Revisiting the Balanced Book Hypothesis – Bettor Preferences and Results in the NFL

Abstract

Data on betting percentages, both in terms of number of bets and actual money wagered, is still difficult to find.  Sports Action Network, in their premium access service, does provide this data in terms of both number of bets and money bet.  For the2020 NFL season, it was found that the balanced book could be rejected as bettors were shown to prefer road favorites, big favorites, and the over at the highest totals.  Allowing this imbalance in the sides market appeared profitable for the book as the underdog won more often than implied by efficiency, while totals were evenly split.