass predicted by eq. (1) to the true M_500c value for clusters that follow adopted scaling relations from Vikhlinin et al. (2009). Solid circles show the same ratio when the factor z^0.5 (as in eq. 2) is accounted for. Different colors indicate the mass range of clusters that are expected to be present above a given redshift.