“Form is temporary, class is permanent†: an English Premier League analysis

The outcome of a contest depends on the relative resources brought to bear in the contest by each side. This observation is the mainstay of the economic theory of contests (see e.g. Corchón (2007) and Van Long (2015)). This theory has a natural application to sporting contests such as Association football (see e.g. Szymanski (2003)). It is now fairly uncontroversial to argue that team resources in football can be measured by wage payments (e.g. Peeters and Szymanski (2014)) or public estimates of player transfer values, which are closely correlated with salaries (Szymanski (2013)). That is because there is a well-developed market for players, with many buyers and sellers who are well informed about player abilities (because players perform often and in public), and hence most of the problems typically associated with asymmetric information in labour markets are absent. "Form is temporary, class is permanent" is a sporting cliché, sometimes attributed to the legendary Liverpool manager of the 1960s and 1970s, Bill Shankly. In our context, "class" may be thought of as the perceived ability of a player, which determines the salary agreed under contract. Without questioning the truth of the cliché, "form", broadly defined, also plays a role in determining the outcome of a sporting contest. In this chapter we examine various ways of defining form, which may contribute to the outcome of football matches. Specifically, we define a narrow version of form as the outcome of the previous five games played by each team. In addition we define team "sharpness" as the number of consecutive games played by each player in the last five games, and team "cohesion" as the number of players who have appeared as starters in the previous five games. While these factors are largely under the control of the coach, we consider two factors over which they have less control. One is the distance to be travelled by the visiting team, which is completely beyond the control of the team. The other is the amount of rest time of the starting players since the previous game (up to a maximum of 77 days - one week for each starter). While the coach has some control over this, through selection, scheduling constraints are externally imposed.