In many experimental settings, individuals appear to either underreact or overreact to information when making decisions about the future. Less is known about how individuals react to information when making decisions in naturalistic settings. In this paper, I study how individual decision makers react to information about past outcomes when making judgements about future outcomes in naturalistic settings using data on elite sports. In the setting under observation, fans make hundreds of predictions about the future performance of elite athletes. Using variation in outcomes between athletes who took actions with the same probability of success, I show that persistence in the data generating process is correctly incorporated by fans into their predictions. Not only do fans react to information in the correct direction, but they also appear to react with the correct magnitude. This is consistent with fans rationally reacting to information.