Football Outsiders Basics (a.k.a. "Pregame Show")

by Aaron Schatz

While reading Football Outsiders or the Football Outsiders Almanac, new readers will often come across an offhand comment about, for example, the idea that fumble recovery is not a skill, and wonder what in the heck we are talking about. In each edition of Football Outsiders Almanac, we now include an essay called "Pregame Show" which gives a basic look at some of the most important precepts that have emerged during nine years of Football Outsiders research. That essay is republished here, along with links to the original research online when possible, or mentions of where that research appeared in print.

Please note that some of our basic research findings, such as the split between offense, defense, and special teams, were never addressed in one specific article, but instead developed over time. Therefore, there is no specific article we can point out.

This essay was last updated in June 2022.

You run when you win, not win when you run.

The first article ever written for Football Outsiders was devoted to debunking the myth of "establishing the run." There is no correlation whatsoever between giving your running backs a lot of carries early in the game and winning the game. Just running the ball is not going to help a team score; it has to run successfully.

There are two reasons why nearly every beat writer and television analyst still repeats the tired old-school mantra that "establishing the run" is the secret to winning football games. The first problem is confusing cause and effect. There are exceptions, but for the most part, winning teams have a lot of carries because their running backs are running out the clock at the end of wins, not because they are running wild early in games.

The second problem is history. Most of the current crop of NFL analysts came of age or actually played the game during the 1970s. They believe that the run-heavy game of that decade is how football is meant to be, and today's pass-first game is an aberration. As we addressed in an essay in Pro Football Prospectus 2007 about the history of NFL stats, it was actually the game of the 1970s that was the aberration. The '70s were far more slanted towards the run than any era since the arrival of Paul Brown, Otto Graham, and the Cleveland Browns in 1946.

We used to have to explain that optimal strategies from 1974 are not optimal strategies for today. But this would seem to be a smaller problem now than it was ten years ago; most current NFL analysts played the game in the 1990s or beyond, when the game was heavily pass-centric.

Another issue may be a confusion of professional football with other levels. As you go down the football pyramid, from NFL teams to FBS to FCS to Division II and so on, all the way down to high school, at every level further down the running game becomes more important. Strategies that win on Saturday do not necessarily win on Sunday.

A sister statement to "you have to establish the run" is "team X is 5-1 when running back John Doe runs for at least 100 yards." Unless John Doe is ripping off six-yard gains Jamaal Charles-style, the team isn't winning because of his 100-yard games. He's putting up 100-yard games because his team is winning.

A great defense against the run is nothing without a good pass defense.

This is a corollary to the absurdity of “establish the run.” With rare exceptions, teams win or lose with the passing game more than the running game—and by stopping the passing game more than the running game. Ron Jaworski puts it best: “The pass gives you the lead, and the run solidifies it.” The reason why teams need a strong run defense in the playoffs is not to shut the run down early; it’s to keep the other team from icing the clock if they get a lead. You can’t mount a comeback if you can’t stop the run.

Note that "good pass defense" may mean "good pass rush" rather than "good defensive backs."

Running on third-and-short is more likely to convert than passing on third-and-short.

On average, passing will always gain more yardage than running, with one very important exception: when a team is just one or two yards away from a new set of downs or the goal line. On third-and-1, a run will convert for a new set of downs 36% more often than a pass. Expand that to all third or fourth downs with 1-2 yards to go, and the run is successful 40% more often. With these percentages, the possibility of a long gain with a pass is not worth the tradeoff of an incomplete that kills a drive.

This is one reason why teams have to be able to both run and pass. The offense also has to keep some semblance of balance so they can use their play-action fakes—you can't run a play-fake from an empty set—and so the defense doesn’t just run their nickel and dime packages all game. Balance also means that teams do need to pass occasionally in short-yardage situations; they just need to do it less than they do now. Teams pass roughly 60% of the time on third-and-2 even though runs in that situation convert 20% more often than passes. They pass 68% of the time on fourth-and-2 even though runs in that situation convert twice as often as passes.

You don't need to run a lot to set up play-action.

Of course, the idea that you have to run a little bit so play-action will work doesn't mean you have to run as often as NFL teams currently do. There's no correlation between a team's rushing frequency or success rate rushing and its play-action effectiveness over the course of either a single game or an entire season. That doesn't mean there wouldn't be a correlation at an extreme run/pass ratio, but we have yet to see an NFL team that even comes close to what that extreme might be.

Standard team rankings based on total yardage are inherently flawed.

Check out the schedule page on NFL.com, and you will find that each game is listed with league rankings based on total yardage. That is still how the NFL “officially” ranks teams, but these rankings rarely match up with common sense. That is because total team yardage may be the most context-dependent number in football.

It starts with the basic concept that rate stats are generally more valuable than cumulative stats. Yards per carry says more about a running back’s quality than total yardage, completion percentage says more than just a quarterback’s total number of completions. The same thing is true for teams; in fact, it is even more important because of the way football strategy influences the number of runs and passes in the game plan. Poor teams will give up fewer passing yards and more rushing yards because opponents will stop passing once they have a late-game lead and will run out the clock instead. For winning teams, the opposite is true. For example, which team had a better pass defense in 2021: Jacksonville or Tampa Bay? According to the official NFL rankings, Jacksonville (3,875 yards allowed on 575 passes and sacks, 6.7 net yards per pass) was a better pass defense than Tampa Bay (4,062 yards allowed on 727 passes and sacks, 5.6 net yards per pass.)

Total yardage rankings are also skewed because some teams play at a faster pace than other teams. For example, in 2021 Baltimore (6,440) had more yardage than Green Bay (6.215). However, the Packers were the superior offense and much more efficient; they gained those yards on only 162 drives while the Ravens needed 190 drives.

  • Pro Football Prospectus 2005, Cleveland chapter
  • Pro Football Prospectus 2005, New York Jets chapter

A team will score more when playing a bad defense, and will give up more points when playing a good offense.

This sounds absurdly basic, but when people consider team and player stats without looking at strength of schedule, they are ignoring this. In 2007, Tony Romo and Derek Anderson had similar numbers, but Romo faced a much tougher schedule than Anderson did. Romo was better that year, and better in the long run.

In 2014, Le'Veon Bell played 12 games that finished in the bottom half of the league in run defense DVOA. He averaged 96.8 yards per game and 4.9 yards per carry in those contests. In his four outings against upper-half run defenses, those averages fell to 49.8 yards per game and 3.8 yards per carry.

Because players and teams don't give the exact same performance every week, this is more of a general law, and it doesn't necessarily apply in the short term.

  • Pro Football Prospectus 2005, Cincinnati chapter

If their overall yards per carry are equal, a running back who consistently gains yardage on every play is more valuable than a boom-and-bust running back who is frequently stuffed at the line but occasionally breaks a long highlight-worthy run.

Our brethren at Baseball Prospectus believe that the most precious commodity in baseball is outs. Teams only get 27 of them per game, and you can't afford to give one up for very little return. So imagine if there was a new rule in baseball that gave a team a way to earn another three outs in the middle of the inning. That would be pretty useful, right?

That's the way football works. You may start a drive 80 yards away from scoring, but as long as you can earn 10 yards in four chances, you get another four chances. Long gains have plenty of value, but if those long gains are mixed with a lot of short gains, you are going to put the quarterback in a lot of difficult third-and-long situations. That means more punts and more giving the ball back to the other team rather than moving the chains and giving the offense four more plays to work with.

The running back who gains consistent yardage is also going to do a lot more for you late in the game, when the goal of running the ball is not just to gain yardage but to eat clock time. If you are a Baltimore Ravens fan watching your team with a late lead, you don't want to see three straight Justin Forsett stuffs at the line followed by a punt. You want to see a game-icing first down.

A common historical misconception is that our preference for consistent running backs means that "Football Outsiders believes that Barry Sanders was overrated." Sanders wasn't just any boom-and-bust running back, though; he was the greatest boom-and-bust runner of all time, with bigger booms and fewer busts. Our play-by-play database goes back to 1989, the first year of Sanders' career. Sanders finished in the top five of rushing DYAR in 1989, 1990, 1991, 1994, 1996, and 1997.

Rushing is more dependent on the offensive line than people realize, but pass protection is more dependent on the quarterback himself than people realize.

Some readers complain that this idea contradicts the previous one. Aren’t those consistent running backs just the product of good offensive lines? The truth is somewhere in between. There are certainly good running backs who suffer because their offensive lines cannot create consistent holes, but most boom-and-bust running backs contribute to their own problems by hesitating behind the line whenever the hole is unclear, looking for the home run instead of charging forward for the four-yard gain that keeps the offense moving.

Further research has shown that rushing success is also heavily dependent on scheme as well as how the defense sets up against the play, in particular how many men the defense puts in the box (i.e. in between the offensive tackles). Research from 2019's NFL Big Data Bowl suggests that the results of a running play can be almost entirely predicted using the movement of the blockers and defenders, without needing to consider the identity of the running back at all. It's research like this that's given birth to the popular Twitter saying that "running backs don't matter." That's a bit of an extreme; it's more likely that running backs matter a little bit, but much less than NFL wisdom has historically believed, and most of the differentiation between different backs comes from their skills in the passing game.

In addition, "running backs don't matter" is sometimes mistaken for the idea that the running game doesn't matter. The latter is a bit of an analytical strawman, even if analytics has shown that the running game is less important than the passing game.

As for pass protection, some quarterbacks have better instincts for the rush than others and are thus better at getting out of trouble by moving around in the pocket or throwing the ball away. Others will hesitate, hold onto the ball too long, and lose yardage over and over. Sack rates and pressure rates have strong correlation from year-to-year even when a quarterback changes teams in between seasons.

Note that “moving around in the pocket” does not necessarily mean “scrambling.” In fact, a scrambling quarterback will often take more sacks than a pocket quarterback, because while he’s running around trying to make something happen, a defensive lineman will catch up with him.

Shotgun formations are generally more efficient than formations with the quarterback under center.

From 2013 to 2017, offenses averaged roughly 5.9 yards per play from shotgun (or pistol), but just 5.1 yards per play with the quarterback under center. Since 2018 that gap has closed a bit, but offenses still averaged 5.8 yards per play from shotgun or pistol over the last two seasons compared to 5.2 yards per play with the quarterback under center. This wide split exists even if you analyze the data to try to weed out biases like teams using shotgun more often on third-and-long, or against prevent defenses in the fourth quarter. Shotgun offense is more efficient if you only look at the first half, on every down, and even if you only look at running back carries rather than passes and scrambles.

It's hard to think of a Football Outsiders axiom that has been better assimilated by the people running NFL teams since we started doing this a decade ago. In 2001, NFL teams only used shotgun on 14% of plays. Five years later, in 2006, that had increased slightly, to 20% of plays. By 2012, shotgun was used on a 47.5% of plays (including the pistol, but not counting the Wildcat or other direct snaps to non-quarterbacks). In 2016, the league as a whole was up to an average of 64.4% of plays from shotgun or pistol. In 2021, that average was at 66.4%.

There's an interesting corollary here which we are just starting to study, because there does seem to be one split where offenses are less efficient from shotgun: play-action. In 2021, for example, offenses averaged 7.2 yards per play when using play-action from under center compared to 6.7 yards per play when using play-action from a shotgun formation (not including penalties). A number of teams that are near the top of the league in play-action usage, such as the 49ers and Titans, are also near the bottom of the league in using shotgun . That said, the rise of the run-pass option also means that there are also a number of teams that are near the top of the league in both play-action and shotgun, such as the Dolphins and Cardinals.

  • Pro Football Prospectus 2007, Tampa Bay chapter

A running back with 370 or more carries during the regular season will usually suffer either a major injury or a loss of effectiveness the following year, unless he is named Eric Dickerson.

Terrell Davis, Jamal Anderson, and Edgerrin James all blew out their knees. Larry Johnson broke his foot. Earl Campbell and Eddie George went from legendary powerhouses to plodding, replacement-level players. Shaun Alexander broke his foot and became a plodding, replacement-level player. This is what happens when a running back is overworked to the point of having at least 370 carries during the regular season.

The "Curse of 370" was expanded in Pro Football Prospectus 2006 to include seasons with 390 or more carries in the regular season and postseason combined. Research also shows that receptions don't cause a problem, only workload on the ground.

Plenty of running backs get injured without hitting 370 carries in a season, but there is a clear difference. On average, running backs with 300 to 369 carries and no postseason appearance will see their total rushing yardage decline by 15 percent the following year and their yards per carry decline by two percent. The average running back with 370 or more regular-season carries, or 390 including the postseason, will see their rushing yardage decline by 35 percent, and their yards per carry decline by eight percent. However, the Curse of 370 is not a hard and fast line where running backs suddenly become injury risks. It is more of a concept where 370 carries is roughly the point at which additional carries start to become more and more of a problem.

Research in Pro Football Prospectus 2008 suggests that overuse in college does not create a problem for top prospects, but also shows that players chosen after the first round rarely have a successful NFL career after a college season with over 330 carries.

It’s worth noting that the return to the committee backfields that dominated the '60s and '70s have mostly meant an end to the Curse of 370. No running back had gone over 370 carries since Michael Turner in 2008 until DeMarco Murray ran the ball 392 times in 2014. The Cowboys, perhaps fearing for Murray's health, allowed him to enter unrestricted free agency.

Wide receivers and tight ends must be judged on both complete and incomplete passes.

Here's an example from 2021: Kyle Pitts had 1,026 receiving yards while Robby Anderson had just 519 receiving yards, even though the two receivers had the same number of targets. Each player ran his average route roughly 10.5 yards downfield. Each player was in a generally below-average offense. But there was a big reason why Pitts had a much better season than Anderson: Pitts caught 62% of intended passes and Anderson caught just 48%.

We don't yet know enough to precisely parse the blame for incomplete passes, but we know that wide receiver catch rates are as consistent from year to year as quarterback completion percentages. However, it is also important to look at catch rate in the context of the types of routes each receiver runs. We recently expanded on this idea with a new plus/minus metric.

The total quality of an NFL team is four parts offense, three parts defense, and one part special teams.

There are three units on a football team, but they are not of equal importance. Our DVOA ratings provide good evidence for this. For a long time, the saying from Football Outsiders was that the total quality of an NFL team is three parts offense, three parts defense, and one part special teams. Further recent research suggests that offense is even more important than we originally believed. Recent work by Chase Stuart, Neil Paine, and Brian Burke suggests a split between offense and defense of roughly 58-42, without considering special teams. Our research suggests that special teams contributes about 13 percent to total performance; if you measure the remaining 87 percent with a 58-42 ratio, you get roughly 4:3:1. When we compare the range of offense, defense, and special teams DVOA ratings, we get the same results, with the best and worst offenses roughly 130 percent stronger than the best and worst defenses, and roughly four times stronger than the best and worst special teams.

Offense is more consistent from year to year than defense, and offensive performance is easier to project than defensive performance. Special teams is less consistent than either.

Nobody in the NFL understands this concept better than Indianapolis Colts general manager Bill Polian. Both the Super Bowl champion Colts and the four-time AFC champion Buffalo Bills of the early 1990s were built around the idea that if you put together an offense that can dominate the league year after year, eventually you will luck into a year where good health and a few smart decisions will give you a defense good enough to win a championship. (As the Colts learned in January 2007, you don't even need a year, just four weeks.) Even the New England Patriots, who are led by a defense-first head coach in Bill Belichick, have been more consistent on offense than on defense since they began their run of success in 2001.

Field-goal percentage is almost entirely random from season to season, while kickoff distance is one of the most consistent statistics in football.

This theory, which originally appeared in the New York Times in October 2006, is one of our most controversial, but it is hard to argue against the evidence. Measuring every kicker from 2012 to 2018 who had at least ten field goal attempts in each of two consecutive years, the year-to-year correlation coefficient for field goal percentage was an insignificant .06. Jason Myers of Seattle is a great example. He was below 80% in both 2016 and 2017. In 2018, he had a Pro Bowl season and connected on 92% of field goals, which got him a big contract in Seattle. In 2019, he declined to just 82%. In 2020, he rebounded and hit all 24 of his field goal attempts with no misses. And then in 2021, he was back down to 74% including two misses from inside 40 yards.

On the other hand, the year-to-year correlation coefficient for touchback percentage from 2012 to 2018, with a minimum of 10 kickoffs in each of two consecutive years, was .62. The same players consistently lead the league in kickoff distance. In recent years, that group includes Justin Tucker, Jake Elliott, and Harrison Butker.

Teams with more offensive penalties generally lose more games, but there is no correlation between defensive penalties and losses.

Specific defensive penalties of course lose games; we’ve all sworn at the television when the cornerback on our favorite team gets flagged for a 50-yard pass interference penalty. Yet overall, there is no correlation between losses and the total of defensive penalties or even the total yardage on defensive penalties. One reason is that defensive penalties often represent good play, not bad. Cornerbacks who play tight coverage may be just on the edge of a penalty on most plays, only occasionally earning a flag. Defensive ends who get a good jump on rushing the passer will gladly trade an encroachment penalty or two for ten snaps where they get off the blocks a split-second before the linemen trying to block them.

In addition, offensive penalties have a higher correlation from year to year than defensive penalties. The penalty that correlates highest with losses is the false start, and the penalty that teams will have called most consistently from year to year is also the false start.

  • Pro Football Prospectus 2007, St. Louis chapter

Recovery of a fumble, despite being the product of hard work, is almost entirely random.

Stripping the ball is a skill. Holding onto the ball is a skill. Pouncing on the ball as it is bouncing all over the place is not a skill. There is no correlation whatsoever between the percentage of fumbles recovered by a team in one year and the percentage they recover in the next year. The odds of recovery are based solely on the type of play involved, not the teams or any of their players.

Fans like to insist that specific coaches can teach their teams to recover more fumbles by swarming to the ball. Chicago's Lovie Smith, in particular, is supposed to have this ability. However, in Smith’s first three seasons as head coach of the Bears, their rate of fumble recovery on defense went from a league-best 76 percent in 2004 to a league-worst 33 percent in 2005, then back to 67 percent in 2006.

Fumble recovery is equally erratic on offense. In 2020, the Dallas Cowboys recovered only 4 of 17 fumbles on offense (24%), the lowest rate in the league. In 2021, the Cowboys recovered 15 of 23 fumbles on offense (65%) instead.

Fumble recovery is a major reason why the general public overestimates or underestimates certain teams. Fumbles are huge, turning-point plays that dramatically impact wins and losses in the past, while fumble recovery percentage says absolutely nothing about a team's chances of winning games in the future. With this in mind, Football Outsiders stats treat all fumbles as equal, penalizing them based on the likelihood of each type of fumble (run, pass, sack, etc.) being recovered by the defense.

Other plays that qualify as "non-predictive events" include blocked kicks and touchdowns during turnover returns. These plays are not "lucky," per se, but they have no value whatsoever for predicting future performance.

  • Pro Football Prospectus 2005, New Orleans chapter

Field position is fluid.

Every yard line on the field has a value based on how likely a team is to score from that location on the field as opposed to from a yard further back. The change in value from one yard to the next is the same whether the team has the ball or not. The goal of a defense is not just to prevent scoring, but to hold the opposition so that the offense can get the ball back in the best possible field position. A bad offense will score as many points as a good offense if it starts each drive five yards closer to the goal line.

A corollary to this precept: The most underrated aspect of an NFL team's performance is the field position gained or lost on kickoffs and punts. This is part of why players like Devin Hester and Cordarrelle Patterson can have such an impact on the game, even when they aren't taking a kickoff or punt all the way back for a touchdown.

The red zone is the most important place on the field to play well, but performance in the red zone from year to year is much less consistent than overall performance.

Although play in the red zone has a disproportionately high importance to the outcome of games relative to plays on the rest of the field, NFL teams do not exhibit a level of performance in the red zone that is consistently better or worse than their performance elsewhere, year after year. The simplest explanation why is a small(er) sample size and the inherent variance of football, with contributing factors like injuries and changes in personnel.

  • Football Outsiders Almanac 2009, "The Red Menace"

Injuries regress to the mean on the seasonal level, and teams that avoid injuries in a given season tend to win more games.

There are no doubt teams with streaks of good or bad health over multiple years. However, teams who were especially healthy or especially unhealthy, as measured by our Adjusted Games Lost (AGL) metric, almost always head towards league average in the subsequent season. Furthermore, injury -- or the absence thereof -- has a huge correlation with wins, and a significant impact on a team's success. There's no doubt that a few high-profile teams have resisted this trend in recent years. The Patriots often deal with a high number of injuries, and the 2017 Eagles obviously overcame a number of important injuries to win the championship. In 2021, Super Bowl opponents Los Angeles and Cincinnati both ranked among the top eight teams for fewest AGL. Ten of 14 playoff teams finished in the top half of the league. Meanwhile, out of the 10 teams with the highest overall AGL, only San Francisco made the playoffs.

Teams with a high number of injuries are a good bet to improve the following season. However, while injury totals tend to regress towards the mean, there's also no doubt that certain teams have a record of staying healthier than others.

  • Pro Football Prospectus 2008, "The Injury Effect"

By and large, a team built on depth is better than a team built on stars and scrubs.

Connected to the previous statement, because teams need to go into the season expecting that they will suffer an average number of injuries no matter how healthy they were the previous year. The Redskins went into 2006 with a Super Bowl-quality starting lineup, and finished 5-11 because they had no depth. You cannot concentrate your salaries on a handful of star players because there is no such thing as avoiding injuries in the NFL. Every team will suffer injuries; the only question is how many. The game is too fast and the players too strong to build a team based around the idea that "if we can avoid all injuries this year, we'll win."

Running backs usually decline after age 28, tight ends after age 29, wide receivers after age 30, and quarterbacks after age 32.

This research was originally done by Doug Drinen (editor of Pro-Football-Reference.com). In recent years, a few players have had huge seasons above these general age limits (most notably Tiki Barber, Tony Gonzalez, and Terrell Owens), but the peak ages Drinen found a few years ago still apply to the majority of players.

During the summer of 2007, ESPN The Magazine asked us to research when players decline at "non-skill" positions. This research was not as rigorous as our usual work, and needs a little more attention before we're ready to stand by it. For the curious, however, the preliminary results said that defensive ends and defensive backs generally begin to decline after age 29, linebackers and offensive linemen after age 30, and defensive tackles after age 31.

The future NFL success of quarterbacks can be projected with a high degree of accuracy by analyzing their collegiate performance, starting experience, and projected draft slot.

QBASE, our latest attempt to project the NFL careers of draft-eligible quarterbacks, was developed by Andrew Healy and unveiled in April of 2015. The math behind QBASE is complex, but the idea is simple: quarterbacks who played well in college over a large sample size and also impressed scouts with their intangible qualities are more likely to succeed in the pro ranks than their peers. The trick is identifying prospects who meet all three criteria.

From 1997 to 2010, the top QBASE scores for quarterbacks taken in the first 100 picks of the draft belonged to Philip Rivers, Carson Palmer, Donovan McNabb, Peyton Manning, Byron Leftwich, Aaron Rodgers, Ben Roethlisberger, John Beck, Matthew Stafford, Chad Pennington, and Daunte Culpepper. With the obvious exceptions of Leftwich and Beck (hey, nobody's perfect), each of those quarterbacks started for at least five years in the NFL and led his team(s) to multiple playoff berths.

At the other extreme, the worst QBASE scores among highly drafted quarterbacks in that timeframe belonged to Josh McCown, Trent Edwards, Charlie Batch, Kevin O'Connell, Michael Vick, Charlie Whitehurst, Marques Tuiasosopo, Chris Simms, Patrick Ramsey, and Brodie Croyle. None of those players ever developed into a consistently efficient passer.

Prior to 2015, we evaluated collegiate quarterback prospects using the Lewin Career Forecast, named after its creator David Lewin and later re-named the Long-term Career Forecast. It was a simpler system that used completion percentage and games started in college to project each prospect's career in the NFL. We've left the links here if you'd like to explore how our methodology has evolved over time.

Highly-drafted wide receivers without many college touchdowns are likely to bust.

Football Outsiders Almanac 2009 introduced a new metric called Playmaker Score, which measures rookie wide receivers by simply multiplying average yards per reception and total career touchdowns in college. Players who score high in this metric do not necessarily become stars in the NFL, but no first- or second-round pick with a score below 8.0 has yet to live up to his draft position. Like the Lewin Career Forecast, Playmaker Score is far more accurate with receivers chosen in the first two rounds, and it doesn't seem to work for hybrid slot receiver/running backs such as Percy Harvin and Dexter McCluster.

  • Football Outsiders Almanac 2009, "Introducing Playmaker Score"

The strongest indicator of how a college football team will perform in the upcoming season is their performance in recent seasons.

It may seem strange because graduation enforces constant player turnover, but college football teams are actually much more consistent from year to year than NFL teams. Thanks in large part to consistency in recruiting, teams can be expected to play within a reasonable range of their baseline program expectations each season. Our Program F/+ ratings, which represent a rolling five-year period of play-by-play and drive efficiency data, have an extremely strong (.76) correlation with the next year’s F/+ rating.

Championship teams are generally defined by their ability to dominate inferior opponents, not their ability to win close games.

Football games are often decided by just one or two plays -- a missed field goal, a bouncing fumble, the subjective spot of an official on fourth-and-1. One missed assignment by a cornerback, or one slightly askew pass that bounces off a receiver's hands and into those of a defensive back five yards away and the game could be over. In a blowout, however, one lucky bounce isn't going to change things.

Championship teams beat their good opponents convincingly and destroy the cupcakes on the schedule. Certainly there are exceptions to this rule, including last year's Super Bowl champion. However, in the DVOA era (1989-2014), 23 of 26 Super Bowl champions have had more blowouts against sub-.500 teams than close wins against above-.500 teams.

For more on Football Outsiders, see the introduction to our statistical methods as well as the Football Outsiders FAQ.