Market success as a criterion for assessing player contributions in sports businesses via a regression-based approach using adjusted performance measures and quasi-dummy variables

Using winning percentage as a well-established proxy for market success, this article proposes a method for estimating the relative contributions of players to victories as an assessment of their worth—that is, their value to team owners or their greatness as judged by sports fans. Specifically, the proposed approach regresses winning percentage on adjusted measures of team performance (with the players of interest omitted) plus quasi-dummy variables coded to represent the participation rates of the relevant players. Though this approach lends itself to use across a wide variety of sports (professional or college football, basketball, hockey, baseball, and so on) and situations (such as season, league, and history of team), it is described primarily in the context of major league baseball and is illustrated by means of a specific empirical application to the case of the New York Yankees.