Originally Posted by anewman35
I wouldn't assume that. There have been plenty of examples where teams (that weren't 'rivals') played year after year for no real reason (like, this is just off the top of my head but I know the Sox have played Pittsburgh a LOT), and not played teams you'd think they were due to play.
The unbalanced divisions caused some of that havoc, though, in the past, where there couldn't be a simple formula to make sure all teams played each other on a regular basis. Now that each league has 15 teams, I believe there is going to be a regular rotation of the other league's divisions for interleague. Kind of wish they could work it so you'd get each team at home every 3 years, but I guess this is the model the NFL uses and the league somehow makes it work...