An Introduction to the NerdBall Efficiency Rankings (NEFF)

Welcome to the NerdBall Efficiency Rankings (NEFF), a set of rankings that give an analytical take of a multitude of facets of NFL play, with an aim to identify the best and worst performing teams throughout the NFL season. I’ve been developing these rankings over a number of years and in this overview I will demonstrate how each of them are put together, give you some historical data points of good and bad performances, and share my view on how you can make the best use of the data to support your fantasy teams, or just your general football knowledge in the season ahead.

Team NEFF Rankings

I start with the total team NEFF rankings, my blue chip grading system that provides both a weekly and season long rating for each team’s performance, broken into a total team rating, plus one for their offense, defense and special teams. The rankings are derived from over 40 statistical metrics from each game, which have been calibrated and weighted based on the relationship of that metric to a team’s likelihood of winning to shape the grade for each of the phases of play.

The grades are also weighted so that games later in the season carry more influence on the outcomes, both to account for the strength of the opponent faced and the fact that games later in the season are more important in shaping which teams make the post season.

As well as completing the gradings for the current season, I am also adding more years to the ranking history and have recently completed an analysis of the 2006 season. This now means I have a complete record of graded games for the past 15 seasons, some 3,800+ individual game grades in total, so I will be looking to provide historical context to what we see in the new season.

The ratings themselves will be published every Wednesday during the season, and I will highlight any interesting statistical points that may help with the following week’s match ups from a fantasy football and DFS perspective.

NEFF Rating System

The rating system itself runs between 100% and -100% for each phase of the game, with offense and defense contributing each just over 43% of the overall team grade, with special teams the remaining 13%.

As you might expect, over the course of the years I have graded NFL games, there have been very few ‘perfect’ 100% rated games, with just 24 over the course of the last 15 seasons. The last such game came last season when the eventual Super Bowl champion Tampa Bay Buccaneers defeated the Detroit Lions 47-7 in Week 16. Only 19 teams have achieved a +100% rating in the last 15 years, and within that, only 3 teams have multiple perfect games: the New England Patriots and Baltimore Ravens with 3 and the Philadelphia Eagles with 2.

There have been 34 instances of a team recording a -100% rating, with the Rams (St Louis version) leading the way with 4 such ratings, all of which occurred across the 2007 and 2008 seasons.

Perfect NEFF Ratings 2006-2020
202016Buccaneers@ Lions47 - 7
20191Ravens@ Dolphins59 - 10
20192Patriots@ Dolphins43 - 0
201811Saintsvs Eagles48 - 7
201817Eagles@ Redskins24 - 0
20171Ramsvs Colts46 - 9
201715Jaguarsvs Texans45 - 7
20149Dolphinsvs Chargers37 - 0
20133Panthersvs Giants38 - 0
2012549ersvs Bills45 - 3
201214Seahawksvs Cardinals58 - 0
201116Steelersvs Rams27 - 0
201013Patriotsvs Jets45 - 3
201014Chargersvs Chiefs31 - 0
20093Ravensvs Browns34 - 3
20096Patriotsvs Titans59 - 0
20097Packers@ Browns31 - 3
200914Ravensvs Lions48 - 3
20081Eaglesvs Rams38 - 3
20085Giantsvs Seahawks44 - 6
200810Jetsvs Rams47 - 3
20074Cowboysvs Rams35 - 7
200714Broncosvs Chiefs41 - 7
20064Chiefsvs 49ers41 - 0
Team NEFF Rankings – Leading Ratings 2006-2020

Looking back over the last 15 years, we have seen quite a variation in the final grade of the top performing team in the NFL each season, and though every team to finish first has made the playoffs that season, only one has gone onto win the Super Bowl in the same year, the 2016 New England Patriots.

The all-time greatest team I’ve graded was the 2007 Patriots, whose 16-0 regular season record translated into a grade of +42.2%, over 10% higher than any other team I’ve ever graded. They remain the only team to have ever finished with the top rated offense (+60.5%) and defense (-25.3%) in the same season in my rankings, though neither of these ratings were the best I’ve graded over the past 15 years.

When looking at the best team over the course of the 15 years for which I have graded NFL teams, the Patriots also sit atop the rankings with an average rating of +15.0%. After the Patriots, the New Orleans Saints (+13.1%), Pittsburgh Steelers (+12.4%) and Ravens (12.1%) are the closest challengers to the Patriots.

2020New Orleans Saints27.6%
2019Baltimore Ravens30.4%
2018Chicago Bears24.4%
2017Jacksonville Jaguars26.6%
2016New England Patriots20.0%
2015Seattle Seahawks31.4%
2014Seattle Seahawks20.2%
2013Denver Broncos24.5%
2012Denver Broncos26.1%
2011New Orleans Saints28.4%
2010San Diego Chargers26.3%
2009Green Bay Packers29.1%
2008Baltimore Ravens26.7%
2007New England Patriots42.2%
2006San Diego Chargers26.2%
Team Efficiency Rankings – Lowest Ratings 2006-2020

As we know, for every action, there’s a reaction, and these rankings are no different.

We have seen some truly awful NFL teams over the past 15 years, but the worst I’ve graded was the 2009 Detroit Lions, who finished the season with a -40.5% season rating. Though truly terrible, the 2009 Lions actually graded worse than they had the previous season when they were the first NFL team ever to go 0-16 in the regular season, finishing with a -40.2% grade. When you consider that last season’s worst team, the New York Jets, only graded at -33.1%, you can see that the 2009 Lions were truly something special (in a bad way).

The other 0-16 team we’ve seen in NFL history, the 2017 Cleveland Browns, finished with a fairly respectable season rating of -21.2% that was good enough to finish 29th in the 2017  rankings, showing that the record did not completely reflect the performances of the team in that season.

The lowest average rated team in the last 15 years has been the Cleveland Browns, with an average rating of -14.4%, with the Lions (-12.9%), Oakland/Las Vegas Raiders (-12.2%) and Jacksonville Jaguars (-9.7%) the closest ranked teams at the bottom of the rankings.

2020New York Jets-33.1%
2019Miami Dolphins-33.4%
2018Arizona Cardinals-35.9%
2017New York Giants-26.4%
2016Cleveland Browns-29.2%
2015San Francisco 49ers-26.8%
2014Jacksonville Jaguars-26.6%
2013Jacksonville Jaguars-30.4%
2012Jacksonville Jaguars-29.2%
2011St Louis Rams-33.1%
2010Carolina Panthers-31.4%
2009Detroit Lions-40.5%
2008Detroit Lions-40.2%
2007San Francisco 49ers-27.2%
2006Tampa Bay Buccaneers-21.4%
Offensive NEFF (ONEFF) Rankings

There is a trend appearing in the offensive NEFF ratings where we are seeing a gradual increase in the average offensive rating every year since 2010, with only 2019 seeing a slight dip in this upward curve. 2020 finished with an average offensive rating of +42.5%, which was 12.5% higher than the 2010 mark and was possibly reflective of the unusual circumstances surrounding last season and the impacts of COVID-19.

In terms of the top-rated offenses I’ve grades, last season saw a new best ever thanks to the Green Bay Packers finishing the 2020 season with a +66.7% rating, led by league MVP Aaron Rodgers. This beat the previous best, the historic 2007 Patriots who had recorded a +60.5% rating in their perfect regular season.

Top Rated ONEFF 2006-2020
2020Green Bay Packers66.7%
2007New England Patriots60.5%
2018Kansas City Chiefs57.5%
2019Baltimore Ravens56.8%
2020New Orleans Saints56.3%
2006San Diego Chargers55.6%
2020Kansas City Chiefs55.5%
2020Tennessee Titans55.5%
2018New Orleans Saints55.2%
2011New Orleans Saints55.0%
Defensive NEFF (DNEFF) Rankings

As we have seen the ONEFF ratings rise over the past few years, naturally we have seen the opposite from a DNEFF perspective, with the 2020 average rating of -43.7% some 13.5% lower than the best season in 2010.

The top rated defense I’ve graded was the 2010 Steelers, who finished the season with a -16.1% rating. That Steelers team allowed just 20 defensive touchdowns all season and under 4,500 total yards. Since 2010, the only team that came close to the Steelers was the now legendary 2013 Seahawks who posted a -16.8% rating on their way to winning the Super Bowl.

Top Rated DNEFF 2006-2020
2010Pittsburgh Steelers-16.1%
2013Seattle Seahawks-16.8%
2009New York Jets-17.0%
2008Baltimore Ravens-17.3%
2008Pittsburgh Steelers-18.2%
2011Baltimore Ravens-18.6%
2019New England Patriots-19.5%
2013Carolina Panthers-19.5%
2015New York Jets-19.8%
2011San Francisco 49ers-20.0%
Special Teams NEFF (STNEFF) Rankings

The special teams NEFF ratings and rankings cover off all forms of special teams play (kickoffs, punting and place kicking) and though they only contribute a small amount to the overall team ranking, are an important aspect to properly analyze and grade. Because of the multiple and very different facets to special teams play, the STNEFF ratings tend to perform closer to zero than for offense and defense. This also means that because the likelihood of all three special teams phases being perfect in a given game are pretty low, it means I’ve never had a perfect special teams rating in the near 4,000 games I’ve graded.

Top Rated STNEFF 2006-2020
2017Los Angeles Rams29.9%
2017Kansas City Chiefs26.3%
2019Carolina Panthers25.0%
2020Carolina Panthers21.1%
2014Minnesota Vikings20.6%
2018Chicago Bears18.8%
2016Philadelphia Eagles18.0%
2015Baltimore Ravens17.7%
2011New Orleans Saints17.4%
2013San Francisco 49ers17.0%