PREDICTING SUCCESS USING THE NFL SCOUTING COMBINE ____________________________________ A Thesis Presented to the Faculty of California State University, Fullerton ____________________________________ In Partial Fulfillment of the Requirements for the Degree Master of Science in Clinical Psychology ____________________________________ By Andrew James Meil Thesis Committee Approval: Melinda Blackman, Department of Psychology, Chair Kristin Beals, Department of Psychology Jack Mearns, Department of Psychology Spring, 2018 ABSTRACT Professional sports organizations have been utilizing data-based approaches when selecting potential athletes increasingly over the past couple of decades, as depicted in Moneyball. The National Football League (NFL) conducts a yearly Scouting Combine in an attempt to examine top prospects’ physical characteristics and attributes that are typically sought after in the game of football. The current study focuses on whether an athlete’s performance at the Combine can predict future success at the professional level. The study examined 917 athletes that participated in the Combine from 2004 to 2009. These athletes were categorized into eight different position groups across the National Football League. Measures for the study included six physical ability tests from the Combine, height, weight, and three unique success variables. Correlations and multiple regressions were conducted to examine the impact of Combine performance on future success. Only four of the eight position groups had statistically significant predictions in the study. However, the primary finding of whether a player’s performance at the Combine was able to predict future success in the NFL based on their position is deemed questionable at best. Thus, the study suggests that NFL executives and personnel influence a statistical approach, in combination with professional judgment to account for intangibles and unquantifiable measurements, in order to select an athlete that has the most potential to be a successful player in the National Football League. ii TABLE OF CONTENTS ABSTRACT ................................................................................................................... ii LIST OF TABLES ......................................................................................................... v ACKNOWLEDGMENTS ............................................................................................. vi Chapter 1. INTRODUCTION ................................................................................................ 1 Introduction ........................................................................................................... 1 The National Football League ....................................................................... 3 NFL Scouting Combine ................................................................................. 5 NFL Combine Studies ................................................................................... 7 Purpose and Hypotheses ....................................................................................... 11 2. METHODS ........................................................................................................... 14 Methods ................................................................................................................ 14 Data Collection .............................................................................................. 14 Participants ..................................................................................................... 14 NFL Combine Physical Ability Tests ................................................................... 15 Forty-Yard Dash ............................................................................................ 15 Vertical Jump ................................................................................................. 15 Bench Press .................................................................................................... 16 Broad Jump .................................................................................................... 16 Three-Cone Drill ............................................................................................ 17 Twenty-Yard Shuttle ...................................................................................... 17 Physical Attributes ......................................................................................... 18 Success in the NFL ............................................................................................... 18 Years of Experience ....................................................................................... 18 Post-Season Accolades .................................................................................. 19 3. RESULTS ............................................................................................................. 20 Results .................................................................................................................. 20 Multiple Analysis of Variance ....................................................................... 22 Multiple Regressions .................................................................................... 22 iii 4. GENERAL DISCUSSION ................................................................................... 25 REFERENCES .............................................................................................................. 33 iv LIST OF TABLES Table Page 1. Correlations Amongst Physical Ability Tests and Success ................................. 21 2. Position-Specific Regressions .............................................................................. 24 v ACKNOWLEDGMENTS I would like to thank my parents, family, and friends for the unconditional support, encouragement, and love they continuously show me. vi 1 CHAPTER 1 INTRODUCTION Within each type of organization or business, there are unique procedures that are required when selecting potential employees. Selecting a potential employee can either positively or negatively impact the organization; therefore it is of great importance to select personnel that may benefit the organization. A selection system can be evaluated through the accuracy of the predictors being used, specifically by how well a measure correlates with performance-related criteria needed for that organization (Murphy, 2002). Generally, there are two different approaches that can be implemented within a selection process: the “statistical” approach, which involves an algorithmic combination of data, and the “clinical” approach, which is a broad term applied when a human judge evaluates available information to make a prediction (Ruscio, 2000). The discussion of whether “statistical” methods of data combination or "clinical" methods are more effective when attempting to predict behavior has been relevant for more than half a century (Ayres, 2007; Meehl, 1954). Paul Meehl (1954) tested this question and argued that the debate over whether “statistical” versus “clinical” methods yield better predictions. Meehl believe both approaches needed to be studied thoroughly and independently of the context of the prediction. Numerous studies suggest that predictions based on human judgment typically do worse than statistical formulas in regard to the efficacy of these two approaches (Ayres, 2 2007; Dawes, Faust, & Meehl, 1989; Kahneman & Tversky, 1973; Meehl, 1954). In addition, Goldberg (1991) indicates that statistical prediction is superior to clinical prediction due to the desirable properties of statistical techniques and undesirable cognitive biases of human judges. Therefore, statistical equations are seen to be more effective in identifying relationships amongst variables when compared with human judgment; whereas, the cognitive biases associated with human judges lower the accuracy of identifying significant relationships (Ruscio, 2000). In the context of professional sports, there has been an increasing necessity to incorporate statistical analysis into the decision-making of selecting potential employees, or in this context, athletes. There have been changes over the years in the evaluation of potential talent due to the advancements in technology and improvements in the accuracy of understanding which physical characteristics are measured (Wolfe, Wright, & Smart, 2006). One of the most notable uses of statistics to assist in the assessment and management of players in the business of sport can be found in Major League Baseball with the story of the 2002 Oakland Athletics, depicted in the book Moneyball: The Art of Winning an Unfair Game (Lewis, 2004). The Oakland Athletics (A’s) were attempting to break the tradition of heavily relying on talent scouts to predict future performance based on observed potential skills and physical attributes (i.e., clinical approach). In an effort to be salary cost effective, the A’s implemented a statistical approach to focus on past performance as a predictor of future performance, rather than rely on talent scouts’ “clinical experience” in selecting potential athletes (Wolfe et al., 2006). The use of statistics in the game of baseball brought a new paradigm of addressing how teams manage players by using science to 3 support decisions. This new statistical approach was labeled “Sabermetrics” by combining the acronym for the Society for American Baseball Research (SABR) and the Latin suffix for measurement. “Sabermetrics” was spearheaded