Finally, Evidence for a Momentum Effect in the NBA

No previous study on momentum in team sports has found any valid evidence for a momentum effect—i.e., an effect of success in the past few games, over and above the effect of team quality. We develop an econometric model to determine if there is a momentum effect in the NBA by examining how success over the past few games leads to a higher probability of winning the next game. The model takes into account the home vs. away strengths of the teams in the current game as well as their opponents in the previous games (to calculate measures of “adjusted success over the past few games”). Thus, success in previous games is adjusted for quality of the wins or losses. In addition, we account for rest days before the current game for both teams. Using data over three NBA seasons (2007-2009), we find strong evidence for a positive momentum effect.

[1]  John Goddard,et al.  Forecasting football results and the efficiency of fixed‐odds betting , 2004 .

[2]  Perceptions of Psychological Momentum and Their Relationship to Performance , 1991 .

[3]  M. Bar-eli,et al.  Twenty years of “hot hand” research: Review and critique , 2006 .

[4]  R. A. Bradley,et al.  Rank Analysis of Incomplete Block Designs: I. The Method of Paired Comparisons , 1952 .

[5]  R. Kelly Crace,et al.  Analysis of Psychological Momentum in Intercollegiate Tennis , 1988 .

[6]  E. McAuley,et al.  Perceptions of Causality in Sport: An Application of the Causal Dimension Scale , 1983 .

[7]  David J. Berri,et al.  Stumbling On Wins: Two Economists Expose the Pitfalls on the Road to Victory in Professional Sports , 2009 .

[8]  Trevon Logan,et al.  Does the Hot Hand Drive the Market? Evidence from Betting Markets , 2011 .

[9]  Jeremy Arkes,et al.  Revisiting the Hot Hand Theory with Free Throw Data in a Multivariate Framework , 2010 .

[10]  K. Mobily,et al.  “Psychological Momentum”: A Phenomenon and an Empirical (Unobtrusive) Validation of its Influence in a Competitive Sport Tournament , 1980 .

[11]  R. Nickerson,et al.  The production and perception of randomness. , 2002, Psychological review.

[12]  Roger C. Vergin,et al.  Winning Streaks in Sports and the Misperception of Momentum , 2000 .

[13]  Daniel M. Oppenheimer,et al.  The retrospective gambler’s fallacy: Unlikely events, constructing the past, and multiple universes , 2009, Judgment and Decision Making.

[14]  S. Redner,et al.  Understanding baseball team standings and streaks , 2008 .