The 2016 regular season has drawn to a close, and with it, another season with incredible highs and lows from the big guys in the trenches have been recorded in the Pro Football Focus database.

We have seen a season in which some offensive lines have been the bedrock of their offense—the foundation on top of which everything else is built—and others have been the sand upon which their figurative houses have been built.

We're going to take a run through the league and rank every offensive line in the NFL this season, from best to worst, based largely on PFF's grades, but also factoring in external factors, such as the quarterbacks those lines were blocking for, and the kind of scheme they were blocking within.

Without further delay, here's the ranking of all 32 NFL offensive lines in the 2016 regular season:

1. Tennessee Titans (Preseason rank: 25)

Top overall grade: RT Jack Conklin, 88.9 (No. 5 among OTs)

Top pass-blocking grade: RT Jack Conklin, 88.5 (No. 7)

Top run-blocking grade: LT Taylor Lewan, 88.4 (No. 2)

It seems heretical to suggest that the Dallas Cowboys did not field the best offensive line in the game in 2016, but Tennessee’s unit really was without a weakness all season. All five starters earned impressive grades in both run blocking and pass protection, paving the way to 2,180 rushing yards as a team, 1,777 of which came from their first two running backs, DeMarco Murray and Derrick Henry. No member of the offensive line surrendered more than three sacks on the season, and while LT Taylor Lewan fell off a little as the year wore on, conceding more penalties than you would like, on the other side, rookie RT Jack Conklin earned PFF All-Pro honors. This unit may not be able to match the Dallas line in terms of its very peak performers, but there was no weak link along this chain all season long, and that’s why the Tennessee Titans finish the season as our No. 1 ranked line.

2. Dallas Cowboys (1)

Top overall grade: C Travis Frederick, 90.0 (No. 3 among centers)

Top pass-blocking grade: LT Tyron Smith, 86.5 (No. 12)

Top run-blocking grade: C Travis Frederick, 88.9 (No. 3)

At their best, this unit is the best line in football, but left tackle Tyron Smith missed time due to injury, and on the other side, RT Doug Free has been a problem player for the team, surrendering eight sacks on the season and struggling with his run blocking. At left guard, the loss of La’el Collins actually upgraded the unit, with veteran Ronald Leary having a fine season in his place. Leary didn’t surrender a sack all season, and was PFF’s No. 21 ranked guard, earning a grade of 81.8. In the middle, C Travis Frederick and RG Zack Martin were first-team PFF All-Pros this season, and the driving force of this line that catalyzed exceptional rookie campaigns from both RB Ezekiel Elliott and QB Dak Prescott.

3. Pittsburgh Steelers (14)

Top overall grade: RT Marcus Gilbert (No. 13) and LG Ramon Foster, 87.1 (No. 6 among guards)

Top pass-blocking grade: LG Ramon Foster, 89.7 (No. 4)

Top run-blocking grade: RG David DeCastro, 82.7 (tied for No. 7)

One of the most underrated stories of this season has been just how good the Pittsburgh offensive line has been. Like Tennessee, there is no weakness on this unit, and Alejandro Villanueva—a player who had previously been that weak link—has upped his game dramatically and surrendered just one sack over the final 10 weeks of the season, all while crushing players at times in the run game. The guard pairing of Ramon Foster and David DeCastro have been the strength of this unit, with Foster allowing no sacks and just one penalty all season. Even the Steelers’ bench was able to provide some quality play, with tackle Christopher Hubbard in particular showing well when he was forced into action.

4. Oakland Raiders (2)

Top overall grade: C Rodney Hudson, 88.7 (No. 4)

Top pass-blocking grade: C Rodney Hudson, 90.0 (No. 2)

Top run-blocking grade: LT Donald Penn, 88.3 (No. 3)

Teams all try and build through the draft, but the Raiders have shown that if you have the spending money, you may be better off shooting for proven commodities when it comes to the offensive line—such is the strike rate of linemen coming into the NFL from the college game. Only Gabe Jackson among the starting five on this line was drafted by the Raiders, but he has been outshone by free-agent imports in the shape of LT Donald Penn, LG Kelechi Osemele, and C Rodney Hudson. Osemele, in particular, was a monster this season, and was narrowly edged onto PFF’s All-Pro second team by his former teammate Marshal Yanda—the league’s best guard. If not for the injury problems Oakland has experienced all season at right tackle, the Raiders would likely be higher on the list. Oakland has used four different players at RT for extended snaps; those players have combined to surrender seven sacks and 15 penalties.

5. Green Bay Packers (3)

Top overall grade: LT David Bakhtiari, 89.9 (No. 3)

Top pass-blocking grade: LT David Bakhtiari, 93.4 (No. 1)

Top run-blocking grade: C J.C. Tretter, 78.7 (No. 8)

This has been the best pass-protecting offensive line in the game, and it isn’t particularly close to the next-best side in that regard. The terror that Aaron Rodgers instills in defenses when he escapes the pocket and makes game-defining passes helps in that regard a little, but he also holds the ball longer than every other QB in the league except Buffalo’s Tyrod Taylor, so it likely evens out overall. LT David Bakhtiari surrendered just 20 total QB pressures, and is the league’s only left tackle to be charged for less pressure than the QB he is protecting (Rodgers has been at fault for 23). RT Bryan Bulaga would likely have been a PFF All-Pro had his run blocking been anything better than below-average, and while LG Lane Taylor has been able to do a reasonable job in replacing Josh Sitton as a pass blocker, his run blocking hasn’t been of the same quality.

6. Atlanta Falcons (5)

Top overall grade: C Alex Mack, 90.5 (No. 2)

Top pass-blocking grade: LG Andy Levitre, 86.4 (No. 12)

Top run-blocking grade: C Alex Mack, 91.6 (No. 1)

Free-agent acquisition Alex Mack has been a huge boost to this unit, stepping in from day one and returning to his best play, which ranks him among the best centers in the game. Mack made the PFF All-Pro second team with a grade of 90.5, just 0.2 off the highest grade over the season. The Falcons' line was at its best when blocking for the ground game, opening holes for Devonta Freeman and Tevin Coleman to combine for 1,599 rushing yards and 19 touchdowns. As a pass-blocking unit, they have been good, not great, and RG Chris Chester has struggled in that area in particular, surrendering 45 total pressures over 628 pass-blocking snaps. Atlanta was likely hoping to see a little more from LT Jake Matthews, who appeared to plateau after his big improvement a year ago, rather than continue that development.

7. Washington Redskins (12)

Top overall grade: LT Trent Williams, 92.8 (No. 1)

Top pass-blocking grade: LT Trent Williams, 90.6 (No. 3)

Top run-blocking grade: LT Trent Williams, 89.0 (No. 1)

LT Trent Williams was back to his best form, which is to say the best left tackle in the game. He missed four games through suspension, but ended the season with an overall grade of 92.8, the best mark for any offensive lineman at any position. Williams surrendered 16 total QB pressures in 12 games, and was only flagged three times, while also run blocking well. He even moonlighted at left guard when injuries forced a reshuffle mid-game. Spencer Long proved to be a huge upgrade over the level of play the team had a year ago at the center position, and when the team lost Kory Lichtensteiger to injury early in the year, it actually provided them another upgrade. Tackle Ty Nsekhe, who played 385 snaps filling in for Williams when he was suspended, also played remarkably well, allowing just one sack over the season and none in the four games that he started.

8. Philadelphia Eagles (7)

Top overall grade: LT Jason Peters, 88.3 (No. 7)

Top pass-blocking grade: LT Jason Peters, 89.1 (No. 6)

Top run-blocking grade: RT Lane Johnson, 86.7 (No. 6)

The Eagles line would have been far higher on this list if RT Lane Johnson could avoid getting himself suspended. Johnson is arguably the game’s best right tackle, but was suspended for 10 games, forcing the team to use fifth round rookie Halapoulivaati Vaitai, Allen Barbre and then Matt Tobin at right tackle as injuries prevented a settled unit. New import Brandon Brooks was excellent in his first season with the Eagles, allowing just one sack all season at guard and narrowly missing out on a spot on the PFF All-Pro team. Between injury and suspension, the Eagles were disrupted pretty significantly up front, and this unit has the potential to be better than they showed overall this year.

9. Baltimore Ravens (13)

Top overall grade: LG Marshal Yanda, 92.0 (No. 1)

Top pass-blocking grade: LG Marshal Yanda, 94.5 (No. 1)

Top run-blocking grade: LG Marshal Yanda, 84.9 (No. 3)

Rookie LT Ronnie Stanley struggled badly on either side of his injury, but those two games accounted for two of the three sacks he allowed all year, and eight of the 27 total QB pressures. Over the final eight weeks of the season, he was the league’s best pass-protecting tackle. Marshal Yanda remains the NFL’s best guard, proving it this season while flipping to the left side of the line midseason without so much as a hiccup in play. Rookie Alex Lewis struggled in his first year, but much of that was due to being forced to cover at LT instead of being allowed to settle in at LG, where his best games came.

10. New England Patriots (18)

Top overall grade: LT Nate Solder, 88.0 (No. 8)

Top pass-blocking grade: LT Nate Solder, 86.6 (tied for No. 10)

Top run-blocking grade: RT Marcus Cannon, 87.3 (No. 4)

It’s impossible to overstate the effect the return of longtime O-line coach Dante Scarnecchia has had on this unit, which was a major problem for the team a year ago. RT Marcus Cannon has gone from a liability to a second-team All-Pro, and RG Shaquille Mason has undergone a similar transformation when it comes to pass protection. Nate Solder returned to his best play after two lackluster seasons, and only the struggles of rookie Joe Thuney as a pass blocker held this line back. Thuney allowed 45 total QB pressures and was flagged 10 times over the season.

11. Buffalo Bills (10)

Top overall grade: LG Richie Incognito, 87.2 (No. 5)

Top pass-blocking grade: LG Richie Incognito, 88.8 (tied for No. 7)

Top run-blocking grade: LG Richie Incognito, 84.0 (tied for No. 7)

If Buffalo could find an answer to their right tackle issue, this line would vault up the rankings in an instant. Jordan Mills surrendered eight sacks and 57 total QB pressures over 596 pass-blocking snaps this season, fourth-most of any tackle in the game. The play of RG John Miller inside of Mills didn’t help much when it comes to pass blocking, either, giving the Bills a real issue on the right side of the line. Miller allowed four sacks and 33 total QB pressures, but did at least offset that with some strong run blocking. The left side of the line was far better, with LT Cordy Glenn allowing only one sack in 397 pass-blocking snaps before injury sidelined him, and Cyrus Kouandjio surrendering only one sack as his replacement. LG Richie Incognito was again the best player on this line, run blocking and pass blocking well over the year, backing up his strong performance from a season ago with another excellent campaign.

12. New Orleans Saints (8)

Top overall grade: RT Zach Strief, 86.8 (No. 14)

Top pass-blocking grade: LT Terron Armstead, 86.2 (tied for No. 10)

Top run-blocking grade: RT Zach Strief, 82.3 (No. 14)

Injury hit the Saints' line this season, and LT Terron Armstead—well on his way to being one of the best tackles in the league—played just 397 snaps across seven games, leaving more than one of those contents injured. The Saints didn’t have an adequate replacement plan in place, and Andrus Peat was inconsistent (at best) as he moved between left tackle and left guard all season. Zach Strief was the team’s best lineman at RT, allowing two sacks over 717 pass-blocking snaps, but Max Unger also played well in the center, giving up only 12 total QB pressures all season. If this unit gets Armstead back and healthy, it has the potential to be far better in a hurry.

13. Cincinnati Bengals (4)

Top overall grade: LT Andrew Whitworth, 91.3 (No. 2)

Top pass-blocking grade: LT Andrew Whitworth, 92.5 (No. 2)

Top run-blocking grade: RG Kevin Zeitler, 83.1 (No. 9)

This team looked to have a couple of major holes on paper heading into the season, and while Russell Bodine improved notably at center—at least as a run blocker—RT remained a problem all year, and ultimately resulted in the Bengals sitting Cedric Ogbuehi after he was at fault for nine sacks and 40 total QB pressures in 11 games. Andrew Whitworth remains one of the most consistently-excellent linemen in the game, and allowed only 15 total pressures across 637 snaps of pass protection, even if four of those 15 were sacks. Meanwhile, RG Kevin Zeitler made the PFF All-Pro second team after another fine season. LG Clint Boling has had better years for the Bengals when it comes to run blocking, and will be disappointed in that area, but his pass protection was better than a season ago, surrendering 14 fewer pressures than in 2015.

14. Kansas City Chiefs (17)

Top overall grade: C Mitch Morse, 82.5 (No. 14)

Top pass-blocking grade: G Laurent Duvernay-Tardif, 83.9 (No. 26)

Top run-blocking grade: LT Eric Fisher, 82.8 (No. 11)

The Chiefs' line is a unit that was good, but not great, across the board this season. There was no real weak link, but neither did anybody really dominate consistently over the entire year. C Mitch Morse was the team’s best player; he went through the season without allowing a sack, giving up just 13 total QB pressures over 628 pass-blocking snaps. Mitchell Schwartz didn’t quite live up to his last season in Cleveland, while Eric Fisher on the other side continues his marginal improvement, still exhibiting more issues than you would like as a pass blocker.

15. Chicago Bears (30)

Top overall grade: C Cody Whitehair, 87.2 (No. 6)

Top pass-blocking grade: G Josh Sitton, 91.2 (No. 3)

Top run-blocking grade: C Cody Whitehair, 82.2 (No. 6)

The Chicago Bears still probably can’t believe their luck—they had the league’s best pass-blocking guard land in their lap shortly before the year when Josh Sitton was cut by the Packers. He showed immediately what an upgrade he could be for the team, and in 468 pass-blocking snaps, he surrendered only six QB hurries. Chicago’s interior was arguably the league’s best, with Kyle Long playing well and rookie Cody Whitehair having an excellent debut season at center, having been a college tackle at Kansas State. The offensive tackle combination of Charles Leno Jr. and Bobby Massie was a different story, however, as the pair combined to surrender 73 total QB pressures and 14 penalties all season, with neither grading well in the run game. Tackle is an area for the Bears to focus on in the offseason, because that interior is alreaady excellent.

16. Cleveland Browns (21)

Top overall grade: LT Joe Thomas, 89.1 (No. 4)

Top pass-blocking grade: LT Joe Thomas, 89.9 (No. 5)

Top run-blocking grade: LT Joe Thomas (No. 18), RG John Greco, 80.8 (No. 19)

No offensive line had to deal with as much in terms of the QBs they were blocking for than the Browns, who had rolled through six different passers in seven weeks to begin the season—none of whom demonstrated the kind of playing style that actually makes things easier on his linemen. Despite that, Joe Thomas had another excellent season at LT, and the guard pairing of Joel Bitonio and John Greco also played well. The issue on this line was Cameron Erving, the former first-round pick, playing center in his second season, having struggled massively at guard and tackle as a rookie. He was little, if any, better in the middle, surrendering 30 total QB pressures and being routinely abused as a run blocker. It’s difficult to see much of a future for Erving at this point, and his position is one in need of upgrade.

17. Carolina Panthers (6)

Top overall grade: LG Andrew Norwell, 85.7 (No. 11)

Top pass-blocking grade: LG Andrew Norwell, 85.2 (No. 14)

Top run-blocking grade: LG Andrew Norwell, 84.8 (No. 4)

The loss of Michael Oher doesn’t seem like a huge deal until you consider that it puts Mike Remmers at left tackle, where he was simply out of his depth. Remmers gave up nine sacks and 49 total QB pressures this season, and was also flagged 15 times. Remmers' move also opened up another problem position at right tackle. Daryl Williams wasn’t able to make that spot his own, and RG Trai Turner struggled badly when he was moved out there for three games late in the season. Turner’s season was a huge drop in quality from 2015; he was flagged four times more than last year, surrendering twice the number of sacks and 19 additional QB pressures, while not having nearly the same impact as a run blocker. This is a team that needs an injection of talent at the tackle position, but just getting everybody back in their regular positions likely will help significantly.

18. Houston Texans (11)

Top overall grade: LT Duane Brown, 85.7 (No. 17)

Top pass-blocking grade: C Greg Mancz, 87.2 (tied for No. 3)

Top run-blocking grade: LT Duane Brown, 84.8 (No. 7)

We have reached the point in the list where every remaining O-line is, at best, severely flawed. The Houston Texans' unit saw a mix of excellent performances and pretty terrible ones in the regular season. LT Duane Brown began to creep back towards his best play this season, allowing only one sack all year and run blocked well, with the league’s seventh-best grade in that area, at 84.6. Greg Mancz—a player that dominated PFF's grades in college—looked like a solid find for the team at center in his second season after being an undrafted free agent in 2015. Mancz allowed one sack and 18 total QB pressures across 671 pass-blocking snaps in the regular season, and was perfect in his Wild Card outing against the Raiders last week. Chris Clark, however, was the league’s worst pass-protecting right tackle, surrendering a ridiculous 67 total QB pressures on the season; he was also flagged 13 times. The guard pairing either let themselves down run blocking (Jeff Allen) or pass blocking (Xavier Su’a-Filo) over the year.

19. Detroit Lions (22)

Top overall grade: LT Taylor Decker, 82.8 (No. 23)

Top pass-blocking grade: RG Larry Warford, 82.6 (No. 33)

Top run-blocking grade: RG Larry Warford, 81.8 (No. 16)

The play of rookie LT Taylor Decker was a pleasant surprise for this team. Decker was a player that didn’t overly impress PFF as a draft prospect out of Ohio State, but he was consistently solid all season, performing above-average as both a run blocker and pass protector in his first pro season. Larry Warford was markedly better than a year ago at RG, at least when it comes to run blocking, and Travis Swanson was solid at center. The biggest issue this team had was at LG, where the combination of Graham Glasgow and Laken Tomlinson simply took turns getting abused. As a pair, they surrendered six sacks, 10 penalties, and 49 total pressures, with neither countering that form with dominant run-blocking displays.

20. New York Giants (20)

Top overall grade: LG Justin Pugh, 85.1 (No. 16)

Top pass-blocking grade: C Weston Richburg, 89.3 (No. 17)

Top run-blocking grade: LG Justin Pugh, 84.9 (No. 15)

The Giants may have fielded the worst pair of tackles in the game this season, but the interior trio was solid, particularly when LG Justin Pugh was in the lineup. Ereck Flowers began the season with three solid games, surrendering just five total QB pressures and no hits or sacks over that time, suggesting that he had turned a corner from his ugly rookie season—but then he went in the tank, and was horrendous down the stretch. After the aforementioned three games, he allowed 54 total QB pressures in his final 13 games, with 10 penalties adding to his woes. On the right side, Bobby Hart surrendered 46 total QB pressures himself, and if anything, those numbers flattered his performance; when he was beaten, it tended to be immediately and result in severe pressure.

21. New York Jets (24)

Top overall grade: LG James Carpenter, 83.0 (No. 17)

Top pass-blocking grade: LG James Carpenter, 88.1 (No. 10)

Top run-blocking grade: LG James Carpenter, 76.1 (No. 29)

The one bright spot on this line was the play of LG James Carpenter, who has successfully resurrected his career after bombing out of Seattle as a disaster. He has put together back-to-back solid seasons as a Jet, and this year, was even good as a pass protector for the first time in his career. Carpenter allowed just two sacks and three penalties, and was solid as a run blocker—but that’s about where the good news for this unit ends. Of the other starters, the best play from them was pretty average, with RG Brian Winters (77.1 overall grade) at least holding his own, even if he wasn’t consistently winning his blocks. Both tackle spots were a problem for the team all season, with Ben Ijalana allowing eight sacks on the year and Ryan Clady looking like a shadow of his best play. One game against the hapless 49ers aside, C Wesley Johnson struggled in relief of Nick Mangold, who played just 433 snaps before injury struck.

22. Jacksonville Jaguars (23)

Top overall grade: C Brandon Linder, 87.6 (No. 5)

Top pass-blocking grade: LG Patrick Omameh, 84.6 (No. 19)

Top run-blocking grade: C Brandon Linder, 84.0 (No. 5)

Center Brandon Linder had an excellent season, which is particularly impressive given the play of the rest of the Jaguars' O-line around him. Linder allowed 13 total QB pressures all season, pass blocking on 611 occasions, and was also one of the game’s best run-blocking centers with a PFF grade of 84.0 in that area. The play of Kelvin Beachum was a massive disappointment, given what he has shown in the past. Beachum was poor as both a pass blocker and in the run game, and surrendered 49 total QB pressures on the year. Patrick Omameh showed some solid play—particularly in pass protection—at LG when he was called upon, a notable uptick on his previous displays in 2014 and 2015.

23. Tampa Bay Buccaneers (27)

Top overall grade: RG Ali Marpet, 84.5 (No. 14)

Top pass-blocking grade: RG Ali Marpet, 84.1 (No. 23)

Top run-blocking grade: RG Ali Marpet, 84.4 (No. 5)

The left side of the Buccaneers' line was a real problem area, with the play of LT Donovan Smith proving to be a real issue. Smith surrendered 57 total QB pressures and 14 penalties over his season, with Kevin Pamphile inside of him chipping in with 32 pressures of his own. Second-year player Ali Marpet continued his development with solid play, especially in the run game, while Joe Hawley and Demar Dotson were capable starters at center and right tackle, respectively. The line wasn’t helped when injury forced them to bring Gosder Cherilus into the lineup at right tackle, as he was beaten for three sacks and two hurries in just two games starting before being sent back to the bench to end the year.

24. Denver Broncos (28)

Top overall grade: C Matt Paradis, 90.7 (No. 2)

Top pass-blocking grade: C Matt Paradis, 84.4 (No. 11)

Top run-blocking grade: C Matt Paradis, 90.6 (No. 2)

Matt Paradis took a huge leap forward this season, and was as good as it got at center league-wide. He finished with an overall grade of 90.7 and missed out on PFF’s All-Pro team by a hair, narrowly squeezed out by Alex Mack (Atlanta) and Travis Frederick (Dallas). Paradis was by far the best performer on this line, though, and while the rest of the unit was below-average, right tackle was the Achilles heel over the season, where Donald Stephenson and Ty Sambrailo engaged in a game of one-upmanship to see who could get beat more often. Stephenson finished the season with the lowest overall grade of any offensive lineman, at 28.0, and yet it felt like he was the better option of the two; the only thing saving Sambrailo from earning a lower grade was opportunity.

25. Indianapolis Colts (16)

Top overall grade: LT Anthony Castonzo, 84.2 (No. 20)

Top pass-blocking grade: C Ryan Kelly, 83.1 (No. 12)

Top run-blocking grade: LT Anthony Castonzo, 84.1 (No. 9)

The starting five for the Indianapolis Colts was significantly better than any combination they were forced to field that included backups; unfortunately, bench players were called into action for much of the season. LT Anthony Castonzo had a good season, especially as a run blocker, while rookie C Ryan Kelly had a solid first season in the league, and has yet to allow an NFL sack. Jack Mewhort was decent at LG, but he played in just 10 games, and wasn’t the same player after returning from injury in Week 11. Every other lineman the team was forced to use this season struggled to one degree or another, some having the kind of games that can single-handedly wreck an offensive game plan.

26. Arizona Cardinals (9)

Top overall grade: C A.Q. Shipley, 82.4 (No. 15)

Top pass-blocking grade: LT Jared Veldheer, 80.7 (No. 29)

Top run-blocking grade: RG Evan Mathis, 81.6 (No. 22)

Arizona is another team that owes much of its poor ranking to injury. Evan Mathis played just 199 snaps over the first few weeks of the season before injury forced him to be shut down for the year, opening up a hole on the line. Had the Cardinals been able to play Mathis all season, this line likely would have been solid, but every option the team turned to was worse than the last. D.J. Humphries, Earl Watford, John Wetzel and Ulrick John combined to surrender 22 sacks and 145 total QB pressures covering for essentially two positions on the line, causing the right side to bring a constant deluge of pressure down on QB Carson Palmer for much of the year.

27. Los Angeles Rams (31)

Top overall grade: LG Roger Saffold, 80.7 (No. 26)

Top pass-blocking grade: LG Roger Saffold, 80.7 (No. 40)

Top run-blocking grade: LG Roger Saffold, 78.6 (No. 28)

It’s probably time to give up on Greg Robinson at left tackle. Robinson was flagged 14 times this season, and those penalties didn’t save him from surrendering eight sacks and 40 total QB pressures on 567 pass-blocking snaps. Robinson was also among the worst run-blocking tackles in the league, earning a 36.1 run-blocking grade on the year. Most of the rest of this line were below-average overall, but Roger Saffold actually had a solid season at guard, but for a rough few weeks early in the year. Saffold didn’t allow a sack over the final seven games of the season, and surrendered only one hit in that time, while consistently run blocking well. Rob Havenstein also had a solid year, backing up his rookie season with another capable effort, though his pass blocking dipped from a season ago, and he allowed eight sacks.

28. San Francisco 49ers (26)

Top overall grade: LT Joe Staley, 81.4 (No. 24)

Top pass-blocking grade: RT Trenton Brown, 78.7 (No. 31)

Top run-blocking grade: LT Joe Staley, 82.5 (No. 12)

We are entering the realms of units with almost nothing to point to in terms of positives coming out of the 2016 season. LT Joe Staley was solid, but had his worst season since 2011; pass protection was the facet in which he suffered the biggest drop. Everybody else on the line struggled, with the best performer ending the season with an overall grade of 72.8 (Daniel Kilgore). Carlos Hyde was the team’s leading rusher, but 662 of his 988 rushing yards came after contact, and QB Colin Kaepernick added 337 yards on pass-play scrambles alone, inflating the 49ers' rushing numbers beyond what the line actually gave them with its blocking.

29. Minnesota Vikings (15)

Top overall grade: C Joe Berger, 85.0 (tied for No. 7)

Top pass-blocking grade: C Joe Berger, 87.9 (tied for No. 3)

Top run-blocking grade: C Joe Berger, 80.7 (No. 7)

The Vikings' offensive line became a disaster as the year went on. Matt Kalil had been playing poorly before he went down, but it turns out the drop-off from even that level of play to T.J. Clemmings was precipitous. Clemmings gave up nine sacks, 12 penalties, and 58 total QB pressures between right and left tackle over the year, and in the second half of the season, the Vikings were operating an offense virtually impossible to surrender pressure in, with the league’s lowest average depth of target and one of the faster average times to throw. The play of center Joe Berger saves this unit from being ranked among the very worst in the league, and while Alex Boone didn’t exactly justify his contract, he was solid in his first year with the team.

30. Miami Dolphins (19)

Top overall grade: RT Ja’Wuan James, 78.0 (No. 32)

Top pass-blocking grade: LG Laremy Tunsil, 79.3 (No. 40)

Top run-blocking grade: RT Ja’Wuan James, 81.0 (No. 18)

The loss of Mike Pouncey hurt this team in a major way, and he went down after just 301 snaps of action. Jermon Bushrod was a huge problem at RG all season, allowing five sacks and 34 total QB pressures as a pass blocker. He was also disastrous in the run game, with a 34.9 run-blocking grade, making him the lowest-graded guard league-wide in that facet. Rookie Laremy Tunsil flashed talent throughout the year, but had as many bad games as good ones, and the longer the season wore on, the worse Branden Albert began to look at LT, highlighted by his performance against James Harrison and the Steelers in the Wild Card round of the playoffs.

31. San Diego Chargers (29)

Top overall grade: C Matt Slauson, 81.2 (No. 19)

Top pass-blocking grade: RG D.J. Fluker, 75.9 (No. 50)

Top run-blocking grade: C Matt Slauson, 76.7 (No. 10)

Spare a thought for Philip Rivers, who has to watch the other two big QBs from the 2004 draft class steering playoff-bound teams and contending for a championship while he deals with one of the worst offensive lines in the game. Center Matt Slauson was the best part of this offensive line, and his play was average, at best. This line couldn’t pass protect, surrendering 238 total QB pressures for the second-lowest pass-blocking efficiency mark in the league, and its run blocking was no better. Of 1,510 rushing yards as a team, 906 of them came after contact, with the line generating an average of just 1.5 yards before contact per carry.

32. Seattle Seahawks (32)

Top overall grade: C Justin Britt, 80.5 (No. 16)

Top pass-blocking grade: C Justin Britt, 79.1 (No. 21)

Top run-blocking grade: C Justin Britt, 71.9 (No. 18)

Nobody has invested less in their offensive line than the Seattle Seahawks, and it showed in their performance over the 2016 season, with the unit being directly responsible for some of the team's losses. Even their best performer, Justin Britt, was moved to center in a last-ditch attempt to salvage his career, rather than have to invest more in the position (though he has played far better at center than any other position, surrendering no sacks or hits this season). The other four starters top out at overall grades of 52.3, and the best-ranked among them (LG Mark Glowinski) is the 63rd-ranked player at his position league-wide. The success Seattle has experienced this season is entirely in spite of its offensive line, and requires QB Russell Wilson and the running backs to play stellar football to continue to overcome the unit's deficiencies.

[Editor's note: To see PFF's preseason offensive line rankings for the 2016 season, click here.]