There have been 84 World Series played since 1924 using the 2-3-2 format in which the team with home-field advantage hosts the first two and last two games, and the home team has won 48 times, or 57%. (Excluded are years in which the travel format was altered because of war and 1994, when there was no World Series because of a strike.) From 1951 to 1980, the team without home-field advantage won 20 of the 30 Series, while 22 of the last 29 winners have been the team with home-field advantage.
"Baseball in general has the lowest home-field advantage of all sports," said Tobias Moskowitz, coauthor of "Scorecasting" and a professor at the University of Chicago. "We don't find that there is any difference in the postseason versus the regular season, once you adjust for the quality of teams."
Even though baseball is the one sport where the dimensions of the field vary in each ballpark, allowing teams to mold their rosters to the idiosyncrasies of their home stadiums, it is also the sport with the lowest historical home-team winning percentage. Over the last three complete seasons, the home team has won 55.5% of the 7,288 games. Over the last century, that figure has hovered around 54%.