In the left panel, the spin parameter proxy within the effective radius ellipse, λ_Re, including measurement errors, is plotted as a function of galaxy ellipticity measured at the effective radius for BGGs in relaxed and unrelaxed groups. The various curves/lines separate galaxies into slow and fast rotators following the two separate schemes proposed in Emsellem et al. (2011, EE+11) and Cappellari (2016, MC+16). In the right panel, the fraction of slow and fast rotators is compared using horizontal bars with binomial errors for relaxed and unrelaxed groups. Representative examples of stellar kinematic maps are shown inside the figure for the fast (top) and slow (bottom) rotator BGGs.