Normalized velocities of red and blue galaxies (solid red circles and blue open triangles) vs. m − m₃, where m₃ is the magnitude of the third brightest galaxy in each cluster. Data are binned in intervals of 0.5 mag. The error bars are obtained by a bootstrap resampling procedure. Points without error bars indicate the values based on only three galaxies. The dashed line represents our fit for red galaxies in the m − m₃ ≤ 0.5 region. The results of Biviano et al. (1992) are shown for comparison (small black squares).