Biased perceptions about momentum: Do comeback teams have higher chances to win in basketball overtimes?

Momentum is often cited in the media and in other sources as an important factor in performance over time in business, politics, sports and other areas. Yet, academic research on whether momentum actually exists is mixed. This study aims to assess momentum perceptions in a context in which momentum could be relevant, but where empirical data have shown that no momentum exists. In particular, we take the scenario of a basketball game that is tied at the end of regulation time. We designed questionnaires where one of the teams closed a moderate or a large score gap during the last few minutes of the fourth quarter (and in a control treatment, the score was balanced during these minutes). In the first study, 107 fans and 73 practitioners answered these questionnaires. Then, in the second study, 250 additional respondents completed questionnaires containing the same game scenarios but with additional “opposite-framing” versions and a set of questions regarding the reasons for momentum-based beliefs. The respondents also answered several questions about their level of knowledge and interest in basketball, which allowed us to categorize them to fans and laymen. The responses revealed that coming back into the game by reducing a significant score gap during the final minutes of regular time was perceived to increase the teams’ chances to win in overtime (which can be interpreted as a positive momentum). Fans exhibit stronger momentum beliefs compared to laymen. Overall, respondents’ perceptions contradict the existing empirical evidence that shows that the comeback team does not have higher chances to win the game in overtime. We discuss possible reasons for the discrepancy between the perceptions we observed and the empirical data.