 In social choice theory, Bayesian regret is the average difference in social utility between the chosen candidate and the best candidate.It is only measurable if it is possible to know the voters' true numerical utility for each candidate – that is, in Monte Carlo simulations of virtual elections.If Bayesian regret can be "measured only if it is possible to know the voters' true numerical utility for each candidate", it would seem to be irrelevant to two voting methods that instead grade the utility of each candidate