http://www.nfl.com/standings/tiebreakingprocedures
It is # 6 on the list above. You look at the points scored ranking within the conference (1-16) and add that ranking to the defense score allowed ranking (1-16). The combined number is compared.
- Head-to-head, if applicable.
- Best won-lost-tied percentage in games played within the conference.
- Best won-lost-tied percentage in common games, minimum of four.
- Strength of victory.
- Strength of schedule.
- Best combined ranking among conference teams in points scored and points allowed.
- Best combined ranking among all teams in points scored and points allowed.
- Best net points in conference games.
- Best net points in all games.
- Best net touchdowns in all games.
- Coin toss.
For example the Dolphins and the Colts. The Dolphins are 13th in points scored and 12th in points allowed for a combined ranking of 25.
The Colts are 14th in points scored and tied for 15th in points allowed for a combined ranking of 29. The Dolphins are combined ranking is higher.
So the Dolphins and the Colts are tied at 0-3 and both are 0-2 in the conference. They do not have 4 common games. Neither has Strength of Victory because they haven't won. Their Strength of Schedule is tied. Then you look at the combined rankings.