Eur. Phys. J. B 67, 473-481 (2009)
https://doi.org/10.1140/epjb/e2008-00405-5

Understanding baseball team standings and streaks

¹ Laboratoire de Physique Théorique - IRSAMC, CNRS, Université Paul Sabatier, 31062 Toulouse, France
² Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts, 02215, USA

Corresponding author: ^a uebing@mpie-duesseldorf.mpg.de

Received: 29 July 2008
Revised: 8 October 2008
Published online: 5 November 2008

Abstract

Can one understand the statistics of wins and losses of baseball teams? Are their consecutive-game winning and losing streaks self-reinforcing or can they be described statistically? We apply the Bradley-Terry model, which incorporates the heterogeneity of team strengths in a minimalist way, to answer these questions. Excellent agreement is found between the predictions of the Bradley-Terry model and the rank dependence of the average number team wins and losses in major-league baseball over the past century when the distribution of team strengths is taken to be uniformly distributed over a finite range. Using this uniform strength distribution, we also find very good agreement between model predictions and the observed distribution of consecutive-game team winning and losing streaks over the last half-century; however, the agreement is less good for the previous half-century. The behavior of the last half-century supports the hypothesis that long streaks are primarily statistical in origin with little self-reinforcing component. The data further show that the past half-century of baseball has been more competitive than the preceding half-century.