The fact that the Texas Rangers just won 11 consecutive road games on their way to a World Series title sparked a discussion at JoeBlogs about how baseball’s home field advantage has changed over time. Skinny Pete was kind enough to pull the data, so I turned it into a chart:
While there’s plenty of variance, there’s a steady drop in the home field advantage over time (R=-.224, if you’re interested).
Why does it trend downward over time? My guess is that the ongoing increase in bullpen use (with fewer tired pitchers late in the game) counteracts what I believe is the main component of the home field advantage, the strategic advantage of batting last. What do you think?