For those that followed along the 2015 season, I started a spreadsheet that chronicled the numbers of a team's offense, defense, and special teams units. At first, I tested the formula for 2014 which had the Patriots the #1 team and the Seahawks the #2 team. In 2015, the spreadsheet was also able to correctly predict all 12 playoff teams, although the Jets were the only top 12 team to miss the playoffs and the Texans were the only team out of the top 12 that made the playoffs. Due to the success of that spreadsheet last season, it will make a return. Here's how the calculations goes (WARNING: Contains a lot of math, but nothing super complicated)
Strength of Schedule:
Strength of schedule usually determines whether a team feasted on weak competition whereas taking a tough schedule and running through it. The schedule score comes from both the team's individual record when compared to league average and the opponent's strength of schedule outside of the W-L record of that individual team. Both individual win % and win % of the strength of schedule are compared to the league average of .500. League Average is then set to 50. In addition, there is a strength of victory. It works just like strength of schedule, but only include the records of the teams they beat.
Offense/Defense:
Points per game is a terrible statistic to use when judging the productivity of an offense. Points are a volume stat and is too dependent on too many factors to be reliable. Instead, the metric used for scoring is Points per Drive (PPD). In addition, a successful offense is able to limit turnovers and end drives in the end zone. For that, scoring and turnover % on a per drive basis is also used as part of the offensive score. The key to sustaining drives for scores is also the ability to gain chunk yardage. That is why yards per play is included.
Special Teams:
Special Teams may be the most difficult unit to grade of the four. Special Teams units depend on field position, punt coverage, kick coverage, as well as returns. Field position is very crucial, as good teams have positive field position (offense starts closer to the end zone than the defense). The saying is 20 yards extra of field position is worth 1 point, and a +5 field position over 16 games grades out to an extra 48 points over the season. That's enough to change maybe 2-3 games over the course of the season since the best teams in the league wind up averaging 30 points a game.
Top kick coverage units will get touchbacks and limit the damage on returns. Top punt coverage units will limit the damage on returns and consistently pin opponents into poor field position. Punters that can pin their opponents consistently inside the 20 put their defense at an advantage and indirectly leads more points on offense or off a turnover. Kick return grades are a bit flimsy as they depend on the number of returns and kick returns aren't really part of the game.
Total Score and Ranking Teams:
The team score for all 4 phases depends on snaps. The snap counts for offense, defense, and special teams are needed to determine a weighted average of the team score before taking the average of that and the schedule score. The ranked tiers come from the average and standard deviance of the team data. The tiers are Great, Good, Average, Bad, and Terrible. The distribution of these different tiers should be similar to a normal distribution curve.
Conclusion:
Whether or not you decide to use this as a way to judge teams around the league and who the best opponents are for the Patriots is up to you. I've seen too many times where the pundits keep citing stats that depend on too much luck and not enough credit from the other teams. Statistics don't tell the entire story, especially when factoring sample sizes but I try to use ones that measure the productivity of an offense as supposed to production.