Do Sportsbooks Accurately Price Money Line Odds?

Overview

This study examines pricing efficiency in NFL gambling markets by comparing bettor profitability across spread and money line odds. The research utilizes a comprehensive dataset encompassing both market types to identify systematic divergences in expected returns between functionally similar betting strategies applied to different odds structures.

Methods and approach

The analysis employs empirical betting simulations using actual NFL gambling data containing both spread and money line quotations. The methodology constructs identical betting strategies—wagering fixed amounts on favorites and underdogs across all games—and measures realized returns separately for spread and money line markets. The study systematically partitions outcomes by spread magnitude to identify conditional profitability patterns and potential arbitrage opportunities within the money line market.

Key Findings

Naive betting strategies reveal asymmetric loss profiles across market types. A $110 wager on favorites against the spread generates average losses of $4.50 per game, while money line favorites produce losses of $4.53 per game. Underdog betting demonstrates greater divergence: spread market underdog wagering yields $3.11 average losses per game, whereas money line underdog betting produces negligible losses of less than $0.01 per game. Conditional analysis reveals profitable money line underdog strategies dependent on spread magnitude, with returns of 2.17% when closing spreads fall between 3 and 7 points, and 6.55% when spreads are 3 points or less.

Implications

The observed profitability differentials between spread and money line markets contradict strong-form market efficiency assumptions in sports gambling contexts. Sportsbooks appear to misprice money line odds relative to spread odds, creating exploitable discrepancies. The magnitude of identified returns—particularly the 6.55% conditional profitability—suggests systematic mispricing rather than random pricing variation. These findings indicate potential optimization opportunities in sportsbook pricing mechanisms and challenge prevailing assumptions regarding market-wide efficiency in sports betting equilibrium.