The Captain Class: The Hidden Force that Creates the World's Greatest Teams

Walker acknowledges how challenging it is to determine which teams in history truly deserve to be called the greatest. Rather than accepting existing rankings—which the author discovered were often plagued by selection bias, regional favoritism, and statistical inadequacies—Walker embarked on an ambitious empirical project to identify history’s most dominant teams across all major sports worldwide.

Walker’s methodology reveals both the rigor of modern sports analytics and its inherent limitations. His systematic approach involved establishing clear criteria for what constitutes a team (at least five members who interact directly with opponents and each other), eliminating teams that lacked sufficient opportunity to prove themselves against top competition, and requiring sustained excellence over at least four seasons to minimize the influence of luck. 

Walker used the Elo rating system—originally developed for chess and adapted for sports—as his primary evaluative tool. The Elo method is a mathematical method that assigns teams a running score based on their wins and losses but adjusts these points based on the quality of their opponents and the importance of each match. For example, beating a top-ranked team in a championship final earns far more points than defeating a weak team in a friendly exhibition game. Walker’s decision to use the Elo method reflects the growing sophistication of sports analytics.