binding affinities have been more difficult to predict accurately compared to those for other host families. As discussed above, previous experimental work reported protonation state modulation of guests upon binding to CB8, thus we thought that this could play a role here for guests with multiple protonation states potentially accessible at pH 7.4. Indeed, when we modeled the guests in different protonation states compared to our initial predictions, the binding Δ estimate changed significantly and in some cases by more than 2 kcal/mol (Table ). In addition, for each of the guests (G1-G5, and G7 (see Table ), predicted binding free energies using one of the protonation states (neutral or protonated) were in agreement with experimental values, though the protonation state yielding best agreement varied by guest. These findings are in-line with previous literature results, and may warrant further attention from participants, since most participants did not account for possible protonation state changes for any guest other than G5.