In the book Scorecasting by Moskowitz and Wertheim,1 we learn that "Across 43 professional soccer leagues in 24 different countries spanning Europe, South America, Asia, Africa, Australia, and the United States (covering more than 66,000 games), the home field advantage [percent of games won by the home team] in soccer worldwide is ." What is the relevant statistical parameter, including correct notation? Your answer should be an expression composed of