The physical process of a ligand-protein interaction cannot be defined by a single number, even if it is a good quantifier of interaction. A protein-ligand complex has an overall zero-temperature total interaction energy, but there is also dynamics in usual conditions. The meaningful interpretation of a conformation binding energy has to include the likelihood of binding: physical binding from freely unbound and the process it takes to get there, and the comparison to other conformational binding modes all of which can be characterized by numbers of available binding states at thermal conditions. The physical geometrical-chemical interaction of the protein binding cavity is a constraint on available bound ligand states and thermal motion in the likelihood of being populated of a specific ligand. Both molecular dynamics simulations and docking calculations if performed in a distributional manner can access this.