You may not believe this, but there was once a time that Arkansas consistently had an elite defense. That time was back during the Golden Age of Arkansas Football (1959-1989), an era that ended not long after Jack Crowe was promoted to head coach in 1989.

That era is long past. Arkansas is in a different conference, dealing with different demographics (both in-state and in terms of recruiting grounds), and facing different challenges from opposing offenses.

This week’s news that Robb Smith is headed to Minnesota is hardly surprising. Bret Bielema doesn’t like to “fire” assistant coaches, preferring instead to help them land other jobs. Arkansas’ defense tanked in 2016 despite returning nine starters from an unimpressive 2015 unit.

Smith’s departure means he won’t have a chance to challenge Willy Robinson for the title of longest-serving defensive coordinator since Arkansas joined the SEC in 1992. Yes, Robinson at four years is the most.

The Hog defense appears to have hit its decline when Bobby Petrino was hired in 2008 and brought in Robinson to be his defensive coordinator, although that statement is hardly fair to either man. Petrino brought a better offense, thus making the defensive struggles more excusable, and Robinson was dealing with a much stronger SEC than Houston Nutt’s defensive coordinators were.

Run defense bottomed out under Smith in 2016, while pass defense tends to fluctuate, based on quality of secondary and pass-rush.

In the search for the new defensive coordinator, we must consider several things:

What defensive schemes can Arkansas reasonably recruit and develop talent for, given recruiting limitations?

Which positions have, historically, been the easiest for Arkansas to recruit and develop, and which defensive schemes will prioritize these positions?

What traits do all of Arkansas’ great defenses over the last several years have in common?

Let’s take a closer look at Arkansas’ best defenses from 1998 to 2016 and see if they can shine some light over the best possible path forward.

1998-1999: Burns’ attacking 4-2-5

Danny Ford left Arkansas’ program better than he found it, but didn’t get a chance to reap the rewards of recruiting after going 4-7 in 1997. Arkansas was still in the SEC cellar, and Houston Nutt was called upon to revitalize the program. If that was the aim, he succeeded.

Arkansas went 9-3 in 1998 – including an 8-0 start – behind a dominant defense and improved offense. Nutt’s offensive changes drew more attention: he fixed Arkansas’ pass protection problems in part by returning four starters up front, and in part by adding more quick passes and rollouts to the playbook to keep Clint Stoerner upright. He fixed Arkansas’ run game problems in part by getting Madre Hill back from season-ending injuries in 1996 and 1997, and in part by having his fullback play close behind the quarterback to allow him to get into the hole quicker. It was a nifty innovation that worked well.

Defensively, Nutt hired Keith Burns, an Arkansas alum, away from USC, where he had been defensive coordinator for four years. Burns understood how to build a strong defense at Arkansas. The Hogs historically have problems recruiting “traditional” linebackers, so Burns’ scheme deemphasized the role of a big middle ‘backer. The Hogs also lacked size on the defensive line, so Burns got away with smaller, swifter linemen.

Here’s what Burns’ 4-2-5 defense looked like:

The 4-2-5 was a trendy defense at the time, as it was an adaptation of the 4-4 Robber that Frank Beamer and Bud Foster were using to turn Virginia Tech into a national power. It made extensive use of linebacker/safety hybrids, utilizing positions called bandit (“B” in the diagram) and rover (“R”), which are basically strong and weak safeties with some linebacker roles. The defense requires an excellent free safety and at least one great cover cornerback, and Burns had both of those in Kenoy Kennedy and David Barrett, who had all-SEC seasons.

The defense was also highly simplistic, with only a small number of personnel groupings, formations, stunts, and blitzes, and very generic language. (For example, “TON” is a stunt where the tackle crosses over the nose, while “NUT” is the opposite. Get it?)

For more on Burns’ defense, check out his 1997 USC playbook. (It’s the same thing he ran at Arkansas. If anyone has an Arkansas copy, I’d love to see it.)

With Kennedy the eraser on the back end, Burns was able to blitz constantly. Arkansas recorded a staggering 42 sacks in 1998, more than in any year since. Zac Painter, the rover, picked off 6 passes, and the team intercepted 19 passes, also more than in any year since. And the pass-rush came without a dominant sack artist. C.J. McLain led the Hogs with 7 sacks, but 7 sacks don’t even make the top ten single-season performances from 1998-2016. Eleven different Hogs recorded at least 2 sacks, and 16 had at least 1.

The Hogs did all of these with players from common recruiting areas: Kennedy and Flowers were from Dallas. Defensive tackle Ryan Hale was from Rogers, while the other starting tackle, Melvin Bradley, was from Barton. Painter was from Jonesboro. End Carlos Hall was from Marianna. Barrett was from Osceola. Linebacker J.J. Jones was from Magnolia. Defensive back Jeremiah Harper was from Mayflower. The list goes on and on.

Statistically, Kennedy led both the 1998 and 1999 teams in tackles, with 105 both seasons. No linebacker ranked in the top five of the team in tackles in 1998, but Jamel Harris and Quenton Caver were second and third in 1999. Arkansas surrendered just 2.9 yards per rush in 1998, and 2.7 in 1999. Both marks are significantly better than any Arkansas defense since.

Burns left for the Tulsa head coaching position after the 1999 season, the start of a sudden downturn that now finds him coaching high school football in California. New defensive coordinator John Thompson (mostly) kept the 4-2-5 in place in 2000, plugging true freshman Ken Hamlin of Memphis into Kennedy’s free safety role. Arkansas’ defense was worse but still decent in 2000, and improved slightly in 2001 when Thompson scrapped the 4-2-5 in favor of a 4-3/3-4 hybrid defense that was more traditional and linebacker-friendly.

2002: Wommack’s finest moment

Thompson moving to a more traditional defense made sense in 2001, since Thompson had future all-American Jermaine Petty (a junior college transfer) available at middle linebacker. Thompson plugged in sophomores Tony Bua and Caleb Miller at outside linebacker to create a pretty impressive linebacker corps. Arkansas’ typical problem with the 4-3 defense is that the Hogs have enough trouble fielding one SEC-caliber linebacker, so three is a chore.

Thompson left for the Florida DC job after the 2001 campaign, and Dave Wommack, the defensive backs coach, was promoted into the role. He mostly retained Thompson’s system and ran it from 2002 to 2004.

These diagrams are from Thompson’s 2001 Arkansas playbook. A couple of things to notice:

The terms “bandit” and “rover” have been retained, albeit in different forms. Rover still refers to the strong safety. Bandit now refers to a hybrid linebacker/defensive end position.

Notice that the defense can switch from the 4-3 to the 3-4 without changing personnel: the bandit plays both end and linebacker, while a defensive tackle can also play end.

The Hogs rotated heavily between 3-linemen and 4-linemen sets, preferring the 3-4 look earlier in the season and switching to more 4-3 as the season progressed.

The 2002 team didn’t have Petty, but it did have Hamlin, whose final season was easily his best in Fayetteville, and among the best seasons ever by an Arkansas safety. The 2002 team was devastating off the edge, with outside linebackers Miller and Bua (both had 9 TFLs and 4 sacks each) teaming with defensive end Gavin Walls (11 TFLs, 6 sacks) to create a relentless pass-rush. Teams with aggressive linebackers are often hard to run on, and that was certainly the case in 2002. Arkansas allowed 3.4 yards per rush, a big improvement over the 2000 and 2001 teams.

The 2002 team included more highly-recruited prospects than Nutt’s earlier teams, and fewer from Arkansas. Bua, Miller, and Lawrence Richardson were from Texas. Walls was from Mississippi. Hamlin was from Memphis. Ahmad “Batman” Carroll was from Atlanta. The top Arkansan was end/linebacker Jeb Huckeba, from Searcy.

Wommack’s first defense, in 2002, would be his best, carrying Arkansas to an SEC West title despite an often-lethargic offense (just 125 total yards of offense against Troy State in October). The 2003 unit, despite returning most everyone except Hamlin, regressed against the run, then everyone left, and Wommack’s depleted 2004 unit was by far the worst of the Nutt era. He was fired after that season.

2006: Herring turns ‘em loose

Nutt tapped NC State defensive coordinator Reggie Herring to replace Wommack. Herring was, in my mind, a very underrated defensive coordinator, whose entire time in Fayetteville was overshadowed by Darren McFadden and Nutt-related drama on the other side of the ball. Herring wasn’t particularly likeable personally, but the numbers suggest he was laying a good foundation during his time at Arkansas.

Herring learned the 4-3 “Over” while coaching at Oklahoma State under the man who invented it, Arkansas alum Jimmy Johnson. The Over, also known as the “Miami 4-3”, is a speed-based defense that allows linebacker-challenged teams to still run a 4-3 defense.

The “Over” slants the defensive line towards the strong side, with the nose shading to the weak side and the namesake defensive tackle (called the “over tackle” in this system) playing on the shoulder of the strongside guard. The weakside defensive end plays very wide and tries to use his speed to get around the tackle. The objective is to use the defensive line to clog the strong side and take away run plays, while the weakside defensive end brings a big pass rush.

The system counts on undersized guys to create havoc using their speed. In his first season, Herring asked a sophomore wide receiver to put on weight and move to defensive end: less than two years later, Jamal Anderson was drafted in the first round of the NFL draft. Other undersized guys, like weakside linebacker Sam Olajabutu, fit perfectly into this system.

The 2005 defense is best-known for giving up 70 points to USC in the Coliseum, but that’s an unfair way to remember it, given how strong the defense finished the year and that, overall, it was a big improvement over the 2004 defense despite a scheme and coordinator change. Herring’s main task was to get some productivity from a defensive line that had been very unproductive over the 2003 and 2004 seasons. Anderson’s move to defensive end helped: his coming-out party came in a 41-17 win over Mississippi State in the next-to-last game. The emergence of nose guard Keith Jackson Jr. helped as well.

In 2006, it all fell into place for Herring. I think this play, from the 2006 Tennessee game, best shows what Herring was trying to build in Fayetteville:

Now that’s some SEC speed.

Olajabutu led the 2006 team in tackles, but it was the productivity of the defensive line that stood out. Anderson totaled 19.5 TFLs, 13.5 sacks, and 26 quarterback hurries – all the most during the period 1998-2016. Fellow end Antwain Robinson had 8.5 sacks and 15 hurries, while Jackson Jr. had 16 hurries.

Anderson (two-star recruit at receiver), Jackson Jr. (three stars), Robinson (three stars), and tackle Marcus Harrison (two stars) all hailed from Little Rock.

In the secondary, the Hogs were excellent against the pass, with cornerback Chris Houston (three stars) becoming a star in Herring’s strict man-to-man defense. Unlike Burns’ attacking defense of 1998-1999, Herring’s defense didn’t ask much of the safeties: free safety Kevin Woods (two stars) had a good but quiet year, while strong safety Randy Kelly (two stars out of juco) was used a force player against the run more than as a pass defender.

The 2006 defense is the second-best over the last 19 years in scoring defense, and its 3.5 yards per rush allowed is tied with 2014 for fifth-best (behind 1998, 1999, 2002, and 2012).

Arkansas lost virtually everyone after the 2006 season, and had to totally rebuild the defense. The defense was certainly worse, but on a per-play basis, it’s still better than every defense since, except 2010 and 2014. Lost in the McFadden record-breaking and off-field drama that ultimately got Nutt fired is the fact that the 2007 defense led the NCAA in yards per pass attempt (5.5, a modern school record) and completion percentage (46.6%), while ranking second in opponent passer rating (86.7). Michael Grant also broke up a school-record 20 passes.

2010: Robinson does it his way

Here’s guessing that Bobby Petrino didn’t care too much about the history of Arkansas defense when he brought in Willy Robinson from the NFL ranks. Petrino’s offense overshadowed Robinson’s defense anyway, which is a shame, given that Robinson’s 2010 unit was actually pretty good.

Robinson’s 4-3 defense was pretty traditional, counting on a big defensive line, at least two good linebackers, and good safety play. The “under” front shifts the defensive line back to the weak side, so the nose shades to the strong side and the defensive tackle plays off the weakside guard’s shoulder: basically the opposite of Herring’s over defense. To fill the gap on the strong side, a linebacker plays outside the tight end near the line of scrimmage.

Robinson’s first unit was filled with square-peg-round-hole players suited for Herring’s system. Defensive linemen like Malcolm Sheppard (14.5 TFLs, 6.5 sacks) and Adrian Davis (8.0 TFLs, 5 sacks) had good 2008 seasons, only to regress over the rest of their time on campus as Robinson’s system took hold. By 2010, Arkansas’ defensive line had returned to being less active, although a pass-rush led by Jake Bequette (7 sacks) and Tenarius Wright (6 sacks) always seemed to show up in big moments.

The real MVPs of the 2010 team were the linebackers, who had more TFLs than the linemen. Jerry Franklin (13 TFLs, 6.5 sacks), Jerico Nelson (11 TFLs, 2.5 sacks), and Anthony Leon (12.5 TFLs, 2.5 sacks) were very disruptive, and the Hogs actually ended up with 36 sacks, one fewer than in 2006.

Overall, despite giving up 65 points in a loss to Auburn, the 2010 defense ranked 15th in S&P+, one ahead of the 2006 unit (16th) and 10 behind the 2014 one (6th).

Perhaps that’s why it is such a mystery that the 2011 team regressed. The Hogs plummeted to 50th in S&P+. Sacks fell from 36 to 29. TFLs fell from 95 to 77. Arkansas’ pass defense got slightly better, but the run defense got worse.

Robinson was fired after the 2011 season, and Petrino brought in Paul Haynes, who promised to fix the run defense. It’s hard to judge Haynes based on the disastrous 2012 campaign, but he did keep his promise: Arkansas went from allowing 4.3 yards per rush in 2011 to allowing just 3.4 in 2012, the fourth-best since 1998.

2014: Robb Smith’s restoration

Bielema brought in Smith to do a quick-fix on a defense that finished at the bottom of the SEC under Chris Ash in 2013. The quick-fix worked, but in the long run, the duct tape didn’t hold.

Smith coached under Greg Schiano, making him a part of the same Jimmy Johnson-Butch Davis-Randy Shannon tree that also spawned Herring, but Smith didn’t run the Miami 4-3 in Fayetteville. Instead, Smith kept the “under” front, which played right into the talents of his best defenders.

The weakside “triangle” of end Trey Flowers (15.5 TFLs), tackle Darius Philon (11.5 TFLs), and linebacker Martrell Spaight (128 tackles, 10.5 TFLs) was ridiculously productive, allowing Arkansas to totally shut down the run in many games, allowing just 3.5 yards per rush.

The Hogs’ 81 total TFLs is decent, but Arkansas didn’t have many sacks: just 24, fewer than almost every season since 1998, and a far cry from the better years (42 in 1998, 37 in 2006, and 36 in 2010). Role players including middle linebacker Brooks Ellis (72 tackles), nose guard Taiwan Johnson (8 TFLs), and free safety Alan Turner helped the Hogs finish 10th in S&P+ and shut out Ole Miss and LSU down the stretch to get bowl-eligible.

So why did the Smith era fail? Ultimately, it came down to pressure. After Flowers, Philon, and Spaight left after the 2014 season, the Hogs had no disruption up front. The 24 sacks in 2014 gave way to just 20 the following year, while TFLs declined from 81 to 69. Arkansas’ secondary got exposed by quarterbacks who had all day to throw. In tinkering to fix the pass-rush, the run defense broke in 2016, as the Hogs allowed a school-record-worst 5.9 yards per rush.

So what can we learn?

The past gives us some key lessons.