Berger & Pope reported NBA teams slightly behind at halftime were 5.8–8.0 percentage points more likely to win, attributing it to loss aversion among experts

Berger & Pope's "Can Losing Lead to Winning?" (Management Science, 2011) analyzed NBA game data and found that teams "slightly behind at half-time are between 5.8 and 8.0 percentage points more likely to win the match than those that are slightly ahead." Being marginally behind at the temporal midpoint, in other words, raised rather than lowered win probability — a counter-intuitive reversal concentrated at small halftime margins.

The authors attributed the reversal to loss aversion: a halftime scoreline functions as a reference point, and trailing teams, framed as facing a loss, exert extra effort. The study became widely cited because it located the effect in professionals rather than lab subjects — it is "regarded as one of the first studies to show that loss aversion is not limited to inexperienced subjects in low-stakes settings, but also affects the behavior of experts in a high-stakes professional environment."

This is the sports-competition face of the same reference-point-plus-loss-aversion engine (claim-goals-as-reference-points-below-goal-work-harder) that drives the individual Fresh Start Effect and Gersick's group-level midpoint transition — three domains, one mechanism. Its status as a robust finding, however, did not survive a broader replication: the effect largely vanishes outside the original NBA sample (claim-losing-leads-to-winning-fails-to-replicate-across-four-sports). See moc-schema-change-and-restructuring.

The figure is now confirmed directly against Berger & Pope's own paper text, not only the 2023 replication's restatement of it — see claim-berger-pope-2011-ncaa-halftime-effect-smaller-than-nba for the smaller NCAA analogue reported in the same paper, and claim-berger-pope-lab-experiment-isolates-loss-aversion-from-winning-team-complacency for the authors' own laboratory test of the mechanism. question-verify-berger-pope-2011-halftime-loss-aversion-primary, which routed this verification, is now answered.