The 'losing leads to winning' halftime effect fails to replicate outside Berger & Pope's original NBA window, across four sports

Klein Teeselink, van den Assem & van Dolder (Management Science 69(1), 2023) re-examined the celebrated finding that being slightly behind at halftime raises a team's win probability (claim-berger-pope-nba-halftime-deficit-raises-win-probability) by extending the test to four sports. The effect largely evaporated.

Across Australian football, American football, and rugby the authors report "no evidence of such an effect for these three sports." For basketball, the original result survives narrowly: support persists "only… for NBA matches from the period analyzed in Berger and Pope (2011)" — not later NBA seasons, not NCAA, not the WNBA. Pooling the evidence, "high-powered meta-analyses across the different sports and competitions do not reject the null hypothesis."

The finding matters because the halftime-deficit effect was one instance of a broader claimed pattern — a temporal landmark creates a reference point, and being below it triggers loss-aversion-driven effort — shared with the individual Fresh Start Effect and Gersick's group-level midpoint transition. All three run on the same engine, goals as reference points plus loss aversion. That the most stress-tested member of the family is confined to a single league in a single decade is evidence that the engine does not fire reliably in every setting where a landmark and a deficit co-occur. It rhymes with the vault's other cautions against era- and sample-bound effects surviving reframing (see observation-deep-learning-rebrand-as-field-scale-fresh-start) and belongs to the moc-schema-change-and-restructuring cluster on when a boundary actually reorganizes behavior.

The primary-source read behind Berger & Pope's original figure remains open at question-verify-berger-pope-2011-halftime-loss-aversion-primary.