Evolution of f_blue for individual (top panels) and stacked (bottom panels) clusters as a function of cluster-centric distance (r/r₂₀₀) for different bins of redshift (increasing rightward) for a mass-selected sample with a mass corresponding to the original M_V in Butcher & Oemler (1984). Symbols are as in Figs. 10 and 11. We add a new panel at z = 1.05 for model prediction, where we overplot the measured values of f_blue for the RzCS 052 cluster in Andreon et al. (2008).