(A) Strength σ_y of GCCs with different grain diameters D and GB thicknesses l fitted with . (B) Replots of (A) by the fraction of GB area A_GB/A_tot. The horizontal dotted lines in (A) and (B) represent the strength of the completely disordered glass. (C)–(E) The fitting parameters from (A). (C) a₁=0.35 log(D)-1.76. (D) a₂=0.08D+1.34. (E) a₃=0.204D. (F) The contour map of σ_y(D, l) in (A). The ridge is fitted by l^*=0.21 (D^*-50)^0.62+1 (dashed curve).