Pro Football History.com Blog

By Wyatt Taylor and Stephen Juza

In our last piece, we discussed the increasing tendency of NFL teams to make in-season coordinator changes; this tendency has been entirely driven by a recent trend of changing offensive coordinators in the middle of the season. Today we’ll look at the ultimate outcomes of making such a change: team performance.

Once again, we examined all in-season coordinator changes since the 2008 season. The distinct majority of such coordinator changes happen in the middle of season, between weeks 5-11. These changes often happen heading into the team’s bye-week, likely in order to give the new coordinator as much time to prepare as possible. The timings of these in-season changes seem fairly straightforward: the beginning of the season has not gone as planned, and teams make a change at coordinator to attempt to save the season.

Perhaps surprisingly, though we noted teams’ increasingly itchy trigger fingers when it comes to replacing coordinators mid-season, the teams that have made a coordinator change have performed at a consistent (and poor) level. Better performing teams have not consistently made mid-season coordinator changes.

Not only are bad teams becoming more likely to move on from poor performing coordinators mid-season, but those changes have been consistently correct. The team ends the season with a higher winning percentage than it had when it changed coordinators. 17 out of 25 teams which made such a change ended the season with a better win percentage, going from an average 30% winning percentage to 37%. This equates to an extra win over the course of a season.

In our last piece, we noted that teams had become especially apt to change offensive coordinators over the past four seasons. The majority of these midseason offensive coordinator changes over the past four seasons (10 out of 16 occurrences, 63% correct) have yielded positive results for the team making the change. Even at an increased rate relative to the previous seven seasons, these decisions have continued to yield positive results.

From our past two examinations into midseason coordinator changes, we can draw several conclusions.

  1. Poorly performing teams are less likely to wait until the end of the season to make a coordinator change, especially on the offensive side of the ball.
  2. These changes often lend positive results for the team making the coordinator change, yielding increased end-of-year winning percentages.

We began this miniseries into coordinator changes with the example of the Jacksonville Jaguars, who fired offensive coordinator Nathaniel Hackett and benched unpopular starting Quarterback Blake Bortles at the same time. Our findings suggest that perhaps other underperforming teams should take note of this decision. Rather than remaining loyal to the status quo in hopes of the team turning around on its own, a shakeup in decision making may lead to positive results.

By Wyatt Taylor and Stephen Juza

The Jacksonville Jaguars fired their offensive coordinator Nathaniel Hackett earlier this week, promoting quarterbacks coach Scott Milanovich to Interim offensive coordinator in his place. This is a somewhat familiar trend for the Jaguars; now-former Coach Hackett started as the team’s quarterbacks coach in 2015 before being named interim offensive coordinator following the firing of Greg Olson during the 2016 season.

With the cycle of interim coordinators repeating in Jacksonville, we thought this a good time to examine the recent history of interim coordinators in the NFL. We find that the frequency of such in-season coordinator changes is increasing over time. This trend is especially true for offensive coordinators.

The number of in-season coordinator changes since the 2008 season. Such in-season changes are becoming more commonplace in recent years: 17 of the 26 coordinator changes from the last eleven seasons have occurred in the last four seasons. Also interesting is that these coordinator changes generally occur in groups. Seeing only one coordinator change (2008 & 2011 seasons) is less likely than seeing zero (2009, 2013, & 2014 seasons.)


This investigation becomes more striking when we break these overall numbers down into offensive and defensive categories.

Here we see a marked difference in how the league treats its defensive and offensive coordinators. There is a somewhat steady trend on defense, with roughly one coordinator change per season. Offensive coordinators, on the other hand, are suddenly much more replaceable in-season. Since the 2015 season, there have been 13 midseason offensive coordinator changes, half of all midseason coordinator changes since 2008.

The increasing instability of the offensive coordinator position comes at a time when the NFL sees an increased emphasis on offense overall. Offensive numbers, especially through the air, have been notably inflated over the past several years, leading multiple teams to attempt to find the latest and greatest young offensive mind at the coaching level.

This offensive explosion appears to make teams more impatient with their current offensive infrastructure. Such is the case in Jacksonville this week, where Nathaniel Hackett’s replacement occurred concurrently with the benching of embattled starting quarterback Blake Bortles.

In our next article examining in-season coordinator changes, we’ll look at the outcomes of such moves, and examine whether or not such an in-season replacement yields increased performance.

*Coordinator changes include both coordinator firings and when head coaches relent their play-calling duties.

By Wyatt Taylor

Despite making the playoffs in the 2017 AFC South, the Tennessee Titans fired Mike Mularkey during the 2017-2018 offseason, replacing him with first-time Head Coach Mike Vrabel. Vrabel’s name should be familiar to most NFL fans. He served as a starting linebacker during the early parts of Bill Belichick’s New England Patriots dynasty, while displaying a surprising talent as an offensive red-zone weapon: Vrabel caught 12 passes during his playing career, ALL 12 of which went for touchdowns.

After retiring, Vrabel dropped to the college level, spending three years on the Ohio State defensive staff, before returning to the pro game under Bill O'Brien in Houston. Vrabel led the Texans’ Linebackers for three seasons until earning a promotion to Defensive Coordinator in 2017. The Texans defense improved massively in Vrabel’s one season as DC, finishing 13th in the league for yards given up, compared to dead last - 32nd - the year before.

The Vrabel hiring represents a 180 degree move away from Mike Mularkey. Titans fans were unimpressed by Mularkey from the start; the team removed the interim tag from his position after the 2015 season, during which the team had gone 2-7 under Mularkey after the midseason firing of Ken Whisenhunt. Despite two straight 9-7 seasons and one playoff loss to the 2017 Patriots, Mularkey was often criticized for an uninspired offense in which third-year Quarterback Marcus Mariota seemed to regress from a strong 2016. By bringing in Mike Vrabel, the Titans hope to bring in a young star player-turned coach who’d served under successful head coaches at every level (Bill Belichick, Andy Reid, Urban Meyer, & Bill O’Brien).

Vrabel’s defensive background would hopefully allow the strong Titans defense to continue its upward trajectory, and by bringing in a younger offensive staff would allow Mariota to flourish into the star that he seemed to be in 2016. To this end Vrabel hired Matt LaFleur as Offensive Coordinator, following one year in Los Angeles where LaFleur seemingly re-invigorated the Rams offense, especially quarterback Jared Goff.

In short, the Tennessee Titans hope to capitalize on the untapped potential of a young and successful team. A top-tier defense should continue to come into its own with the introduction of a defensive minded Head Coach, while a young and innovative Offensive Coordinator should allow dual-threat quarterback Marcus Mariota to do what he’s comfortable with. The Titans hope that by replacing an aging coach staff, their upward trajectory should continue.

However, Titans fans will not like to hear it, but history does not support this hope. Since, 1990, 17 teams have replaced their Head Coach after a 9-win season. Those teams averaged roughly 8 wins the next season, by itself bad news for Titans fans. Like the Tennessee Titans, 10 of those 17 teams hired a first-time Head Coach, averaging only 6 wins the next season.

Not to intentionally bring down Titans fans even more, but a number of statistical analyses show that 9-wins is a significant record at which a first-time Head Coach has an effect on team success. Comparisons of Means shows that a first time HC only (ONLY) has a significant effect on team wins that next season. First-time head coaches cost their teams 4.5 wins that next season.

We ran a number of more robust regression models, accounting for some relevant details of the incoming coaching staff, and a first-time head coach was shown to only have an effect at certain levels. Both 1- and 2-win teams were shown to be negatively affected by hiring a first-time head coach, which seems reasonable. Perhaps such dire situations require experience in the NFL to right the ship. The only other significant result is for those 9-win teams that replace their head coach. In the most significant finding of our models, first time head coaches are shown to be absolutely catastrophic for 9-win teams who seem right on the edge, costing their teams an astounding 6.5 wins that next season (p< .001). While the Titans young core may give fans reasons to hope, the history of 9-win teams hiring first-time head coaches does not bode well.

*HC being an NFL player, HC being Minority, HC being Offensive-minded, HC number of years coaching in the NFL, Average NFL coaching experience of Coordinators, Average NFL coaching experience of position coaches.

By Stephen Juza and Wyatt Taylor

Previously, we discussed the NFL’s trend toward rookie head coaches. The past 15 years have seen teams become more likely to hire a first-time head coach, but, on average, a head coach with more seasons at the assistant level. Today, we examine how this affects their assistant coaches.

A head coach’s main responsibility is setting the overall strategy for the team, but there are far too many decisions for him to make. That’s where his assistants come in. Head coaches place a lot of responsibility on their assistants to implement their vision for the team.

It’s intuitive that a head coach can place more responsibilities with experienced coaches, and coordinators average several more seasons in the NFL than other assistant coaches. At first thought, the value in having experienced coordinators would seem to be more for rookie head coaches who may need more guidance navigating the week-to-week demands of the NFL.

A young head coach who is able to trust his coordinators to recognize and react to routine situations can spend more time perfecting higher-level strategies and gaining familiarity with the head coach role.

In the past, we mentioned the Los Angeles Rams wunderkind Sean McVay, who hired Wade Phillips as his defensive coordinator. Phillips has been a defensive coordinator or head coach in the NFL longer than McVay has been alive. By trusting day-to-day control of the defense to Phillips, McVay could focus heavily on the development of the young Rams offense and quarterback Jared Goff. In one season with McVay, Goff went from a potential bust in 2017 to a potential superstar in 2018 as the Rams made the playoffs.

Do other coaches follow a similar hiring pattern? This leads us to our first hypthosis.

Do new head coaches bring in more experienced coordinators than experienced head coaching hires?

No, rookie head coaches do not hire more experienced coordinators than experienced head coaching hires. In fact, data suggests it may be the opposite. Rookie head coaches hire coordinators with an average of 13 seasons of NFL experience. This is slightly less than the 14 years of experience coordinators bring to an experienced head coach’s staff.

We both found this result surprising. New head coaches are not filling out their coaching staffs with coaches who are about as experienced as they are. This led us to our second hypothesis focused around the rest of the coaching staff.


Is average staff experience higher overall for first-time head coaching higher than for non first-time hires?


Again no, and again the opposite is true. Despite being new to the role of head coach, first time head coach staffs tend to be significantly less experienced than the staffs of non first-time head coaches. First time head coaches will tend to hire staffs with an average of eight years of NFL coaching experience, compared to an average of nine years of experience for their non first-time counterparts.

This adds even more intrigue to their hiring of coordinators. Our analyses here tell us that new head coaches will hire less experienced coaches than their non first-time counterparts. These same new head coaches tend to hire similarly experienced coordinators as non first-time hires.


If we consider coach inexperience to be a ‘risk,’ new head coaches tend to accept that risk with the majority of their staffs. However, they may not be willing to extend that same risk when hiring coordinators. While a new head coach may not seek out a coordinator with Wade Phillip’s experience, our findings today do suggest that he will be less risk-averse at the coordinator level than with the rest of his staff.


As we continue looking into recent trends with NFL coach hiring, there are still other questions to answer:

By Wyatt Taylor and Stephen Juza

Since 2005, the NFL has continued to go through an offensive explosion across the league. In the last 13 seasons, we have seen the eight highest scoring seasons since the AFL/NFL merger in 1970. Beyond the high-scoring games, the passing game has flourished under relaxed rules.

During the 1970s, the average team passed for 156 yards per game. Between 2010 and 2017, this increased to 233 yards per game. This has come at the expense of the running game—the average rushing yards per game has decreased from 138 to 112 since the NFL merger. With the increase in offense, how has this altered the careers of head coaches on that side of the ball?

Overall, head coaching hires come from offensive backgrounds 53% of the time. This trend continued this latest offseason with four of the seven head coaching hires spending time as an offensive coordinator: Frank Reich, Jon Gruden, Matt Nagy, and Pat Shurmur.

Has the percent of offensive coaches increased over time?

Despite the increased offensive output, the percentage of offensive head coaches has stayed consistent between 1990 and 2017.


The percentage of offensive hires was virtually identical in our two time periods (1990-2004 and 2005-2017), showing no increasing preference in offensive coaches as the leader of the team. However, teams are willing to take a risk with less experienced coaches if they are offensive-minded.

Are offensive coaches hired quicker as head coaches?

Yes, offensive coaches have less coaching experience when they are hired. While the least tenured coaching hire was previously a defensive coordinator, offensive coaches typically are less tenured in the league.

Since 1990, offensive coaches average three fewer seasons of experience than other head coaching hires. Offensive head coaches are typically hired after 12 seasons of NFL coaching experience while other head coaches are just shy of 15 seasons.

Is an offensive head coach a quick route to victory?

No, new offensive head coaches see a similar increase in record in their first season at the helm when compared to other head coaches. Teams win a game and a half more in the first year of a head coach’s tenure than the previous year despite their background.

What does that mean for the latest round of new head coaches? The Titans are the only team with a new head coach that made the playoffs in 2017, finishing first in the AFC South with a record of 9-7. If the Titans win one more game in 2018 than the previous season, the Titans will be in a strong position to return to the playoffs.

On the other end of the spectrum, it could be a long season for the New York Giants under the guidance of Shurmur. Finishing 2017 with a 3-13 record, it may be a long climb back up to contention. Their best case scenario is replicating the 2008 Miami Dolphins, improving 10 wins and winning the AFE East after hiring Tony Sparano.

As we continue to investigate emerging trends with head coach hiring in the NFL, there are still many questions yet to answer:



Methods: We used t-tests to confirm that each of the findings we discuss above to be statistically significant (p < .1).

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