If you've been reading my blog from the beginning (5 November 2003), you know that I have written many times about so-called home-field advantage. A few years ago, Bud Selig (the commissioner of Major League Baseball) announced that the winner of the mid-season All-Star game would get home-field advantage in that year's World Series. This stunned me, because I had never in my life heard anyone say, or even imply, that there was a home-field advantage in the World Series, the format of which has long been AABBBAA. The first two games are in the park of team A, the next three in the park of team B, and the final two in the park of team A. (It's best of seven.)
When I denied that there is a home-field advantage in the World Series, people criticized me, claiming that there is. Some even did a calculation of the extent of the advantage. For a while, I thought this was correct and that I was wrong, which is why I stopped writing about it. I now think I conceded too early. The reason I conceded too early is that I didn't understand my own claim!
Let me state my original argument. We know, before a World Series begins, that it will go either four, five, six, or seven games. Suppose it goes four. Then each team will have played two games in its own park. No advantage. Suppose it goes five. Then team A will have played two games in its own park and team B three in its park. Advantage B. Suppose it goes six. Three games apiece; no advantage. Suppose it goes seven. Advantage A (four games to three). That's (1) no advantage, (2) advantage B, (3) no advantage, and (4) advantage A. Since we don't know in advance how many games the series will go, there is no overall advantage.
That was my argument. The person in question disputed my reasoning, claiming that since there is in fact a home-field advantage (on a game-by-game basis), the team that starts at home has an advantage. I admit that there is a substantive (as opposed to a formal) home-field advantage. In fact, I just examined the final standings for 2009. The home team won 54.8% of the games (1333-1097). The person in question plugged this percentage into his equation and concluded that there is indeed a home-field advantage with the AABBBAA format.
What happened is that I lost sight of my claim. What I want to say is that the format per se doesn't confer an advantage on either team. It is only the format conjoined with the fact of home-field advantage (what I am calling a substantive home-field advantage) that confers an advantage on the team that starts the series at home. Do you see the difference? I'm talking about the form or structure of the series, not the substance or the substance conjoined with the form or structure.
Not all formats are neutral like the AABBBAA format. Take the format AAABBBA. This clearly confers a structural advantage on team A. Apply the reasoning above. In a four-game series, A has the advantage. In a five-game series, A has the advantage. In a six-game series, there is no advantage. In a seven-game series, A has the advantage. That's three advantages for A and none for B. Overall advantage for A. This advantage is structural.
If Major League Baseball wanted a robust home-field advantage for one of the teams, it could change the format to AAABBBA or something else. By leaving the format at AABBBAA, Major League Baseball minimizes the overall home-field advantage. In fact, it chooses a format that confers no advantage at all! Do you follow me?
Addendum: Let me be as pithy as possible. Both formats—AABBBAA and AAABBBA—confer a home-field advantage on team A, given a substantive home-field advantage. I never meant to deny that. If I denied it, it was because I hadn't distinguished in my own mind between formal and substantive advantages. The second format, qua format, does indeed confer a home-field advantage on team A. I hope you can see that. The first format, qua format, confers no home-field advantage. That is what I was trying to say all along.
Addendum 2: I came up with an even pithier formulation. The home-field advantage conferred by AAABBBA has two components, which can be analytically separated: formal and substantive. The home-field advantage conferred by AABBBAA has one component: substantive. There will always be a substantive home-field advantage in any series, whatever the format. There will not always be a formal home-field advantage. Major League Baseball has chosen the format with the least possible overall home-field advantage (where "overall" means substantive plus formal). If Bud Selig wants the All-Star game to be even more meaningful than it is, he should change the World Series format to AAABBBA, or, God forbid, AAAABBB.
Keith Burgess-Jackson, J.D., Ph.D. 