When the drew up the rotating schedule for the current alignment, the league simply put the first two teams in each division in one group, and then the last two in another group, all alphabetically, to decide which teams play home-or-away in round robin play vs other divisions.
Thus, Buffalo and Miami will always have the same home and away games versus common opponents, and the Jets and the Pats will always have the opposite of them, and the same as each other. Check any schedule since 2002 and you will see this is true.
Unfortunately, it didn't occur to the schedulers not to group San Francisco and Seattle together (the order of NFC West team uses Saint Louis spelled out, thus Arizona and Saint Louis in one group, San Francisco and Seattle in the other). Thus, once every 8th season, the Pats will have games in both San Francisco and Seattle.
Ditto for Oakland and San Diego. Once every 6th season, the Pats will have games in both Oakland and San Diego (this happened in 2002; it's now 6 years later).
In 2008, we get the double whammy... both of the events will occur! This will take place every 24th season. however, chances are things will change in terms of numbers of teams and and/or divisional alignments by 2032.
