Most football fans don't put too much thought into where the schedule for their favorite teams come from or how it is determined. They just look at it when it comes out, celebrate the easy games, moan about the tough ones, and get ready for the season. The NFL schedule formula used to determine which teams play when, though, is a surprisingly complicated formula. It doesn't really matter to sports fans or bettors in the grand scheme of things, but it's still good to know how these things work. Here, then, is the NFL schedule formula. It is obviously subject to change, though the current formula will be used at least through the end of the 2009 season.

First, the basics. Each team plays 16 games, and those take place over a 17-week schedule. That means that each team has a bye week at some point during the season. Each team is also guaranteed to play eight games at home and eight on the road.

The biggest chunk of games comes from division play. Each team plays each of the other three teams in its division twice - once at home and once on the road. That accounts for six of the 16 games.

Each team plays each of the four teams in one of the divisions in their own conference. This rotates, so every division plays every other division in their conference once every three years. Two of those four games are at home, and two are on the road.

The next four games are played against the four teams in a division in the other conference. This alternates also, so each division will play each other division in the other conference once every four years. Two of these games are at home, and two are on the road, and that will be the opposite the next time the divisions meet.

The last two games come against two teams in their conference which they are not already playing that finished in the same place in their division standings as they did - i.e. - if the AFC East is playing the AFC West, then the third place team in the AFC East would play the third place teams in the AFC North and AFC South.

Under this current system, every team plays every other team at least once every four years, and every team travels to every stadium at least once every eight years. That's relatively straight forward, but there are a couple of things that could complicate it. First, if the NFL continues to play international games like they did in London last year then the visitation of different stadiums would be unbalanced. This is guaranteed to happen even if they don't play more international games (though they are planning to), because Buffalo is now playing some regular season games in Toronto. It would also be more complicated if the NFL were to add more teams. That would make it more difficult to balance the NFL schedule. They managed it with 30 teams, though, so the league certainly won't let scheduling challenges stand in the way of a massive expansion fee if it makes sense.

Despite the system, a few scheduling oddities still exist. Most notably, Tampa Bay has never played in Buffalo. The two teams have met only rarely, and always in Tampa Bay. Buffalo in mid-winter would be a bit of a shock for a Florida team.

For the 2008 season, here are the division set-ups:

The AFC North will play the AFC South and NFC East
The AFC East will play the AFC West and NFC West
The AFC South will play the AFC North and NFC North
The AFC West will play the AFC East and the NFC South
The NFC North will play the NFC South and the AFC South
The NFC East will play the NFC West and the AFC North
The NFC South will play the NFC North and the AFC West
The NFC West will play the NFC East and the AFC East