In SAMPL7, experimental characterization of bound conformations via NOESY NMR, and some computational approaches, showed that polar head groups of guests can occupy either the primary (primary alcohol opening) or secondary face (secondary alcohol opening) of bCD and functionalized derivatives, and in some cases both orientations were populated. For SAMPL9, we thought most methods (if not all) needed to account for primary and secondary binding modes of phenothiazines individually, and due to asymmetry of both guest and host this may require additional binding modes in each face. For the different binding modes we use the notation defined previously , so the binding modes are referred to here as SS (secondarysecondary), PP (primary-primary), PS (primary-secondary), and SP (secondary-primary), where the first word represents the ori-entation of guest's R1 amine group and the second word denotes the orientation of the R2 functionalization on the phenothiazine core (see Figure ). Even with some methods that deploy enhanced sampling techniques, these binding modes may never interconvert in simulations and thus simulations would give inaccurate binding free energies, thus requiring modeling each different metastable binding mode individually. For initial reference calculations, only one pose for each orientation (primary and secondary) was included (see Figure ), and will include additional orientations considered in retrospective studies. Moreover, other participants noted considering additional orientations post challenge.