Top: distribution of the kinematic asymmetry (k₅/k₁) with standard deviation (σ) errors calculated by the bootstrap method for BGGs in relaxed (red) and unrelaxed (blue) group in the left panel (a₁), and high/low gap and low/high offset groups in the top (a₂) and bottom (a₃) right panels, respectively. The fraction of nonregular (NR) rotators (k₅/k₁ > 0.08), quasi-regular (QR) (0.04 < k₅/k₁ < 0.08), and regular (R) rotating (k₅/k₁ ≤ 0.04) (dotted lines; van de Sande et al. 2017) are presented in Table 1 for the BGGs that reside in subsample groups. Representative stellar kinematic maps of BGGs defined as NR, QR, and R rotators are shown in the corresponding regions. Bottom: the fraction of regular BGGs as a function of stellar mass, separated by the subsample indicated in the legend (panels (b₁), (b₂), (b₃)). Dashed line shows the median trend for all BGGs in our sample. In each panel, the errors (color-shaded lines) are σ confidence intervals on the fractions calculated using the bootstrap method. In the histogram along the upper x-axis of the panel (b₁₁), we show the number of galaxies (N_gal) in each stellar mass data point for the relaxed and unrelaxed samples. Inset figure in the left panel (b₁₂) shows the median fraction of regular rotation BGGs as a function of stellar mass using the moving average method where the axes range is the same as in the main plot.