A payoff distribution describes the probabilities of rewards produced by a particular action, such as pulling one slot machine. Its mean and standard deviation summarize typical payoff and variation. section 12.1.6
Three slot machines
A noncontextual multi-armed bandit offers three machines with payoff parameters (mean, standard deviation) of (8, 0.5), (10, 0.7), and (5, 0.45). Each pull samples a reward from the selected machine; learning these distributions supports the exploration–exploitation trade-off. section 12.1.6
