e/Regret (decision theory)

Information
has gloss	eng: Regret (often also called opportunity loss) is defined as the difference between the actual payoff and the payoff that would have been obtained if a different course of action had been chosen. This is also called difference regret. Furthermore, the ratio regret is the ratio between the actual payoff and the best one.
lexicalization	eng: regret
instance of	c/Optimal decisions