Similar to previous iterations of SAMPL, judging by the performance of submissions the CB8 systems posed a bigger challenge for participants. Five CB8 systems (CB8-G4, CB8-G7, CB8-G3, CB8-G6, and CB8-G1) all had an RMSE greater than 4 kcal/mol (Figures and), compared to two in GDCC (TEMOA-G4 and TEETOA-G4). CB8 guests contained more complex fused ring systems at their nitrogen centers, and had additional protonation states that perhaps needed to be considered, likely complicating predictions.