Discussions to determine the best and worst offensive lines in the NFL are about as clear and convincing as the statistics that accurately reflect the effectiveness of this important unit.

Exactly. There is no such stat.

Oh, there are imaginative equations that include quarterback drop-backs, coverage sacks, down-and-distance and number of pass plays called on a rainy day. Well, we're kidding about the rainy day part, but the point remains, stats don't tell the story for most O-lines except for some extreme cases -- the very, very good or bad. That is because there are too many "yeah-buts" attached to most statistics used to measure offensive lines.

Sacks yielded per drop-back or yards per rush are often referenced in an attempt to quantify the work of offensive linemen.

A team with numerous sacks might point to contributing factors: receivers who can't get open, quarterbacks (especially inexperienced ones) who hold onto the ball too long or go through their progression of reads too slowly. ... and, conversely, a low number of sacks may not say much about the front wall if the quarterback is named Dan Marino or Peyton Manning, two of the quickest triggers in NFL history.

And yards per carry can be skewed by the breakaway talents of a gifted back who gains yards despite the inability of his offensive line.

Classic chicken-and-egg stuff.

Regardless, reporters covering each team for The Sports Xchange were asked to analyze offensive lines. The results are presented here team-by-team to be combined with whatever stat or stats readers prefer in an attempt to give some rank and order to the subject.

Generally speaking, which is a copout way to avoid the truthful IMO, Dallas, San Francisco, New England and Philadelphia have good offensive lines and Denver may or may not depending on how much weight is placed on the Manning factor. Seattle, the Super Bowl champion, is among the worst two or three in the league.

And that sad ranking of the Seahawks' line makes running back Marshawn Lynch and Beast Mode all the more impressive. And can't you just hear those intense 12th-man fans from Seattle objecting to such a low ranking, with a "yeah, but two key linemen were injured most of last season." And so it goes.

Here is analysis from TSX reporters on each team's offensive line for fans to mix and match with whatever statistics they deem appropriate. Teams are listed alphabetically, which may be the only inarguable way to rank offensive lines:

ARIZONA CARDINALS

--OFFENSIVE LINEMEN: Starters - LT Jared Veldheer, LG Jonathan Cooper, C Lyle Sendlein, RG Paul Fanaika, RT Bobby Massie. Backups - G/T Nate Potter, G Earl Watford, T Bradley Sowell, G/C Ted Larsen, G/C Anthony Steen, C Philip Black.

There will be at least three new starters and possibly four. Left tackle has been a need for years, and the Cardinals signed Veldheer in free agency. They think he can be elite. Cooper, the seventh overall pick in 2013, didn't play as a rookie after suffering a broken leg. He wasn't 100 percent in offseason practices, but coaches think he will be by the start of training camp. Sendlein is a smart, solid veteran who holds the unit together. Fanaika is being challenged by Earl Watford. No matter who wins the job, the position will be a weakness until someone proves otherwise. Massie emerged from the offseason as the starter, but his hold on the job is tenuous. He's being challenged by Sowell and Potter, and the Cardinals have also looked outside for help. They worked out Tyson Clabo in June and re-signing Eric Winston, last year's starter, remains a possibility.

ATLANTA FALCONS

--OFFENSIVE LINEMEN: Starters - LT Sam Baker, LG Justin Blalock, C Joe Hawley, RG Jon Asamoah, RT Jake Matthews. Backups - TLamar Holmes, T Ryan Schraeder, T Terren Jones, C Peter Konz, C James Stone, G Mike Johnson, G Gabe Carimi, G Adam Replogle, G Harland Gunn.

The Falcons mis-assessed the readiness of Konz and Holmes to take over for Todd McClure and Tyson Clabo last season. Coupled with weak play by right guard Garrett Reynolds, who was released, and retread tackle Jeremy Trueblood and the Falcons were leaking oil before most games started. The unit gave up 44 sacks and couldn't open up any holes in the run game as the Falcons were last in the league in rushing at 77.9 yards per game. Asamoah was added in free agency and Matthews was selected sixth overall in the draft. The Falcons are hoping that Baker (knee surgery) can return to good health. New position coach Mike Tice will try to whip the unit into shape.

BALTIMORE RAVENS

--OFFENSIVE LINEMEN: Starters -- LT Eugene Monroe, LG Kelechi Osemele, C Jeremy Zuttah, RG Marshal Yanda, RT Rick Wagner. Backups -- LT James Hurst, LT David Mims, LG John Urschel, C Gino Gradkowski, C Reggie Stephens, RG A.Q. Shipley, RG Will Rackley, RT Ryan Jensen, RT Jah Reid, RT Parker Graham, RT Brett Van Sloten.

The Ravens re-signed Monroe as the cornerstone of their line to a $37.5 million contract. Osemele looked good during the spring after undergoing back surgery last fall. Zuttah should be an upgrade at center after arriving via an offseason trade. Yanda is the lone Pro-Bowl selection and is the mainstay of the line. Wagner is the biggest question mark as a first-time starter at right tackle. Gradkowski is the primary backup inside after starting every game at center last season.

BUFFALO BILLS

--OFFENSIVE LINEMEN: Starters -- LT Cordy Glenn, LG Chris Williams, C Eric Wood, RG Kraig Urbik, RT Erik Pears. Backups - G Doug Legursky, T Cyrus Koundjio, OL Antoine McClain, T Chris Hairston, G J.J. 'Unga, G Mark Asper, G Cyril Richardson, T Seantrel Henderson, OL Edawn Coughman, C Macky MacPherson.

The emphasis for the Bills up front was to get big, athletic men, and that's what they did in the draft by choosing Kouandjio, Richardson and Henderson. Taking all 15 men into account, they now have the heaviest line in the NFL. Williams was a free-agent signing, but he really hasn't distinguished himself in the NFL. Glenn and Wood are excellent, and Urbik is a grunt who quietly gets the job done. The big battle will be at right tackle where Kouandjio was drafted to replace Pears. However, he still has to beat out the veteran. The battle for backup spots will be hot, and it's tough to tell who will emerge, but if Henderson can impress, the Bills - based on his potential - might have to keep him. There's a chance Pears will get cut, so that would open up a backup tackle spot.

CAROLINA PANTHERS

--OFFENSIVE LINEMEN: Starters - LT Nate Chandler, LG Amini Silatolu, C Ryan Kalil, RG Trai Turner, RT Byron Bell. Backups - C Brian Folkerts, C Jared Wheeler, G Derek Dennis, G Edmund Kugbila, G Andrew Norwell, G Chris Scott, T David Foucault, T Kevin Hughes, T Oscar Johnson, T Andrew McDonald, T Garry Williams.

The departure of former franchise left tackle Jordan Gross created a void that will be hard to fill. Chandler and Bell will continue their battle in camp, but whoever wins the job will take his lumps. Kalil is as rock solid as they come at center. Turner, who turned 21 in June, played with the ones in offseason workouts, and it is hard to see him giving the job up. Silatolu is coming off ACL surgery, but the team believes he can get back to the form that saw him improving early in 2013. Depth here is not good.

CHICAGO BEARS

--OFFENSIVE LINEMEN: Starters - LT Jermon Bushrod, LG Matt Slauson, C Roberto Garza, RG Kyle Long, RT Jordan Mills. Backups - G/T James Brown, G/T Eben Britton, C Brian de la Puente, C Taylor Boggs, G James Dunbar, G Ryan Groy, T Cody Booth, T Charles Leno Jr., T Joe Long, T Michael Ola.

Only Mills last year displayed a big need for improvement, as one of the least effective pass blockers at tackle in the NFL according to the stat geeks at profootballfocus.com. Still, he was light years ahead of past tackles. Bushrod proved to some skeptics that he was an effective left tackle after coming over from New Orleans. Slauson was good enough at guard to warrant a new contract and Long made the Pro Bowl, albeit as a reserve. Garza is 35 and the unquestioned leader of the line. It would seem that signing de la Puente gave them an insurance policy in case age catches up with him. Garza never has been a standout short-yardage blocker, but is dependable to very good in the regular running game and in pass blocking.

This line has more depth than some other recent Bears lines, as de la Puente, Brown and Britton all have played before. Britton, Ola and Leno Jr. could be challengers for Mills if he slips. Overall a weak short-yardage and goal-line blocking group that needs to become more consistent in the running game. Much improved as pass blockers, but the scheme also allows for shorter pass drops and helps them here.

CINCINNATI BENGALS

--OFFENSIVE LINEMEN: Starters - LT Andrew Whitworth, LG Clint Boling, C Mike Pollak, RG Kevin Zeitler, RT Andre Smith. Backups - C Russell Bodine, C Trevor Robinson, C T.J. Johnson, T Marshall Newhouse, T/G Dan France, T Curtis Feigt, G Tanner Hawkinson, G Trey Hopkins, T Will Svitek, G Chandler Burden.

The tackles and right guard are set with Whitworth, Smith and Zeitler holding down starting spots. Beyond that, the interior positions get interesting. Boling (ACL) and Pollak (knee) are both recovering from injuries. They hope to be back for training camp, but it is yet to be seen when they could actually contribute. A challenger at center, now without released starter Kyle Cook, is fourth-round pick Russell Bodine. He's powerful and nasty, but had trouble snapping the ball during OTAs. It would be nervous time if he started Week 1 across from Haloti Ngata. The versatile Tanner Hawkinson and undrafted free agent Trey Hopkins have a good chance to latch onto the back end of the roster.

CLEVELAND BROWNS

--OFFENSIVE LINEMEN: Starters - LT Joe Thomas, LG Joel Bitonio, C Alex Mack, RG John Greco, RT Mitchell Schwartz. Backups - G Garrett Gilkey, G Jason Pinkston, G/T Paul McQuistan, T Reid Fragel, T Jeremiah Warren, G Chris Faulk, T Keavon Milton, T Randall Harris, C Alex Parsons, T Martin Wallace.

Shanahan is a big believer in zone blocking. The Browns' offensive line is built with athletic players more than bulldozers, which is a reason general manager Ray Farmer used the 35th pick on Bitonio. Thomas is in his eighth season. Mack is in his sixth and though he has been to the Pro Bowl twice he has yet to play on a winning team. Pettine is his fourth head coach. The Browns have depth on the offensive line, particularly inside with McQuistan and Gilkey. One year ago, the Browns scored four rushing touchdowns. That number should increase greatly with better running backs and better blocking.

DALLAS COWBOYS

--OFFENSIVE LINEMEN: Starters - LT Tyron Smith, LG Ron Leary, C Travis Frederick, RG Zack Martin, RT Doug Free. Backups - G Mackenzy Bernadeau, G Brian Clarke, G Andre Cureton, G Tyronne Green, G Ronald Patrick, G Uche Nwaneri, T Josh Aladenoye, T Darius Morris, T Jermey Parnell, T John Wetzel.

The Cowboys want to win as they did in the 1990s when they were led by a dominant offensive line. They continued on that path in the draft with the selection of Martin with the 16th overall pick. He is the third first-round pick to be used on an offensive lineman in the last four years, joining tackle Tyron Smith in 2011 and center Travis Frederick in 2013. Smith is the anchor of the unit and is coming off his first Pro Bowl and he is still only 23.

Frederick was a walk-in starter and immediately became one of the best in the league. Look for Martin to start out at right guard before replacing Free at right tackle in 2015. Free had a bounce-back season at tackle in 2013 after being forced to take pay cut to keep his job, but he is in the last year of his contract. The only battle in camp will be at left guard where Leary, last year's starter, will compete with Bernadeau and former Jacksonville Jaguars starter Nwaneri for the starting job.