Our perturbation graph (Fig. ) has paths connecting all state pairs, with three intermediate states introduced along each path. These intermediate states are also modeled as 2-D harmonic oscillators, with force constants and equilibrium positions linearly interpolated between the end states. We sample n configurations from each state on every path, varying n from 10 to 5000. Using these configurations, we estimate free energy differences for all paths using three methods: BayesMBAR, cycle closure correction, and CBayesMBAR.