This preview originally published March 7 and has since been updated.

You get better by making good hires. That goes for conferences, too. We talk a lot about potential and markets and history and geography and all sorts of factors that go into improving as a group, but the straightest line between where you are and improvement is, simply, hiring good coaches.

Case in point: Here’s a chart of S&P+ averages by conference and year.

Some of the large changes you see are due to conference realignment. The Big East got raided, changed names, and dropped. The Mountain West lost Utah and TCU and dropped. The Pac-12 added Colorado at its most dismal and dropped. Conference USA (and, to a degree, the Mountain West) took on a bunch of start-ups and fixer-uppers and dropped. Et cetera.

That said, a lot of these upward and downward trends have to do with the coaches walking in and out the door.

North Texas Mean Green Head coach: Seth Littrell (5-8, second year) 2016 record and S&P+ ranking: 5-8 (107th) Projected 2017 record and S&P+ ranking: 6-6 (106th) Biggest strength: The pass defense should again be aggressive and efficient (though that will matter more if the run defense improves). Biggest question mark: UNT had a pass-first offense that couldn’t pass. Can a sophomore quarterback find a better rhythm with a shuffled receiving corps? Biggest 2017 game: There are two. With a win at SMU (Sept. 8), the Mean Green will be well on their way to a bowl. But with losses to SMU and UTSA (Oct. 13), the path to the postseason gets dicey. Summary: Littrell dragged North Texas from one win to five in his first year. If his squad makes offensive strides with a second-year quarterback, more improvement could be forthcoming.

The Sun Belt of 2012 boasted Gus Malzahn, Mario Cristobal, and Willie Taggart, plus the peaking Todd Berry and Mark Hudspeth.

The surging Pac-12 of 2013 included new additions Rich Rodriguez, Todd Graham, Jim Mora, and Mike Leach.

The drastically improved ACC of 2013 had recently added Larry Fedora and Paul Chryst and featured two elite coaches (Dabo Swinney, Jimbo Fisher) coming into their own. By 2016, the league added coaches like Bobby Petrino, Mark Richt, and Pat Narduzzi and surged even further.

Conference USA has been pretty dismal for a few seasons now. It rose in 2014, but that was primarily due to a surge by Marshall. After peaking at an average S&P+ rating of minus-3.3 in 2008 and nearly matching that in 2011, the conference has been demonstrably worse.

There could be a surge coming, though. And if it happens, hires are predictably the reason. Two have earned quite a bit of recent attention: Butch Davis at FIU and Lane Kiffin at FAU. This duo could drastically change recruiting within the state of Florida and beyond.

But if this rise occurs, it began last year when UTSA brought in Frank Wilson and North Texas hired Seth Littrell.

Wilson got headlines with his recruiting ability and his LSU ties. But the job Littrell did in restoring respectability in Denton was also fantastic.

UNT wasn't an amazing team in 2016. But the story is just how bad the Mean Green were in 2015, Dan McCarney's last year. In just two years, UNT fell from 9-4 and 39th in S&P+ to 1-11 and 128th. The 2015 Mean Green upset UTSA and lost their other 11 contests by an average score of 43-14. They scored more than 24 points just twice; they allowed fewer than 24 points just twice.

This was a miserable, identity-free team. And while Littrell cut his teeth on the offensive side (he spent time as coordinator at Arizona and Indiana), UNT improved on both sides of the ball -- their S&P+ rating (presented as an adjusted points per game average) improved by 6.6 points on offense and 6.2 on defense. Hell, special teams improved by 1.7 points as well.

This was significant improvement for one's first year. Granted, North Texas won just five games and squeezed into a bowl on a technicality, but ... that's still a four-win improvement.

It could just be that UNT was artificially, unsustainably bad in 2015. McCarney’s collapse was sudden, and maybe the Mean Green would have improved even with McCarney in 2016. But when this across-the-board level of improvement takes place under your watch, you get the benefit of the doubt for a while. And when you return most of the reasons for that improvement, you suddenly find yourself facing some expectations.

2016 in review

2016 North Texas statistical profile.

The impressive part was that the Mean Green were competitive at all. But for about half a season, they were more than that.

First 7 games (4-3) — Avg. percentile performance: 40% (~top 75) | Yards per play: Opp 5.5, UNT 4.9 (-0.6) | Avg. performance vs. S&P+ projection: plus-9.7 PPG

— Avg. percentile performance: 40% (~top 75) | Yards per play: Opp 5.5, UNT 4.9 (-0.6) | Avg. performance vs. S&P+ projection: plus-9.7 PPG Last 6 games (1-5) — Avg. percentile performance: 26% (~top 95) | Yards per play: Opp 6.8, UNT 5.3 (-1.5) | Avg. performance vs. S&P+ projection: minus-11.3 PPG

The offense began to show some life as the year unfolded, while the defense gave out. Still, the early run of decent play, combined with iffy competition, meant that the Mean Green were at .500 heading into November. And though they finished with losses in three of four games and fell to 5-7 overall, their high APR score — a parting gift from McCarney — earned them a spot in the Heart of Dallas Bowl, where they made a late comeback against Army before falling in overtime.

The defense may have faded, but it drove UNT’s wins. The Mean Green allowed only 23 points per game in their wins and played at a 40th percentile level or higher nine times. That isn't the highest bar, but the offense only hit that level six times.

We’ll see how much this shifts in 2017; the offense returns a bit more than the defense does.

Offense

Full advanced stats glossary.

It made sense that Graham Harrell's first season as UNT coordinator was a struggle. He and Littrell took over a unit that not only ranked 123rd in Off. S&P+ the year before, but also did none of the things that they want their offense to do.

Both Harrell and Littrell have air raid ties. Littrell was at Oklahoma when Bob Stoops brought Mike Leach to town, and he served four years as Leach's running backs coach and later spending two years under former Oklahoma coordinator Kevin Wilson. Harrell played for Leach (he was quarterback when Littrell was RBs coach) and spent 2014-15 coaching Leach's outside receivers.

Everybody brings their own influences and intentions, but safe to say both Littrell and Harrell want to be able to wing the ball around. And the offense they inherited ranked last in FBS in Passing S&P+. This was a run-first offense that couldn't throw and moved slowly. Switching to a pass-first attack was going to take a while.

There were bursts of improvement. After gaining just 53 total yards (!) against Florida, North Texas scored 42 points against Rice, 38 against Marshall, and 35 against Army. And after a lull, they averaged a not-awful 28 points per game over their final three contests.

Still, the passing game never really clicked, and UNT improved to only 122nd in Passing S&P+. In a pass-first attack, that's a bit of an issue. But that's what happens when you not only install a new attack, but also put a freshman in charge of it.

Mason Fine took his lumps. Just a few months after Senior Prom in Locust Grove, Okla., Fine was attempting 22 passes (and completing only six) against the vaunted Florida defense. He had relative highs (723 yards, three touchdowns, and no interceptions against Rice, MTSU, and Marshall) and lows, he took 36 sacks, and he suffered an injured shoulder and ceded the floor to Alabama transfer Alec Morris.

Morris is gone, so this is probably Fine's show in 2017. He managed a low interception rate during his 2016 travails, and he's no longer a freshman. He's got an experienced line that boasts honorable mention all-conference left tackle Jordan Murray and six others with starting experience. And in senior running back Jeffery Wilson (5.5 yards per carry plus 29 receptions), he's got a versatile weapon. [Update: FCS backup Loren Easly has transferred from Stephen F. Austin. Also coming up: JUCO OL Sosaia Mose.]

What we don't yet know is whether he's got any receivers. Only one (Thaddeous Thompson) managed a 50 percent success rate or 12.5 yards per catch in 2016, and he's gone. In all, UNT quarterbacks targeted eight players more than 15 times last year, and only three return. Having a little experience at QB is a good thing, but it's mitigated if that passer doesn't know his receivers.

After losing Thompson and Kenny Buyers, UNT will need to break in a new set of inside receivers. But there's potential. Sophomore Tyler Wilson fits the slot receiver mold perfectly, as do redshirt freshan Deion Hair-Griffin and incoming three-stars Tre Siggers and Jaelon Darden. Siggers' senior highlight film is particularly exciting — he combines quickness and speed with a streak of brazenness.

If the inside guys are providing decent efficiency, the outside guys could be alright. Senior Turner Smiley came on late in 2016 (last three games: 20 catches, 266 yards), and there could be a reliable contributor among the trio of junior O'Keeron Rutherford and sophomores Rico Bussey Jr. and Kelvin Smith. Meanwhile, three-star JUCO Jalen Guyton, maybe the star of Littrell’s 2017 signing class, is making an impact in spring ball.

Still, with this much turnover in the receiving corps, you can't set the bar for improvement high. Steady play from Wilson will be key to this offense's progress.

Defense

First things first: kudos to North Texas for creating stats that made its defensive radar look like its logo. Tough to do.

For co-coordinators Troy Reffett and Mike Ekeler (who has departed for UNC, leaving Reffett as solo coordinator), the first year was a bit more successful than Harrell's. The Mean Green boasted an aggressive, efficient defense that rendered opponents one-dimensional, especially later in the year, and if you couldn't run, then you were going to struggle.

If you could run, then you weren't going to find much resistance. Still, UNT improved from 120th to 93rd in Def. S&P+. It's hard to ask for too much more than that out of the gates.

We'll go with the bad news first: there's no immediate reason to believe that the run defense will be better. UNT still ranked 110th in Rushing S&P+ and must now replace four of its top seven tacklers on the line, along with the top two linebackers. Granted, losing contributors from something bad doesn't automatically make things worse, but it doesn't make it better either.

There are some play-makers back, at least. Junior Brandon Garner and senior Joshua Wheeler combined for 13.5 tackles for loss and nine sacks last year, and the nose tackle duo of Roderick Young and T.J. Tauaalo was disruptive at times. Still, the run defense faces the burden of proof.

The weakness might not get stronger, but the strength might not get weaker, either. UNT must replace safety James Gray and corner Chad Davis in the secondary, but eight of the top 10 tacklers return. That includes senior safety Kishawn McClain (UNT's leading tackler, who combined five tackles for loss with six passes defensed), corners Nate Brooks and Eric Jenkins (combined: 7 interceptions, 14 breakups), and nickel backs Ashton Preston and Dee Baulkman (combined: 10 TFLs).

North Texas doesn't have the heft required to play sturdy run defense. Or at least, if it does, it's not obvious where that heft comes from. But in the speed department, the Mean Green have quite a bit to offer.

Special Teams

Special teams was a strength for UNT. Eric Keena's kickoffs and punts were high and deep, Trevor Moore was automatic inside of 40 yards, and returns were decent.

Good news, bad news: Keena is gone, but Moore and the return men are back. Keena was by far the strongest weapon in the special teams arsenal, but if Moore is still solid, the Mean Green's special teams grade (34th last year) shouldn't drop too far.

2017 outlook

North Texas has long been a program with potential. It's proximity to a wealth of recruiting talent was exemplified by the fact that the Mean Green would always turn into a powerhouse back in the early days of EA's NCAA Football. Their promise got the school invited to Conference USA even though, in their last eight years in the Sun Belt, they averaged just 2.8 wins per year.

It's been hard to live up to this promise, at least since the turn-of-the-century glory days under Darrell Dickey. But Littrell's first year at least crystallized what the program could become.

I'm trying hard not to overstate things -- five wins and an S&P+ ranking in the 100s is far from clear proof of concept -- but I've been impressed so far. And if a second year in the system creates offensive growth to pair with another solid pass defense, then a second straight bowl bid seems within reach.

S&P+ projects a six-win season, but there's only one game on the schedule (Week 3 at Iowa) with a win expectancy under 30 percent. Almost every game is winnable or losable, and if North Texas improves again, then that could mean another three- or four-win improvement.

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