EDITOR’S NOTE: NEW RANKINGS FORMULA
I rarely tinker with my rankings formula. It has proven a useful indicator of team strength, even early in the season. A few years ago I replaced yards per attempt with passer rating because of the historical significance of passer rating differential when it comes to Super Bowl winners. I also liked that it was a more holistic measure of offensive and defensive pass efficiency. More recently, I added in strength of schedule (SOS) because performance without consideration of who it was achieved against is only part of the story. I was not entirely satisfied with the formula because it left the run game almost irrelevant to the rankings.
Passer ratings range from the 60s to over 100. Yards per carry in the running game range from 2.0 to 6.0. Leaving those two numbers unweighted basically meant the running game was about 10X less important, which I don’t believe to be true. That was demonstrated this season as a team like Dallas was consistently outside the top ten in the rankings. Much of that was due to their SOS being among the worst in football, but their strong run game was not getting the credit it deserved.
POWER RANKINGS
Watch out for the Atlanta Falcons. They admittedly just played the Rams and 49ers, but putting up 40+ points in two straight weeks without the services of Julio Jones is an impressive feat against any NFL opponent. There are few other teams sprinting to the finish the way they are. Defense remains a big question mark, as they are allowing nearly 26 points per game, a 96.9 opponent passer rating, and 4.4 yards per rush. That offense, though, is overpowering nearly every team they face. Seahawks fans owe the Chiefs a debt of gratitude for their recent victory over the Falcons. Without that, Atlanta would have a much better shot at finishing with the second seed.
Seattle has fallen back a ways since their blowout loss to the Packers. They had risen to second a couple weeks ago. The defense continues to keep the team afloat, but the offense has been unable to escape mediocrity. The next two weeks are all about the Seahawks finding some consistency and confidence on offense.
Scatter chart
I like this view as it shows tiers of strength that develop over the course of the season.
RANKINGS EXPLAINED
Power rankings are always debatable. I don’t buy into the gut feel methods most places use to determine their rankings, so I developed a formula a few years back that attempts to take at least some of the subjectivity out of the discussion. My approach was simple, I measured offensive and defensive efficiency based on the Yards Per Carry (YPC) and Yards Per Attempt (YPA), as well as points scored and points allowed. The formula to calculate “Team Strength” was as follows:
(YPC (offense) + YPA (offense) + Avg Pts/Game Scored) – (YPC (defense) + YPA (defense)+ Avg Pts/Game Allowed)
The formula has proven to be a pretty accurate predictor of success (roughly 70% of the teams ranked in the Top 10 by week 3 make the playoffs), but I am always looking for ways to improve it. I read a great article on ColdHardFootballFacts.com. There was one gem in there about predicting championship teams. The article mentioned passer rating differential as the “mother of all stats.” A full 69 of 72 champions have ranked in the Top 10 in this statistic. It is a stat after my own heart, as I believe offensive and defensive efficiency is the key measurable outside of point differential. Turnovers would factor in there as well, but I am not convinced a team has as much control over that. My power rankings use YPA and YPC differentials. I went ahead and replaced the YPA with offensive and defensive passer rating, to give me this:
(YPC (offense) + Passer Rating (offense) + Avg Pts/Game Scored) – (OPP YPC (defense) + OPP Passer Rating (defense)+ OPP Avg Pts/Game)