The fatal flaw in this argument is that p=.5. That is wishful thinking, I'm afraid. I think that's a pretty reasonable figure, based off the preseason expectations for each of the teams involved and taking into account their performance in the 2008 season so far (ignoring protential pitching matchups). What we are looking for is an estimate of a team's true collective talent. We can then compare the talent of each team, adjust for home field advantage and get a reasonable estimate for a series of games (for one game, the pitching matchups can have a huge effect on the probabilities). If you start talking about the Brewers not playing well at particular parks, or how the Brewers have done against a particular team in 3 games, you are going down the wrong path. That's the kind of splits that fans and gamblers get hung up on but the odds makers know to largely ignore.