Mean absolute deviations (kcal/mol) for all assessed methods, listed in alphabetical order within the rungs of Jacob's Ladder, as well as mean MADs for each rung of Jacob's Ladder. Results are for the def2-QZVPP basis set, except for the -3c methods which use their own modified basis sets. The lowest MAD in each rung is bolded. Given that this benchmark set is inspired by our mostly organic enzyme benchmark set and the organometallic benchmark sets MOR41, 50 MOBH35 51 and ROST61, we briefly compare our top-performing functionals to those. Amongst the GGAs, OLYP-D3(BJ) has the lowest MAD, which was also the case for the organic enzymes. revPBE-D3(BJ) has the second lowest MAD, while its D4 variant was consistently among the top performing GGAs for the three organometallic benchmark sets. MN15-L-D3(0) is the best thirdrung (meta-GGA/NGA) functional based on MAD, as it was for MOBH35; it is followed by B97M-D4 and B97M-V. Those functionals and the related hybrids ωB97M-V and ωB97X-V, which are some of the best hybrids in this study, are consistently good performers in the previously mentioned studies as well as many other benchmark sets for main group and tran-sition metal chemistry. ωB97M-V shares first place amongst the hybrids with MPW1B95-D3(BJ), which was the second best hybrid on MOR41. Finally, the best double hybrid (and overall best DFA) is SOS0-PBE0-2-D3(BJ), which was also the best for the organic enzymes. ωB2GP-PLYP-D4 and ωB2PLYP-D4 are second and third, which is interesting as they were originally developed for excited state time-dependent DFT, but ωB2PLYP has already been shown to perform well in predictions of UV-Vis spectra for copper complexes. 185 None of these top three double hybrids were tested on the aforementioned organometallic benchmark sets so we also mention the fourth and fifth best functionals, revDOD-PBEP86-D4 and PWPB95-D3(BJ); the former was recommended by the MOBH35 study, while the latter was the best DFA for both ROST61 and MOR41. Taking a closer look at the hybrids and double hybrids, we present violin plots of the best variant of selected functionals in fig. , with each point colored by reaction; equivalent plots for the GGA and meta-GGA functionals are also given in figure in the SI. The majority of deviations lie between -10 and 5 kcal/mol for the hybrids, and -5 and 5 kcal/mol for the double hybrids. revDOD-PBEP86-D4 and revDSD-PBEP86-D4 have the tightest distributions, with interquartile ranges (range containing the middle 50% of data points) of only 1.5 and 1.6 kcal/mol, respectively. For the double hybrids, the trend in error ranges (distance between the maximum and minimum deviations, i.e. the height of each plot in fig. ) roughly matches the functional ranking by MADs, with SOS0-PBE0-2-D3(BJ) and ωB2GP-PLYP-D4 being first and second again on this statis-tic. This is not always the case for the hybrid DFAs, as the error ranges are strongly influenced by the functional's performance for CDO 3RE4 and 5RE1, which generally have large positive deviations that lie significantly higher than the others. While the absolute deviations for these steps are particularly large, neither stands out on an equivalent plot of percent deviations (PDs) (fig. in the SI) as their reference values are some of the largest by magnitude in the set. CDO 3RE4 has a reference RE of -77.322 kcal/mol, however, so its average percent deviation (PD) across all hybrid functionals is only 29.5%; for 5RE1, these values are -43.307 kcal/mol and 37.8%, respectively.