Evaluated on the recent PDB dataset (Methods), which is restricted to structures with a reported resolution of <2.5 Å (n = 5,983 chains) and residues with a B-factor of <30 Å2 (n = 609,623 residues). Residues are binned by pLDDT, with bin width 5 between 20 and 70 pLDDT and bin width 2 above 70 pLDDT. A χ1 angle is considered correct if it is within 40° of its value in the PDB structure75. Markers show the proportion of correct χ1 angles within each bin; error bars indicate the 95% confidence interval (two-sided Student’s t-test). The smallest sample size for the error bars is 193 residues for the left-most bin.