The CG models consistently underestimate the forces across all models (Figure ) and the underestimation monotonically increases with decreasing resolution (Figure ). This is consistent with the loss of degrees of freedom in CG models and the increase of frictional forces dominating the deterministic component of the force per bead. The prediction of errors are slightly better for the ML and TL models than the SP models, as was expected based on the earlier analysis of the mean force errors (Fig. and). This comparison is shown for the R2 model in Figure but reflects the general behavior. The differences in the models become less apparent for coarser mappings as the force underestimation increases. The minimal error reduction by the NN models suggests that the force errors are irreducible and more properly described by stochastic friction forces rather than deterministically by the CG potential.