Predicting sporting outcomes: a statistical approach Michael J. Bailey MSc(Statistics), BSc(Hons) A thesis submitted for the degree of Doctor of Philosophy Faculty of Life and Social Sciences Swinburne University of Technology March 2005 Acknowledgments Prior to the commencement of this doctorate, I was fortunate enough to spend two years as a sports statistician for the Swinburne Sports Statistics department. It was during this period of time that much of the inspiration for this thesis was derived and I would like to thank both the Swinburne Department of Mathematical Sciences and more specifically the Swinburne Sports Statistics department for this opportunity. I would like to thank Swinburne for offering a Swinburne University Post Graduate Research Award (SUPRA), and the Department of Education, Science and Training for ultimately providing an Australian Postgraduate Award (APA) to fund this body of work. To my beautiful wife and daughter, Rochelle and Isabella, thank you greatly for your love, patience and understanding. I would like to thank my father Bernard Bailey for his proof reading skill and astute comments. I would like to thank my supervisors Julie Pallant and Stephen Clarke. In particular, it has been Steve’s knowledge, humour, insight, persistence and tolerance that have made this dissertation possible. ii Candidate’s statement This document contains no material which has been accepted for the award to the candidate of any other degree or diploma, except where due reference is made in the text of the thesis. To the best of my knowledge, this document contains no material previously published or written by another person except where due reference is made in the text of the thesis. Unless acknowledged, all work found in this thesis has been done by the candidate. Michael J. Bailey iii Preface Three of the six analysis conducted in this dissertation have resulted in refereed publications. Of the four publications that have arisen from this work, one was published solely by the author; the other three as a result of the authors work, under the knowledgeable guidance of my supervisor Stephen Clarke. The first analysis conducted, predicting the outcome of AFL matches, has resulted in two publications. The first of these publications was written solely by the author in the year 2000 and provides an early insight into development of the modeling process. (Bailey, M. (2000). Identifying arbitrage opportunities in AFL betting markets through mathematical modeling. Proceedings of the Fifth Australian conference on Mathematics and Computers in Sport. G. Cohen and T. Langtry. Sydney, University of Technology Sydney: 37-42). The second publication relating to the prediction of AFL matches was written four years later under the supervision of Stephen Clarke and forms the nucleus of the analysis presented in chapter four of this dissertation (Bailey, M., J, and Clarke, S. R. (2004). Deriving a profit from Australian Rules football: A statistical approach. Proceedings of the Seventh Australian conference on Mathematics and Computers in Sport. Palmerston North, Massey University, R Hugh Morton & S Ganesalingam: 48-56). The conference presentation of this analysis resulted in an award for best student presentation. In chapter seven of this thesis, the prediction of batsmen performance in limited overs cricket is presented. Under the guidance of Stephen Clarke, this analysis was published as a refereed book chapter in 2004. (Bailey, M. J. and S. R. Clarke (2004). Market Inefficiencies in player head to head betting on the 2003 cricket world cup. Economics, Management and Optimization in sport. S. Butenko, J. Gil-Lafuente and P. Pardalos. Heidelberg, Springer-Verlag: 185-201.) iv In chapter eight, the prediction of the Brownlow medal winner in AFL football is discussed. Several media and academic articles have resulted from this body of work, the most notable of which being a refereed conference paper that was once again written under the guidance of my supervisor Stephen Clarke. This analysis has since been superceded, but provides much impetus for the results presented in this dissertation. (Bailey, M. J. & Clarke, S. R. (2002). Predicting the Brownlow medal winner. Proceedings of the sixth Australian conference on mathematics and computers in sport. G. Cohen and T. Langtry. Bond University, University of Technology, Sydney: 56-62.) v Table of contents Acknowledgments ............................................................................................................. ii Candidate’s statement .....................................................................................................iii Preface............................................................................................................................... iv Table of contents .............................................................................................................. vi List of Figures................................................................................................................... xi List of Tables ..................................................................................................................xiv Table of abbreviations .................................................................................................... xv Abstract........................................................................................................................... xvi 1 Introduction ................................................................................................................ 1 2 Background and literature review............................................................................ 4 2.1 Australian Rules football....................................................................................... 4 2.2 Cricket ................................................................................................................... 7 2.3 Predicting sporting outcomes.............................................................................. 10 2.4 Home advantage.................................................................................................. 11 2.5 Market efficiency ................................................................................................. 12 3 Methodology ............................................................................................................. 17 3.1 Background.......................................................................................................... 17 3.2 Data ..................................................................................................................... 18 3.3 Underlying distribution ....................................................................................... 20 3.4 Identifying significant predictors......................................................................... 22 3.5 Holdout sample.................................................................................................... 23 3.6 Multivariate model building ................................................................................ 24 3.7 Accuracy of prediction......................................................................................... 25 3.8 Bookmaker prices ................................................................................................ 26 3.9 Converting predicted outcomes into probabilities .............................................. 27 3.10 Wagering strategy................................................................................................ 28 3.11 Statistical analysis............................................................................................... 29 vi 4 Predicting the match result in AFL football.......................................................... 30 4.1 Introduction ......................................................................................................... 30 4.2 Background.......................................................................................................... 30 4.3 Predictors of MOV for AFL football ................................................................... 32 4.3.1 HA in AFL football....................................................................................... 32 4.3.2 Travel fatigue................................................................................................ 33 4.3.3 Ground familiarisation.................................................................................. 33 4.3.4 Measures of performance.............................................................................. 34 4.4 Bookmaker prices ................................................................................................ 38 4.5 Method................................................................................................................. 39 4.6 Results.................................................................................................................. 41 4.6.1 Trends over time ........................................................................................... 43 4.7 Discussion............................................................................................................ 45 5 Predicting the match result in ODI cricket............................................................ 47 5.1 Introduction ......................................................................................................... 47 5.2 Background.........................................................................................................