SF efficiency (SFE) as a function of the boundedness of the regions (parameter b_regions) across the merger sequence. From left to right and top to bottom, the merger stages are isolated galaxies (blue), galaxy pairs (red), early-stage mergers (orange), mid-stage mergers (magenta), and late-stage mergers (black). The Spearman’s rank correlation coefficients (ρ_s) and the power-law indices (N) of the best-fit relations are indicated. The bottom right panel shows the mean values of log₁₀SFE_regions and log₁₀b_regions; the error bars represent the mean absolute deviation for each merger stage.