AGL 2022: Injuries Help Lead to Broncos Trainwreck

NFL Offseason - Usually, a trainwreck leads to injuries. In the NFL, however, injuries help lead to a trainwreck. That was certainly the case in Denver this season, as the Broncos led the NFL in Football Outsiders' adjusted games lost metric which measures injuries to starters and important situational players.

No, injuries do not explain the decline and fall of Russell Wilson, and they don't mitigate the strange coaching decisions of Nathaniel Hackett. But a Denver team with average health might have finished the year 7-10 instead of 5-12. That's a disappointing season, but not a disaster.

The Broncos finished with 148.6 AGL, narrowly surpassing the Los Angeles Rams at 146.6 AGL. Tennessee ranked third, with a significant gap between the Broncos and Rams and the rest of the league.

(Ed. Note: Further review of this year's injuries after this article was originally posted found that we had missed a number of "new starter" injuries for the Los Angeles Rams offensive line and the Cleveland linebackers. Numbers here now reflect this updated data which increases AGL for the Rams and Browns in 2022. We'll discuss these numbers further in Part II of our AGL report next week.)

A quick look at the teams with the most and fewest AGL shows the importance of injuries in determining which teams are going to be successful and make the postseason. Of the 10 teams with the most AGL, three teams made the postseason. That includes the Tampa Bay Buccaneers, who won their division with a losing record, along with the New York Giants and San Francisco 49ers, further emphasizing the strong coaching performance of Brian Daboll and Kyle Shanahan.

The Pittsburgh Steelers finished with a league-low 32.0 AGL and missed the playoffs, but the next four teams with the fewest AGL did make it to the postseason. Jacksonville was second, the Super Bowl teams Philadelphia and Kansas City were third and fourth, and Minnesota was fifth. Seattle and Cincinnati also made the playoffs while finishing among the 10 teams with the least amount of AGL.

For over a decade, Football Outsiders has collected data from the NFL's weekly injury reports and transformed it into adjusted games lost. We also have the data going backwards, covering the entire 21st century. Adjusted games lost doesn't just add up total injuries. It accounts for both absent players and those playing at less than 100%, and it gives more weight to injuries to expected starters and situational players than to expected backups. As such, AGL estimates the impact of injuries on teams and provides a comparable total that often succinctly explains why teams improved or declined from one year to the next. 

Total AGL for the entire league was down slightly in 2022 (2.3%) when compared to 2021 numbers that do not include COVID absences. AGL per 16 games was higher than 2020, lower than 2019, and about the same as 2018. Overall, it looks like injury totals in the NFL are fairly stable over the last few years after gradually rising during the period from 2006 to 2016.

Team Results

While Denver had the most AGL in the league this year, the Broncos did not have a historical number of AGL. The Broncos were far below last year's record-setting Baltimore total of 191.2 AGL, and they finished below the top AGL teams from both 2019 and 2020 even though those seasons had only 16 games apiece.

Denver's annus horribilis kicked off when wide receiver Tim Patrick tore up his knee in training camp, and wide receiver is where the Broncos had the most AGL. KJ Hamler also missed half the season while Jerry Jeudy, Courtland Sutton, and Kendall Hinton all missed games. On the offensive line, the Broncos went without left tackle Garett Bolles for two-thirds of the season and center Lloyd Cushenberry for half, while Quinn Meinerz missed four games and Dalton Risner fought injuries all over his body all season despite starting 15 games. On defense, the biggest problems came at defensive back, as Ronald Darby was gone after Week 5, Justin Simmons missed time in September and October, and K'Waun Williams was on the injury report with elbow and wrist issues all season.

Here we go with the numbers. Hopefully this isn't confusing, but ranks go from best (fewest injuries) to worst (most injuries).

Note that the AGL numbers for Buffalo and Cincinnati include the cancelled Week 17 game, based on the injury report that week and who was on injured reserve at the time.

The Los Angeles Rams had the biggest rise in injuries over 2021, playing a major role in the team's fall from Super Bowl champions to a spot near the bottom of the league. The Rams' offensive line was decimated by injuries last season, but they also had a lot of AGL from defensive backs and wide receivers. Even at quarterback, the Rams not only lost starter Matthew Stafford but also backup John Wolford.

The Baltimore Ravens had the biggest drop in injures compared to 2021, but still finished 25th in AGL because they set an all-time record for AGL two years ago.

Does it seem like the same teams finish high (or low) in AGL every year? Your eyes do not decieve you. Despite what we've seen from the Ravens over the last two years, this hasn't been a longstanding problem for Baltimore. In the three previous years, Baltimore had finished first (2018), 16th (2019), and eighth (2020 without COVID) in AGL. However, other teams show more consistency:

• Denver has ranked in the bottom 10 for AGL for four straight seasons.
• Arizona has ranked below 20th in AGL for seven straight seasons.
• Washington has ranked below 20th in AGL for nine straight seasons.
• San Francisco has ranked below 20th in AGL for a remarkable 10 straight seasons.

On the other hand...

• Atlanta has ranked in the top dozen for AGL in seven of the last eight seasons.
• Buffalo has been above average in AGL for six straight seasons.
• Pittsburgh has been in the top 10 for AGL in six of the last seven seasons.
• The Los Angeles Rams had been in the top 10 for AGL for six straight seasons until they crashed in 2022.

We want to believe that injuries are entirely random, but there's evidence here that they are not. Certainly, numbers at the extremes are going to regress towards the mean from year to year. It's very, very unlikely that the Broncos will be decimated by injury again in 2023 the way they were in 2022. Teams such as Jacksonville and Pittsburgh (especially on offense, as you'll see below) are going to have more injuries in the upcoming season. However, there is real consistency in AGL totals. If we take out players who missed games due to COVID, the year-to-year correlation coefficient for AGL in 2021 and 2022 was .35. For the last decade, removing COVID games in both 2020 and 2021, the year-to-year correlation for AGL has been .28.

The next question is why there seems to be year-to-year correlation for AGL. It's a important question for NFL teams to answer, but I'm not quite sure how to answer it. Does it have to do with the turf in certain stadiums? Are certain players just more injury prone and certain teams more willing to overlook that weakness when compiling their rosters? Is the problem with specific training staffs and how they do their jobs? The NFL PA may have tried to answer that last question recently...

(Brief aside: It's worth noting that AGL had much less year-to-year correlation in the first few years for which we have it compiled, in particular from 2002 to 2008. Whether this is because of a change in how we've marked players for the purposes of counting AGL or an actual change regarding injuries in the NFL, I can't answer.)

AGL vs. NFLPA Grades

This year, for the first time, the NFL Players Association released report cards grading teams on their working conditions. Many of the categories could have ramifications for adjusted games lost, but two of them stood out in particular: training staff and training rooms.

The grades for training staffs aren't going to do us much good, unfortunately. Only three teams in the league received less than a B+: Kansas City at D-, Washington at D, and the Los Angeles Chargers at C-. Obviously, it's interesting to have Washington graded so low because we know that the Commanders have a lot of AGL every year. The Chiefs and Chargers were not particularly high in AGL over the last two seasons. However, the specifics on that Kansas City grade give us something to watch going forward when it comes to how often Chiefs players are listed on the injury report. Chiefs players were very negative about head trainer Rick Burkholder and expressed that they are discouraged from reporting injuries and fear retribution for speaking up for better care. Could this be part of the reason why the Chiefs were so low in AGL over the last couple seasons?

There is a much wider distribution in the grades for training rooms, with everything from three teams at A+ to three teams at F-. (The report cards had very few just plain Fs, which is weird.) A looked at the correlation between these grades and AGL by converting the grades to a GPA using the typical scale (A = 4, B = 3, F = 0, a little higher or lower for +/-, etc.). And what I discovered was... nothing. The correlation between training room grade and 2022 AGL was -0.004. Then I looked at the correlation between training room grade and combined injuries for 2021-2022. That was slightly better at -0.05, meaning that a better grade meant slightly fewer injuries in 2021-2022, but still there's not much there. There are a lot of good reasons for NFL teams to concentrate resources on improving their grades in the NFLPA report cards, in particular in order to attract better free agents. Based on AGL, it doesn't look like improving these grades will improve the level of injuries each team struggles with during the season.

Offense vs. Defense

Looking at the split of offensive and defensive AGL shows some gigantic gaps between each side of the ball, in particular for the Buffalo Bills and New York Jets. 

Were you wondering how the New York Jets improved from dead last in defensive DVOA in 2021 to fifth in the league in 2022? Adding young talent such as Sauce Gardner certainly helped, as did getting some stars back from injury. It was good to have another year in Robert Saleh's system. But health played a huge role in the Jets defense playing so well last season, as no team had fewer AGL on that side of the ball. Safety Lamarcus Joyner was the only starter to miss more than two games, and he just missed three. However, the Jets were near the bottom of the league in offensive AGL. As you'll learn next week when we break things down by position, it's almost all offensive linemen (plus some Breece Hall).

The Buffalo Bills also had a huge split between offense and defense, but it went in the other direction. Mitch Morse was the only offensive starter to miss more than two games, and it has less impact on AGL because two of those weeks Morse was listed as questionable instead of out. No Bills offensive starter went on injured reserve. But on defense, the Bills ranked 31st in AGL primarily due to defensive back injuries. Tre'Davious White missed half the year coming back from his 2021 torn ACL, Micah Hyde was out almost the entire season, and Christian Benford missed significant time as well. Losing superstar edge rusher Von Miller for six games didn't help either.

The only team to lose more AGL on defense than Buffalo was Tennessee. The Titans lost significant time from starters at every defensive position except interior defensive line. Defensive back was a particularly big issue with Kristian Fulton, Amani Hooker, and Elijah Molden all strugging with major injuries. We didn't even count 2021 first-round pick Caleb Farley as an important situational player, but he also missed eight games in 2022.

Finally, we have to point out the very tiny offensive AGL put up by the Pittsburgh Steelers. Their starting lineup on offense missed two games all season. TWO! Kenny Pickett was inactive with a concussion in Week 15, and Pat Freiermuth was inactive with a concussion in Week 6. This is definitely one reason why the Steelers came out a suprising 18th in offensive DVOA despite a rookie quarterback. (Update: The Steelers actually had the lowest offensive AGL of any team since 2006, as pointed out in this comment below.)

Next week, we'll look at which teams struggled with the most AGL at each position in 2022.