A Bayesian Approach to In-Game Win Probability in Soccer Pieter Robberechts Jan Van Haaren Jesse Davis
[email protected] [email protected] [email protected] KU Leuven, Dept. of Computer KU Leuven, Dept. of Computer KU Leuven, Dept. of Computer Science; Leuven.AI Science; Leuven.AI Science; Leuven.AI B-3000 Leuven, Belgium B-3000 Leuven, Belgium B-3000 Leuven, Belgium Premier League - 2011/12 3 : 2 1:0 1:1 QPR 1:2 2:2 3:2 100% City wins 80% 60% Draw 40% 20% QPR wins 15 30 HT 60 75 90 min Figure 1: In-game win probabilities for the game between Manchester City and Queens Park Rangers (QPR) on the final day of the 2011/12 Premier League season. ABSTRACT demonstrates that our framework provides well-calibrated proba- In-game win probability models, which provide a sports team’s bilities. Furthermore, two use cases show its ability to enhance fan likelihood of winning at each point in a game based on historical experience and to evaluate performance in crucial game situations. observations, are becoming increasingly popular. In baseball, bas- ketball and American football, they have become important tools CCS CONCEPTS to enhance fan experience, to evaluate in-game decision-making, • Mathematics of computing ! Probabilistic inference prob- and to inform coaching decisions. While equally relevant in soccer, lems; Variational methods; • Computing methodologies ! Ma- the adoption of these models is held back by technical challenges chine learning; • Information systems ! Data mining. arising from the low-scoring nature of the sport. In this paper, we introduce an in-game win probability model for KEYWORDS soccer that addresses the shortcomings of existing models.