They seldom make the highlight packages. If you hear their name during a game, it's usually because they've done something wrong. Yet they are the often overlooked element when it comes to the success or failure of NFL teams.
They are the offensive linemen, and although they're always essential, it's this time of the season when they can really create separation. As the weather turns colder, wetter and windier, teams frequently run the ball more, relying on their big men up front to set the tone and push open holes.
It's tricky to judge the effectiveness of an offensive line based solely on simple statistics such as sacks, yards per carry, rushing touchdowns and the like. There are so many factors and complexities — among them: What was the quarterback's role in that sack? Did a back miss his block? Who's carrying the ball? How good is the opposing defense at stopping the run? Several websites do a good job of drilling down on the stats, looking deeper into the numbers to assign a pecking order to the league's 32 offensive lines, but it's a nuanced science.
"In the end, the film is the most important thing," said former NFL offensive lineman Geoff Schwartz, whose brother, Mitchell, plays right tackle for Kansas City. "You can use stats to confirm what you see on film, but it starts with the film."
For the purposes of ranking the NFL's top five and bottom five offensive lines heading into the second half of the regular season, I turned to a trio of experts: Schwartz and offensive line consultant Duke Manyweather, who co-host the "Block Em' Up" podcast; and Hall of Fame tackle Jackie Slater, who played his entire 20-year career with the Rams and now coaches offensive line at Azusa Pacific.
"It's hard to assess offensive lines," Manyweather said. "There are people who get it and people who don't. A lot of people may not want to admit this, but even teams get it wrong a lot."
Now, a look at the five lines playing the best as of Week 10:
1. Philadelphia — When nine-time Pro Bowl left tackle Jason Peters went down with a season-ending knee injury last month, some observers saw it as the beginning of the end for the Eagles. That did not come to pass. At 8-1, Philadelphia has the best record in the league, and the cohesiveness of the offensive line has a lot to do with that. Slater's stance: "You can't overlook the play-calling and the decision-making of a talented young quarterback in Carson Wentz."
2. New Orleans — The Saints have surrendered a league-low eight sacks, which is particularly impressive considering how much Drew Brees throws the ball. The left side of the line is particularly strong with Terron Armstead at tackle and Andrus Peat at guard, and rookie Ryan Ramczyk has found a home at right tackle. Slater's stance: "Getting Armstead back was huge, and Brees is such a quick trigger man that it always helps the line."
3. Dallas — The Cowboys have been the gold standard in terms of offensive line play the past few seasons, and they're seeing a lot of eight-man boxes with defenses selling out to stop Ezekiel Elliott. With that back now suspended for six games, we'll get a better idea of how much of that running game is him, and how much is the line. Slater's stance: "Every bit of success Jerry Jones has had as an owner is partly due to his investment in his offensive line."
4. Rams — In one year, the Rams have gone from having the NFL's worst line to one of its best. The addition of left tackle Andrew Whitworth was huge — Manyweather calls him the team's most valuable offensive player so far — and getting center John Sullivan was big too. But the whole line is rolling, and Jared Goff and Todd Gurley are surely grateful. Slater's stance: "The stability in this unit, including putting young lineman Rob Havenstein back at right tackle, has been critical."
5. Pittsburgh — It's a blast from the past with the Steelers dominating up front again, as they have on so many of their championship teams. This line is especially solid in the interior, with guards David DeCastro and Ramon Foster, and center Maurkice Pouncey. Slater's stance: "Mike Munchak is coaching that offensive line, and if anyone is going to put together the best interior triad it's that Hall of Famer."
Best of the rest — Washington would be a top-five line but for some key injuries. … Oakland was right up there with Dallas as the league's best last season, but the Raiders have taken a slight step backward with their scheme adjustments. … Jacksonville, Minnesota and Tennessee could all make convincing cases to be among the top five.
Here are the bottom five at this point, starting with the worst:
1. New York Giants — The one-win Giants have had a terrible season on both sides of the ball, but their offensive line has been particularly bad. Their tackles have been terrible both in pass protection and in run blocking, where they're 27th in rushing. Slater's stance: "The grit of this team went to Jacksonville with Tom Coughlin. The Giants should try rookie Chad Wheeler at left tackle because he could be their future."
2. Cincinnati — The Bengals sorely miss Whitworth and guard Kevin Zeitler, now in Cleveland. They're averaging a paltry 3.1 yards per carry, worse than everyone but Arizona (3.0). Slater's stance: "Cincinnati's loss was the Rams' gain. The Bengals should never have let Andrew Whitworth go."
3. Colts — The Colts have surrendered an NFL-high 38 sacks. Three of their starting linemen from Week 1 are on injured reserve. Compounding their talent issue up front is the fact that those guys are blocking for an indecisive young quarterback who holds onto the ball for too long. Slater's stance: "I was on the field for warmups when the Colts played the Rams. This is a hodgepodge group of offensive linemen, and some of them don't look the part."
4. Broncos — Right tackle Menelik Watson has been a bust as a free-agent acquisition so far, and now he's out for the season with a foot injury. Rookie Garett Bolles, while showing toughness and a mean streak, leads the team in penalties. Slater's stance: "The Broncos have totally gotten away from their stretch-run scheme. That leads to undersized linemen getting exposed."
5. Seattle — After losing their left tackle in training camp, the Seahawks limped through the first half of the season with an anemic running game. They traded for Pro Bowl tackle Duane Brown, but now he's hurt. What's more, Seattle's line is constantly penalized, and it doesn't help that Russell Wilson holds onto the ball so long. Slater's stance: "This group relies on the dynamic play of its quarterback. It's a line that's high on athleticism but low on skill."
Also struggling — Other than the Rams, it has not been a good year for offensive lines in the NFC West. A case can be made that both San Francisco and Arizona could be in the bottom five. … The lines in Buffalo and Houston also have fallen short of expectations.