As a result, we conclude that the SASA of the scissile bonds is a weak predictor for proteolytic stability. GF 13 and GF 10, which were experimentally found to be more proteolytically stable than the wild type, did have a lower SASA value than the wild type at both sites. Notably, as the most proteolytically stable structure, GF 13 also had the lowest SASA values at both sites. However, GF 10 had the second-longest 𝛼-chymotrypsin half-life, but not the second-lowest SASA values at both sites. At the scissile bond between B26 and B27, most glycoforms had a lower SASA value than that of the wild type, but some of them were experimentally identified as less proteolytically stable than the wild type. Overall, the SASA values of either scissile bond have roughly the same efficacy given similar values of Kendall's tau correlation coefficients. However, if we are only interested in the comparison between the wild type and any glycoform instead of between any two of the glycoforms, the SASA value of the scissile bond between B25 and B26 is marginally more indicative than the SASA value of the other site. Specifically, among all the glycoforms that had shorter 𝛼-chymotrypsin half-lives than the wild type, GF 3, GF 4, GF 7, and GF 8 indeed had higher SASA values at this site than the wildtype. As for GF 6 and GF 11, which also had short 𝛼-chymotrypsin half-lives than the wild type, the SASA value at the B25-B26 scissile bond failed to classify them as the less proteolytically stable variants. Notably, the errors in the metric are generally large, which might be attributable to the fact that the SASA of the scissile bond was calculated from only 4 atoms (CONH atoms) and could lead to larger fluctuations in nature. Regardless of whether these large error bars are a direct result of the dependence of the initial bias or not, this high uncertainty undermined the predictiveness of this metric, making it less useful. In the lower panel of Figure , the SASA of residue B25 is less predictive than the SASA of the other site. Although an agreement with experimental results can be seen from GF 13, which had the lowest SASA at residue B25 and was previously found to be the most proteolytically stable, other glycoforms, regardless of the 𝛼-chymotrypsin half-life, all had a lower value compared to the wild type. The Kendall's tau correlation coefficient, which was close to 0, shows that the SASA of residue B25 was almost uncorrelated with the 𝛼-chymotrypsin half-life.