UCLA has the pieces for a Pac-12 title run. Can Josh Rosen make that happen?

Check out the advanced-stats glossary here. Below, a unique review of last year’s team, a unit-by-unit breakdown of this year’s roster, the full 2016 schedule with win projections for each game, and more.

Last year was supposed to be the year of the UCLA breakthrough, at least per the numbers. Jim Mora’s Bruins were projected seventh in S&P+, and on paper it was justifiable.

An offense that had improved for four straight years and was eighth in Off. S&P+ in 2014 was supposed to be built sturdily enough to take on a new quarterback.

The defense had ranked in the Def. S&P+ top 25 for two straight years and returned most of the biggest stars: linebackers Myles Jack and Deon Hollins (combined: 18 tackles for loss in 2014), linemen Kenny Clark and Eddie Vanderdoes (combined: 11 TFLs, impressive for a pair of linemen in a 3-4), and defensive backs Fabian Moreau and Ishmael Adams (combined: four TFLs, 15 passes defensed).

A top-10 projection felt too aggressive to me, considering Mora was handing the reins to a freshman, but there’s not an “Are they starting a true freshman?” tweak in the formulas.

UCLA’s upside is undeniable, but the Bruins will be playing some big road games with an unknown quantity at QB. If Josh Rosen can prove his upside enough to account for freshman mistakes, then the rest of the squad is loaded.

In a tough Pac-12 South, UCLA has more proven entities than anybody else. But the Bruins are the only South contender with an unproven quarterback. Will that cost them too much?

It did cost them a little bit. UCLA fell from 24th to 46th in Passing S&P+, and despite strong redzone execution, the Bruins slipped from eighth to 21st in Off. S&P+. But the defense we expected to see never saw the field. Vanderdoes played in one game (and was awesome) before succumbing to injury. Jack and Moreau made it three games. Adams made it 10.

At one point in November, half of UCLA’s opening-day defense was sidelined. Any semblance of efficiency was out the window. UCLA fell 49th in Success Rate+ and 62nd in Rushing S&P+. The pass defense held up admirably, but the Bruins were too inefficient and handed too many long fields to Rosen and company.

2015 was a mulligan year for Mora. Only a few schools can deal with that level of injury and continue playing at a top-10 level, and three straight years of on-field improvement halted.

Injuries can help in the future tense as much as they hurt in the present tense, however. Vanderdoes, Hollins, and Moreau are back, as is a new batch of youngsters who got more playing time than expected. There are questions on offense, where a good chunk of contributors have moved on, but on paper, UCLA should expect to bounce back considerably. And considering they only fell to 23rd in S&P+ last year, that’s pretty exciting.

In last week’s Utah preview, I noted how rare it is to improve for four straight years. At some point, you have to replace your starting quarterback. At some point, you get bitten by the injury bug.

But Mora has recruited well enough to make you think a quick bounce back is possible. Units with potential experience issues -- receiver, offensive line -- are loaded with former star recruits, and the defense now combines significant experience (every starter could be either a junior or senior) with another layer of high-upside youth to account for injuries.

And, of course, UCLA also has Rosen, a lab-created quarterback specimen who dealt with predictable learning experiences as a freshman but survived. There’s a lot to like here.

This is Bill C’s daily preview series, working its way through every 2016 team. Catch up on the Pac-12 so far!

A long time ago for ESPN Insider, I explored the idea of home field advantage, who actually has it and how you actually define it.

Think about the teams considered to have significant home-field advantages: Florida, LSU, Nebraska, Oklahoma and Ohio State. These teams’ home stadiums are absolutely intimidating, and few teams win there.

But how much of that is due to the stadium, and how much is due simply to the great teams playing there? Those teams have been great at home, but they have also been pretty stout on the road. And during down periods, these stadiums weren’t nearly as terrifying. What we consider great home-field advantage is, as much as anything, simply great teams playing at home.

In the end, you can really only compare a team’s home results to its road results to determine an home-road split, but not home-field advantage. This split can be caused by underachieving on the road or overachieving at home, but there are certainly teams whose performance at home and on the road have varied significantly.

Teams in off-the-beaten-path locales like Syracuse, Penn State, and Texas Tech tended to have the largest home-road splits, meaning either that they play particularly well at home, particularly poorly on the road, or both.

In 2015, UCLA played the same everywhere.

The Bruins looked great at home in September and laid an egg against Washington State in the home finale; they got blitzed at Stanford and Arizona State (and “at” crosstown rival USC) but handled UNLV and Oregon State with ease and played wonderfully in a 17-9 road win over Utah. They were up and down both in and out of Pasadena.

You can spin this however you want. If you want to look at this as a great sign -- UCLA as potential road warrior, and with a freshman quarterback no less! -- go for it. If you choose to note that the Bruins got no boost in the cavernous Rose Bowl, you can do that, too.

I’m not sure what the answer is, but I can note that of five projected top-40 opponents in 2016, three come to Pasadena. Make of that whatever you like.

After four years of producing top-30 offenses in the Rose Bowl, offensive coordinator Noel Mazzone left to attempt to give the underachieving Texas A&M offense a shot in the arm. Mora elected to promote from within, handing running backs coach Kennedy Polamalu the coordinator role.

Polamalu, a former USC fullback, is promising to bring toughness, through more significant roles for tight ends and fullbacks. That means players like Nate Iese, converted defensive lineman Ainuu Taua, and converted linebacker Cameron Griffin could see the field quite a bit. It might also mean more pressure on a shaky line to improve. While Rosen remained mostly upright, the run blocking was pretty leaky.

Whatever the approach, the primary goal will be better establishing it. Rosen showed a pretty exciting knack for bailing UCLA out on passing downs -- the Bruins ranked 30th in Passing Downs S&P+ -- but he was asked to do it too frequently because they were a pretty mediocre standard downs team. His passer rating on first down: 127.3. His passer rating on third-and-10 or more: 145.4. That’s not how that’s supposed to work.

If fullbacks and tight ends can help with efficiency passing and a run game that could feature three exciting backs (Soso Jamabo, Nate Starks, Bolu Olorunfunmi), UCLA will have cleared a huge hurdle and opened up the next big question: Do the Bruins have the receivers Rosen needs?

Note: players in bold below are 2016 returnees. Players in italics are questionable with injury/suspension.

Rosen is already pro-caliber when it comes to avoiding hits. Per game, he only took one sack and rushed twice, and his ability to maneuver in the pocket was beyond his years.

This is good because he really, really, really needs to stay healthy for UCLA to succeed. Last year his only viable backup was Jerry Neuheisel, and “viable” may have been pushing it.

This year, it’s former walk-on Mike Fafaul and a couple of freshmen who aren’t nearly as well-touted as Rosen. Could they steer the ship for a few plays or drives? Sure. But it’s hard to imagine UCLA coming anywhere close to the Pac-12 South title if anyone other than Rosen is behind center.

Paul Perkins was one of my favorite backs in the country last year, possessing a rare combination of power and explosiveness. He was also the least efficient back in the UCLA arsenal. He rushed for five yards or more in 39.7 percent of his carries; his top three backups did the same 44.7 percent of the time, and with the same level of explosiveness.

That doesn’t guarantee that Jamabo or anyone else produces the same level of overall success as Perkins, but it’s a positive sign. If Polamalu’s goal is to establish the run as part of a physical offense, he seems to have the toys in the backfield to do so.

The receiving corps, however, faces a pretty significant reset. Only one of last year’s top five targets returns; Jordan Payton, Thomas Duarte, Perkins, and Devin Fuller combined for 22 targets, 14.2 catches, and 190.7 receiving yards per game. And of this year’s returnees, only senior Kenneth Walker III and sophomore Stephen Johnson had the chance to prove any sort of explosiveness.

Strong recruiting rankings are about odds as much as anything else -- the more star recruits, the higher the ranking, the more likely you are to find someone capable in a given role. From this perspective, the odds of some solid weapons emerging are pretty good. Johnson, juniors Eldridge Massington and Alex Van Dyke, and three freshmen (Theo Howard, Damian Alloway, Dymond Lee) are all former four-star recruits, and another four-star, converted cornerback Ishmael Adams, evidently joined the receiving corps this spring. Athleticism certainly isn’t an issue.

Still, this is a bit scary. Continuity in the receiving corps is important, and Rosen is going to be surveying a field full of receivers he didn’t establish much of a rapport with last fall. Add in a new center and right tackle, and you’ve got a recipe for regression. Or at least, if Rosen improves, it might be hard for the overall Passing S&P+ to improve, too.

It was the same story for UCLA’s defense: The Bruins did some impressive things on passing downs but weren’t good enough on standard downs. They were strong on third downs but weren’t good enough on first downs. They allowed 4.4 yards per carry on first down and 3.4 on third, a 122.1 passer rating on first and a 101.1 on third.

None of these numbers are awful, mind you. But adjusting for opponent, the Bruins were 50th in Standard Downs S&P+, which offset a No. 11 ranking on passing downs.

Second-year defensive coordinator Tom Bradley, a longtime Joe Paterno assistant, didn’t have the pieces to play his make-fewer-mistakes-than-them defense. But by simply being able to field the same lineup from week to week, he should be able to engineer a rebound in 2016.

Four of last year’s top five linemen return, as does Vanderdoes. Four of last year’s top six tacklers at linebacker are also back, as are nine of 10 defensive backs, plus Moreau. This has gone from a thin, banged-up unit to one of the Pac-12’s most experienced.

UCLA’s deficiencies were obvious. Without Vanderdoes and Jack, and with only three starters or backups managing to play in all 13 games, the Bruins couldn’t establish enough of a presence near the line of scrimmage. They ranked 92nd in passing downs sack rate and an egregious 123rd in stuff rate and 127th in power success rate. Even accounting for injuries, UCLA’s recruiting should have produced more sturdy havoc options than that.

That Vanderdoes is back is obviously a good thing. But a front seven that was in no way disruptive must replace its only two interesting attacking pieces, tackle Kenny Clark and OLB Aaron Wallace. UCLA has experience and girth up front, but the Bruins might have to rely on youth to create more of an attacking presence. Redshirt freshmen like end Rick Wade and OLB Keisean Lucier-South certainly have the credentials, as does true freshman Mique Juarez. If UCLA can start making plays at the line instead of about five yards downfield, that would significantly help a secondary that was already good with little help.

With no pass rush and no Moreau, UCLA still ranked 18th in Passing S&P+. That’s an exciting sign, especially considering how much continuity there is in the secondary in 2016. The only loss is Ishmael Adams, and he could flip back from receiver if necessary.

Moreau’s return means high-level competition for playing time at cornerback. Senior Marcus Rios, junior John Johnson, and sophomores Adarius Pickett and Denzel Fisher all return and are joined by two four-star redhisrt freshmen. And at safety, Jaleel Wadood and Randall Goforth might be the best tandem in the conference. UCLA allowed only 29 passes of 20-plus yards last year, 10th in the country. Not bad considering the help the Bruins weren’t getting from their front seven.

If Vanderdoes, a resilient Hollins, and maybe a couple of youngsters can provide more of a pass rush (and a few more passing downs), this could easily be a top-10 pass defense. But that’s a relatively significant if.

Ka’imi Fairbairn was incredible in both the place-kicking and kickoffs departments. Despite inconsistent returns and punting, UCLA ranked 33rd in Special Teams S&P+ almost solely because of Fairbairn. And now he’s gone, just like everybody else. UCLA certainly has the athletes to field decent return teams and coverage units; do the Bruins have decent new legs?

UCLA’s 2016 schedule is a lesson in odds and probabilities. As you see, the Bruins are favored in all 12 games, suggesting that they aren’t far from a huge season. But in four of those games, they are given between a 51 and 61 percent chance.

And these odds are based on normal home-field adjustments. If last year is any indication, maybe add a few percentage points to the road games and subtract a few from the home games.

With inconsistency on offense, UCLA was never going to be the top-10 team it was projected to be on paper last year. But the injury bug bit a few incredibly important players on defense.

Health and experience should help to shore up, but questions remain. Will an attempt to bring more power and run capability to the offense pay off? When it’s time to throw, does Josh Rosen have the receivers? And while the pass defense could be elite, will it matter if the run defense improves?

Arizona and Arizona State have some retooling to do, and odds aren’t in favor of Utah continuing to improve without hitting a bump or two. The Pac-12 South could be a two-team race between UCLA and USC.