Comparison of BGG selection methods. Left: Violin plots of stellar mass distributions for BGGs selected using mass-based, luminosity-based, and hybrid criteria. Center: Cumulative distribution functions (CDFs) of the absolute differences in stellar mass (Δlog₁₀(M_⋆)) and R-band magnitude (ΔM_R) between mass- and mag-selected BGGs, showing that ∼65.7% of the sample has Δlog₁₀(M_⋆) < 0.3 dex, while ∼5.7% exceeds 1 dex. Right: Agreement rates between selection methods. The hybrid BGG matches the mass-based and mag-based selections in 77.1% and 71.6% of groups, respectively, while the mass and mag selections agree in only 48.7% of cases.