San Francisco and New England looked like teams playing on a different level than everyone else a few weeks ago. Both started to face stiffer competition and have come back to the pack.
No two teams among the top fifteen have lost as much team strength over a three week period as those two. They both had some buffer given how much better they were performing than the rest of the league, but in the case of the 49ers, that buffer is gone. The Patriots have managed to hold the top spot, but the Ravens are climbing like a Taylor Swift single.
Seattle managed to gain some team strength over their bye week on the backs of their strength of schedule improving as past opponents continued to play well.
Minnesota has a strikingly similar profile to the Seahawks with a highly efficient passing game and a good running game. What separates the Vikings from the Seahawks right now is a better defense. Seattle has played a tougher schedule.
The Seahawks now face an Eagles squad that gave top-ranked New England everything they could handle this week.
This view shows tiers of strength that develop over the course of the season.
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) As of September 23, 2014, I have added a strength of schedule component to the rankings as well. As of November 22, 2016, I have increased the weighting of the run game and point differential. Yards per carry will be multiplied by 10 to make it more evenly weighted with the passer rating. It is still roughly half as important, but will have a greater impact. Point differential will be multiplied by two as it still should be among the most important aspects of measuring teams.