With a quarter of the 2016 season in the books for most NFL teams, it's time to dive into our first in-season offensive line rankings of the year. During this process, we took into account the grades of every player that has taken snaps for each team along the line this season, and the starters have been listed according to which players have taken the most snaps at each position (unless a player has subsequently been lost for the season due to injury, or a clear starter has returned from injury).

Next to each team, please note that unit's preseason offensive line ranking:

1. Tennessee Titans (25)

Starters: LT Taylor Lewan, LG Quinton Spain, C Ben Jones, RG Josh Kline, RT Jack Conklin

You wouldn’t know it from their record, but the Titans all of a sudden have the game’s best O-line through the first four weeks of the season. Taylor Lewan and Jack Conklin both rank among the top five OTs league-wide, with Lewan sitting atop the PFF offensive tackle rankings with a grade of 90.8. The other positions haven’t played quite as well, but there has been no single weak link along the line, with every player performing at least at an average level once Chance Warmack went down.

2. Green Bay Packers (3)

Starters: LT David Bakhtiari, LG Lane Taylor, C J.C. Tretter, RG T.J. Lang, RT Bryan Bulaga

Another team with no real weak link along the line, the Packers have had all five starters playing well, especially when it comes to pass protection. The Packers' line has allowed just 17 total pressures on the season, the best mark in the league (albeit across only three games). They have the second-best pass-blocking efficiency score, trailing only New Orleans, despite Aaron Rodgers ranking among the bottom half of QBs when it comes to the average time it takes to get rid of the football.

3. New York Giants (20)

Starters: LT Ereck Flowers, LG Justin Pugh, C Weston Richburg, RG John Jerry, RT Marshall Newhouse

There may be no bigger turnaround in performance from a season ago than that of Giants LT Ereck Flowers, who was disastrous as a rookie while struggling through an injury all year. In 2016, however, he has been impressive, allowing no sacks through four games and run blocking extremely well. Justin Pugh has become an All-Pro level guard, and currently leads the rankings at PFF with a 90.4 grade. The worst performer so far has been C Weston Richburg, but even he has been good as a pass blocker, allowing just a single total pressure (a sack); his run blocking, however, has left something to be desired (42.8 run-blocking grade).

4. Washington Redskins (12)

Starters: LT Trent Williams, LG Shawn Lauvao, C Spencer Long, RG Brandon Scherff, RT Morgan Moses

Washington has had some injuries to contend with along an O-line that even saw them shuffle LT Trent Williams in to play guard mid-game, where he still preformed well. Williams has been back to his best at tackle, while Morgan Moses on the other side and RG Brandon Scherff have also played well. The other two spots have been less accomplished and in flux due to injuries, which is something that could hamper them over the season, but through four weeks, this has been one of the better units in the league.

5. Dallas Cowboys (1)

Starters: LT Tyron Smith, LG Ronald Leary, C Travis Frederick, RG Zack Martin, RT Doug Free

Tyron Smith has been injured, and LG La’El Collins has been lost for an extended period, so the line hasn’t been quite as dominant as we expected it to be coming into the year. Collins, in particular, was not playing well even before he got hurt, but Travis Frederick at center and Zack Martin at G remain dominant players and appear to be just hitting their best form. Smith’s return at LT should make a big impact on this line if he comes back 100 percent healthy.

6. Denver Broncos (28)

Starters: LT Russell Okung, LG Max Garcia, C Matt Paradis, RG Michael Schofield, RT Donald Stephenson

Maybe the surprise O-line of the season—if that title doesn’t already belong to the Giants—the Broncos have seen massively-improved play across several spots. Matt Paradis has been the best center in the game so far this season, and the only poor performances have come from when they needed to go to the bench and start players like Ty Sambrailo, who has allowed seven total pressures in only 84 pass-blocking snaps. The Broncos' offensive line has been a big reason for the relative success of QB Trevor Siemian and RB C.J. Anderson.

7. Oakland Raiders (2)

Starters: LT Donald Penn, LG Kelechi Osemele, C Rodney Hudson, RG Gabe Jackson, RT Menelik Watson

Injuries have really struck the Raiders at right tackle this season, causing them to play five different players there in just four games. Kelechi Osemele has proven to be worth the big-money investment in free agency, and has been a dominant run blocker, while also showing his versatility with the ability to kick out to tackle when injuries hit. Donald Penn continues to play some of the best football late into his career, and Rodney Hudson has been solid at center. Gabe Jackson has been relatively disappointing so far on the right side, having moved from left guard over the offseason.

8. Atlanta Falcons (5)

Starters: LT Jake Matthews, LG Andy Levitre, C Alex Mack, RG Chris Chester, RT Ryan Schraeder

The Falcons have had an impressive offensive line with one weak link in the form of RG Chris Chester. Chester has not graded well as a run blocker and has allowed two sacks, a hit, and six hurries as a pass protector, which is the fifth-most among guards. The rest of the unit has been good, and Alex Mack looks to be another good free-agent O-line success, playing something like his best football again. The improvement we saw from both tackles last season looks to have been no fluke.

9. New Orleans Saints (8)

Starters: LT Terron Armstead, LG Andrus Peat, C Max Unger, RG Jahri Evans, RT Zach Strief

Had Terron Armstead not missed time with injury, this line might have been ranked higher, but Andrus Peat at LT was a disaster against Atlanta trying to block Dwight Freeney, though he was far better the next week against San Diego. Peat and RG Jahri Evans have been the relative weak points along the line, but the other spots have quality starters playing well when they are on the field. The Saints have the league’s best pass-blocking efficiency score, at 87.8.

10. Philadelphia Eagles (7)

Starters: LT Jason Peters, LG Allen Barbre, C Jason Kelce, RG Brandon Brooks, RT Lane Johnson

The threat of suspension continues to hang over Lane Johnson, but he's been on the field thus far and has impressed at RT, allowing only three total pressures and no sacks or hits on QB Carson Wentz. Ironically, it is the old stalwarts of this line—Jason Peters at LT and Jason Kelce at C—that have been the poorest performers through four weeks, with Kelce in particular struggling in the middle. Allen Barbre and Brandon Brooks at guard have been very good, allowing the team a far greater platform to run the ball than a year ago.

11. Cleveland Browns (21)

Starters: LT Joe Thomas, LG Joel Bitonio, C Cameron Erving, RG John Greco, RT Austin Pasztor

Three-fifths of this line has been solid and ever-present, but the other two spots have been problematic, either through injury or poor play. Cameron Erving was poor at center before being hurt, and the Browns haven’t been able to lock down a suitable replacement, losing one of the players (Austin Reiter) given the chance to stand in his stead. Pasztor has only surrendered one sack, but has been flagged five times and allowed 16 total pressures, fifth-most among OTs in the league.

12. Pittsburgh Steelers (14)

Starters: LT Alejandro Villanueva, LG Ramon Foster, C Maurkice Pouncey, RG David DeCastro, RT Marcus Gilbert

Alejandro Villanueva has developed somewhat at LT, but remains a below-average starter at the position and has allowed 18 total pressures this season, fourth-most among OTs. The rest of the line has been solid, if unspectacular. RG David DeCastro has allowed three sacks and 12 total pressures, second-most among guards, but has been able to counter that with some good run blocking. Only Ramon Foster has not given up a sack yet among the Steelers' starters.

13. Chicago Bears (30)

Starters: Charles Leno Jr., LG Josh Sitton, C Cody Whitehair, RG Kyle Long, RT Bobby Massie

The acquisition of Josh Sitton has given the Bears one of the best interior trios in the game, if not the best. It’s a shame about the tackles, though—in particular Bobby Massie at RT, who has been terrible. Massie has shown in the past the ability to play far better when he wants to, but he has now allowed 19 total pressures and three sacks, second-most in the league, and has the second-worst pass blocking efficiency mark among OTs. Rookie Cody Whitehair has played well at center, anchoring the two quality guards.

14. Jacksonville Jaguars (23)

Starters: LT Kelvin Beachum, LG Patrick Omameh, C Brandon Linder, RG A.J. Cann, RT Jermey Parnell

The Jaguars' offensive line has been solid this season, especially when LT Kelvin Beachum has been healthy. Luke Joeckel (now headed to IR with a knee injury) has been better inside at guard, though curiously still unable to pass protect well, surrendering a hit and six hurries inside where he should have less space to defend. C Brandon Linder has been one of the better players in the league at his position, allowing just two total pressures so far and sitting fourth among PFF's center rankings with a grade of 82.5.

15. Detroit Lions (22)

Starters: LT Taylor Decker, LG Laken Tomlinson, C Travis Swanson, RG Larry Warford, RT Riley Reiff

Rookie Taylor Decker has been okay at tackle so far this season, allowing three sacks and 13 total pressures while being asked to pass block 187 times already. The weak link so far has been G Laken Tomlinson, whose run blocking has been poor, but he's actually been solid in pass protection—which has been more important for a team passing far more than they are running. Riley Reiff has been performing well as a run blocker, but has been only average in pass protection.

16. Baltimore Ravens (13)

Starters: LT Ronnie Stanley, LG Alex Lewis, C Jeremy Zuttah, RG Marshal Yanda, RT Ricky Wagner

Not quite matching his preseason play, rookie LT Ronnie Stanley has at least been average through four weeks, which is an achievement for a rookie tackle. Marshal Yanda remains the best guard in the game, and has been among the top performers at the position this year, currently trailing only Justin Pugh and Zack Martin with an 87.1 overall grade. Ricky Wagner has bounced back after an awful 2015 season, but the rest of the players to see time have been average, at best.

17. Cincinnati Bengals (4)

Starters: LT Andrew Whitworth, LG Clint Boling, C Russell Bodine, RG Kevin Zeitler, RT Cedric Ogbuehi

Coming into the season, the Bengals had two question marks along the line in C Russell Bodine and RT Cedric Ogbuehi. So far, both of those players have performed below-average, combining to surrender 20 total pressures. Andrew Whitworth at LT remains one of the league’s better tackles, and has allowed only three pressures in 168 pass-blocking snaps. The guard pairing has been solid, but perhaps a little below what we have come to expect from them so far.

18. Arizona Cardinals (9)

Starters: LT Jared Veldheer, LG Mike Iupati, C A.Q. Shipley, RG Evan Mathis, RT D.J. Humphries

The Cardinals' O-line is better with a healthy Evan Mathis in the lineup, but he has missed time hurt this year and has been a little under full fitness when actually on the field. Returning to face Aaron Donald certainly didn't help, either. Mike Iupati has been the unit’s best performer, moving people around in the run game as you would expect, but allowing no hits or sacks across 192 pass-blocking snaps. D.J. Humphries has allowed four sacks and 12 total pressures, and has been a relative weak link when pass blocking at RT, but has not been disastrous overall.

19. New York Jets (24)

Starters: LT Ryan Clady, LG James Carpenter, C Nick Mangold, RG Brian Winters, RT Brent Qvale/Ben Ijalana

The Jets have effectively rotated starters at RT, with Ben Ijalana being the better-performing player of the pair. Only two run-blocking snaps and eight pass-blocking snaps separates him and Brent Qvale through four weeks, but Ijalana has allowed just five total pressures to Qvale’s nine, and he has yet to be flagged, while Qvale has one penalty to his name. James Carpenter continues to be a far better player in New York than he ever was in Seattle, while Nick Mangold has been nearly perfect in pass protection in the middle.

20. Buffalo Bills (10)

Starters: LT Cordy Glenn, LG Richie Incognito, C Eric Wood, RG John Miller, RT Jordan Mills

The Bills' line has been impressively average across the board. RT Jordan Mills probably strays the furthest from average when it comes to his run blocking, but he has actually been relatively solid as a pass blocker to balance that, allowing only six total pressures and no sacks or hits yet this year. Strangely, only LG Richie Incognito has actually surrendered a sack amongst the starters, and he has coughed up three on his own.

21. Carolina Panthers (6)

Starters: LT Michael Oher, LG Andrew Norwell, C Ryan Kalil, RG Trai Turner, RT Mike Remmers

Mike Remmers at RT has actually been fine any time he hasn’t had to face a good pass-rusher. When he comes up against a high caliber talent, though, it’s a disaster; he has surrendered 19 total pressures this season, 12 of which came in two games. Guards Andrew Norwell and Trai Turner have been solid, but perhaps not as good as we expected them to be coming off last season, while Michael Oher remains a below-average player, at best, at LT.

22. Indianapolis Colts (16)

Starters: LT Anthony Castonzo, LG Jack Mewhort, C Ryan Kelly, RG Denzelle Good, RT Joe Reitz

The Colts' line is surrendering a huge volume of pressure, with Andrew Luck feeling heat on 41.8 percent of his dropbacks—the highest rate in the league—but it isn’t all on the line. Luck holds the ball, on average, longer than all but one other QB in the league, and the line actually has a couple of solid performers. LT Anthony Castonzo has been good, ranking 14th in the PFF's OT grades with a mark of 81.5, while G Jack Mewhort (82.6) ranks 10th among guards. Injuries have seen some ugly performances from depth players, but the starting five is better than the stats indicate.

23. Miami Dolphins (19)

Starters: LT Branden Albert, LG Laremy Tunsil, C Anthony Steen, RG Jermon Bushrod, RT Ja’Wuan James

Only C Anthony Steen has avoided giving up a sack so far among the starting five, and he may soon be sent to the bench with the return of Mike Pouncey. Rookie Laremy Tunsil has been average at best, allowing a sack, three hits, and seven hurries across his 160 pass-blocking snaps. Tunsil got a chance to play a game at left tackle with the injury to Branden Albert, but ironically, that was his worst performance of the season, struggling against the Cincinnati Bengals and giving up four of his 11 total pressures on the year.

24. New England Patriots (18)

Starters: LT Nate Solder, LG Joe Thuney, C David Andrews, RG Shaq Mason, RT Marcus Cannon

The return of long-time line coach Dante Scarnecchia has at least got this unit moving in the right direction, albeit slowly. Rookie Joe Thuney has appeared full of potential, especially in the run game, where he has been able to move bodies with excellent power. Nate Solder has been solid at left tackle, allowing just four total pressures in 95 pass-blocking snaps, with injury causing him to miss time. The other positions are less impressive, with Marcus Cannon at RT, David Andrews at C, and Shaquille Mason at RG proving to be average, at best.

25. Kansas City Chiefs (17)

Starters: LT Eric Fisher, LG Zach Fulton, C Mitch Morse, RG Laurent Duvernay-Tardiff, RT Mitchell Schwartz

Many of the O-lines in the bottom half of this list have been forced to go to the bench due to injuries, highlighting the league-wide depth issue with offensive linemen. The Chiefs have used eight offensive linemen so far this year, and all eight have at least 63 snaps—or a solid game’s worth—to their name. Mitchell Schwartz has been solid at right tackle, though he has been beaten for five sacks already, while Eric Fisher’s rise seems to have topped out at “okay.” The interior has been an issue, with Mitch Morse in particular struggling in the run game, currently ranked as the 31st center in terms of overall grade.

26. Tampa Bay Buccaneers (27)

Starters: LT Donovan Smith, LG Kevin Pamphile, C Joe Hawley, RG Ali Marpet, RT Demar Dotson

The Bucs have actually been pretty fortunate with injuries, and have three players that have yet to miss a snap, another in C Joe Hawley that has missed just two, and Kevin Pamphile missing only 14 over the season. They just haven’t been very good, despite being consistently present as a group. Combined, they have surrendered 60 total pressures through four games, the second-most in the league behind only Indianapolis. That puts them on pace for a ridiculous 240 over the season—34 more than the lowest figure among teams that have played four games.

27. San Diego Chargers (29)

Starters: LT King Dunlap, LG Orlando Franklin, C Matt Slauson, RG D.J. Fluker, RT Joe Barksdale

San Diego’s offensive line may be better than a year ago, but it’s still not very good. Matt Slauson has been an upgrade at center and has allowed just four total pressures, with no sacks or hits, but the rest of the group has been poor in pass protection, putting a lot of pressure on Philip Rivers to perform despite less-than-ideal pockets. As a group, the Chargers' run blocking has been better, but RB Melvin Gordon still has to do too much by himself, gaining 164 of his 230 yards this season after contact, breaking eight tackles along the way to do so.

28. San Francisco 49ers (26)

Starters: LT Joe Staley, LG Zane Beadles, C Daniel Kilgore, RG Andrew Tiller, RT Trenton Brown

LT Joe Staley remains the one bright spot on a line that was once the best in the league back in 2012. Even Staley has been less impressive this season, though, allowing no sacks but nine total pressures, and seeing a dip in his overall performance. He is by far the class of the 49ers' unit, though, that features various shades of poor play. Trenton Brown has been perhaps the worst performer, with awful run blocking explaining to large degree why the team has averaged just 2.9 yards per carry on runs off right tackle.

29. Houston Texans (11)

Starters: LT Chris Clark, LG Xavier Su’a-Filo, C Greg Mancz, RG Jeff Allen, RT Derek Newton

Another team that can still remember when they were the best line in the league, the Texans are far from that now. Chris Clark has struggled to fill in for LT Duane Brown, and has surrendered two sacks, two hits, and six hurries in 160 pass-blocking snaps, while Derek Newton on the other side has been even worse, matching him in sacks and hits, but adding four more hurries. Newton has been the one member of the line to grade well as a run blocker, with all of the rest struggling badly in that area.

30. Minnesota Vikings (15)

Starters: LT T.J. Clemmings, LG Alex Boone, C Joe Berger, RG Brandon Fusco, RT Andre Smith Jr.

Minnesota’s offensive tackles have been a huge issue, and if anything, the problem only got worse with the loss of Matt Kalil, putting T.J. Clemmings into the lineup. C Joe Berger has been the line’s best performer once again, but has been shy of his 2015 form. Run blocking has been poor; the team doesn’t have a single runner averaging more than 3.7 yards per carry, and the majority of those yards came on runs that made it around the edge of the line, rather than through holes opened up by it. Backup Jeremiah Sirles showed relatively well in limited snaps filling in, and could be a potential upgrade if they made the switch, particularly at RT.

31. Los Angeles Rams (31)

Starters: LT Greg Robinson, LG Roger Saffold, C Tim Barnes, RG Cody Wichmann, RT Rob Havenstein

The Rams are winning games, but it’s certainly not thanks to their offensive line, which has been playing poorly. LT Greg Robinson can probably safely be labeled a bust at this point, and has allowed 14 total pressures this season. He is currently the 75th-ranked OT at PFF, with a grade of 35.4. Rob Havenstein may be the best of the group this season, and his overall grade is just 72.1, with three of the five Rams' O-line members grading lower than 53.0. RB Todd Gurley has gained just 2.6 yards per carry, and 193 of his 217 rushing yards have come after contact, meaning, on average, the blocking has gained him 0.3 yards before being hit, or just under a foot per rush.

32. Seattle Seahawks (32)

Starters: LT Bradley Sowell, LG Mark Glowinski, C Justin Britt, RG Germain Ifedi, RT Garry Gilliam

The Seahawks had the worst line in the league on paper heading into the season, and it has proved to be just that through four weeks. Seattle will be hoping the return of rookie Germain Ifedi can improve matters, but in 60 snaps so far, he hasn’t suggested he will be much of an upgrade. Justin Britt has been a relative bright spot at center, with a very strong game against the Jets after three more average performances, but the rest of the starters have been poor. Bradley Sowell and J’Marcus Webb, in particular, have just reinforced why they were given up on as starting propositions by previous teams, while Garry Gilliam at RT has been struggling, especially against the Rams. The Seahawks' offense is hamstrung by the lack of investment in the line.