The well-established functionals B3LYP+D3 and ωB97M-V afford MAEs of 2.5 kcal/mol and 1.5 kcal/mol respectively. The "average maximum errors" that are reported in Fig. represent averages of the maximum errors for each of the barrier height data sets that are considered in Fig. ; these values are 6.0 kcal/mol for B3LYP+D3 and 4.0 kcal/mol for ωB97M-V. Together, the errors for these two functionals set a baseline for what constitutes good performance. For B(20)LYP, which uses the same fraction of exact exchange as in B3LYP, the MAE is 2.3 kcal/mol and the average maximum error is 6.0 kcal/mol. These statistics are quite similar to those for B3LYP+D3, whereas the B(30)LYP functional performs slightly better with a MAE of 1.8 kcal/mol. The BLYP+D3 functional is not expected to perform well for problems where SIE is important and is included here simply to set a boundary representing poor performance.