Elevated Stats: Broncos offensive line not pulling its weight

When looking at Elevated Stats around the web, most units on the Denver Broncos grade out positively. Of course, the defense is stellar - it's the top-rated defense in the league across the board. Peyton Manning has been underwhelming, but the Broncos' pass offense still has a +1.0 grade on the year. But the offensive line is atrocious - it is negative in both run blocking and pass blocking no matter where you look. According to PFF, the only other areas the Broncos grade negatively are at quarterback, running back and with penalties overall, and each of those grades could turn positive with one strong game. Denver's offensive line is its only "very-negative," a -18.1 PFF grade.

PFF isn't alone here - Football Outsiders' pass-blocking and run-blocking metrics have the Broncos ranked low as well, 30th in run-blocking and 17th in pass protection.  A week ago, Ben Muth of Football Outsiders outlined the issues the Broncos are facing brilliantly, highlighting misses at the tackle position in particular. This week, a Broncos fan on this site going by "thetapedoesntlie" posted a handful of film reviews that showed both mental errors and physical defeat on the part of the Broncos' blockers. It isn't a pretty sight.

In short, Denver's offensive line continues to be its Achilles Heel.

Still, football is a total team game, and there are a handful of teams that are doing alright this year with shoddy offensive line. The Denver Broncos are one of them (they are 5-0, after all). The Green Bay Packers' O-line grades out even worse thanks to a putrid -22.8 grade in run blocking. And the Jets are chugging along at 3-1, despite poor O-line pay, thanks to a resurgent defense. But the other 11 teams with a lower PFF O-line grade than the Broncos each have a losing record, including the NFC Champion Seattle Seahawks, who post double-digit negative grades in both run blocking and pass blocking.

Unless you're stellar at another area, you can't afford to have a weakness at O-line in the NFL.

It isn't clear what the Broncos can do to improve this unit. They're naturally getting better in some areas as the season progresses - Evan Mathis and Louis Vasquez each had their best games a week ago. But the injury of Ty Sambrailo has doomed any chances of continuity leading to improvement for the offensive line. He may be back in the lineup this Sunday, but missing those two weeks could prove detrimental to his progress through the early part of the season and to the chemistry of this offensive line.

While Peyton Manning's play has gotten the most attention this week, it's the offensive line that really needs course-correction if this offense is going to improve by the postseason.

Elevated Stats, Week 6

While stats don't tell the whole story, our Elevated Stats from 5,280 feet aim to give you a Mile-High perspective on the Denver Broncos and the NFL by covering all the bases. As always, here are your explanations for the analytics used in Elevated Stats. In the future, we may refer to this post instead of posting this glossary each time.

Record. Wins and losses. There isn't a more important "statistic" in football.

SOS: Strength of Schedule. The collective winning percentage of a team's opponents so far. Gathered from ESPN.

DVOA: Defense-Adjusted Value Over Average. Football Outsiders' prized statistic, DVOA, measures a team's efficiency by comparing success on every single play to a league average based on situation and opponent. It's a beast.

PFF Grade. After PFF grades disappeared from Elevated Stats two weeks ago, a Good Samaritan was kind enough to donate the necessary numbers for us to continue incorporating PFF grades for now. That may not be sustainable long-term, so we're exploring options for the weeks ahead. The Elevated Stat here simply represents a sum of each team's cumulative grades: offense + defense + special teams. PFF grades each player on each play, then sums them up. The higher the number, the better.

PRD: Passer Rating Differential. This is simply the difference between a team's Offensive Passer Rating and its Defensive Passer Rating (the collective passer rating of QBs in games played against the team). While it seems overly simple, in this quarterback-driven league, Passer Rating Differential actually has an incredibly high Correlation to Victory and is considered the "Mother of all Stats" at Cold Hard Football Facts.

SRS: Simple Rating System. Pro-Football-Reference.com's go-to statistic takes a team's points and compares them to their opponents' points. It takes no other metrics into account. An average SRS is zero. There are strengths and weaknesses to this approach (such as a 44-20 win being considered "better" than a 20-0 win, which it isn't), which are covered nicely in PFR's guide on SRS here. SRS derived from this table each week.

TO: Turnover Ratio. Finally, another common, simple, but all-important measurement: turnover ratio. Gathered from NFL.com.

AFC observations

• The New England Patriots are beginning to separate themselves from the rest of the AFC. They're either a leader or in the Top 4 in every category in our Elevated Stats.
• The Broncos are middling in a few areas largely due to the (lack of) strength in their schedule - they're the lowest in SOS so far, and that impacts other areas that take strength of opponent into account, including DVOA and SRS.
• If we were to create some sort of Cumulative Elevated Stat Ranking based on the curvature of these grades compared to historic averages - something we've been keen to do but haven't had time to - our eyeballs tell us the Bengals would top the Broncos, as they outrank them in a number of areas.
• Bill Barnwell notes that the Broncos have the NFL's best first-down defense and its best third-down defense. He doesn't break down second-down defenses, but let's just wager that the Broncos aren't bad there, either.
• On the offense, though, Barnewll notes Denver is worst on third downs and second-worst in the red zone. Ugh.

Head-to-head observations

• Strength vs. Strength: The Browns boast the top-graded pass-blocking offensive line in the NFL, but they've faced some meager competition. Their Adjusted Sack Rate according to FO, which does incorporate strength of opponent, ranks them 26th.
• That unit will face a Denver Broncos pass defense that is ranked 1st by PFF and 2nd by FO.
• The Browns have had a tougher schedule than the Broncos so far as far as wins and losses go. Like the Broncos, they've had three away games so far.
• Josh McCown broke two Browns franchise records a week ago at quarterback -  yards thrown (457) and consecutive 300-yard games (three). He has six touchdowns and one interception on the year for a 102.8 passer rating and an ESPN QBR of 73.9.
• However, McCown has faced nothing like the Broncos defense to date.
• Peyton Manning has six touchdowns, seven interceptions, a 77.3 passer rating, and a 51.7 QBR.
• Despite 25 points in passer rating difference, the Browns still only beat the Broncos in PRD by roughly five points, telling you how different these two defenses are.

Got something to add to our Elevated Stats? Hit us up in the comments!

Update: We misread one of our Elevated Stats and incorrectly said Peyton Manning has a +1.0 PFF Grade for the year. That's incorrect; it's -3.7. The Broncos' cumulative Pass grade is +1.0. We regret the error.