49ers Defensive Line Will Determine San Francisco’s Fate in 2016


The San Francisco 49ers started the rebuild of this franchise from the trenches, and the team’s defensive line will be one of the main factors in determining how successful the Niners are against the rest of the NFL in 2016.

The San Francisco 49ers may not be a team boasting a ton of strength across the board. But, if there’s one area in which the team can feel pretty good about entering the 2016 season, its along the defensive line.

2016 marks the second consecutive season in which general manager spent the team’s first-overall pick in the NFL Draft on a defensive lineman.

Last year, it was former Oregon defensive end Arik Armstead. This year, former Duck teammate DeForest Buckner was tabbed by San Francisco.

Not long ago, Niner Noise described why running back Carlos Hyde needed to be the linchpin of the offense to ensure success in 2016. On the flip side, it’s not just one player who needs to make a difference. It’s the entire D-line unit.

It makes sense.

Defensive lines are part of the foundation upon which the rest of an NFL team is built. Along with the offensive line counterpart, football games are won or lost in the trenches.

So, judging by San Francisco’s 2015 D-line rankings — 24th against the run and 29th against the pass, according to Football Outsiders — it’s easy to understand a big reason behind the Niners finishing with a 5-11 record last year.

Both Buckner and Armstead figure to be major players in this unit’s success this season. Armstead came on strong towards the end of last year and finished with a plus-15.1 overall grade, according to Pro Football Focus (subscription required), which was second among all 49ers defenders.

And he certainly has to be thrilled about reuniting with Buckner and both players’ former UofO head coach Chip Kelly, as seen in the video below:

So far, Armstead has been one of the more impressive players to watch in training camp.

This bodes well for San Francisco’s O-line, but the unit isn’t without it’s own set of major questions.

Sep 7, 2014; Arlington, TX, USA; San Francisco 49ers nose tackle Ian Williams (93) on the field during the game against the Dallas Cowboys at AT&T Stadium. San Francisco beat Dallas 28-17. Mandatory Credit: Tim Heitman-USA TODAY Sports
Sep 7, 2014; Arlington, TX, USA; San Francisco 49ers nose tackle Ian Williams (93) on the field during the game against the Dallas Cowboys at AT&T Stadium. San Francisco beat Dallas 28-17. Mandatory Credit: Tim Heitman-USA TODAY Sports /

Chief among these is how the defense will make up for the season-ending loss of nose tackle Ian Williams. Williams, who was the 49ers’ top-ranked defender last season (plus-24.4), according to PFF, was one of the premier run-stoppers in the league.

According to Matt Barrows of the Sacramento Bee, nose tackle Mike Purcell has emerged as the favorite to take over Williams’ spot along the line, and especially in run-defense formations. Over 294 snaps last year, Purcell posted a plus-1.1 against the run but a minus-4.4 against the pass, per PFF.

With veteran defensive tackle Glenn Dorsey still rehabbing from a torn ACL, fellow DT Quinton Dial may wind up being the primary backup and first-tier rotational player for the line.

It’s not a bad move either. Regardless who Kelly — or defensive coordinator Jim O’Neil, for that matter — tabs as the starters in San Francisco’s 3-4 base defense, Dial will get his fair share of snaps.

Not forgotten in the mix is rookie Ronald Blair, whom the Niners tabbed in Round 5 of the NFL Draft.

And yet everything seems to come back to Buckner and how his impact will be felt, which looks to be right off the bat.

Buckner is even more promising a prospect than Armstead was when he went pro. And Buckner’s collegiate sack totals (18 to four in favor of Buckner) make this year’s first-round draftee appear to be even more of an imposing figure.

But it doesn’t hurt Armstead registered 30 quarterback pressures, per PFF, which was second only to linebacker Aaron Lynch last year.

This all sounds fine and dandy, and it would be great to tout how wonderful San Francisco’s offensive line will be this season. Yes, this unit is promising. But there are some very real weaknesses on the table.

With Williams gone, the Niners’ efforts at stopping the run are going to be that much more difficult — an aspect pointed out, especially in sub packages, by Chris Biderman of USA Today’s Niners Wire:

"The 49ers were cognizant of their struggles defending the run in sub packages and tried to make up for it by keeping Williams, a nose tackle, on the field as a defense end. And while that was done to stop the run, it hurt the pass rush. Williams has two sacks in his five seasons. If nose tackles were good pass rushers, they wouldn’t be nose tackles.Clearly having Williams play in sub wasn’t enough. It’s going to be up to the younger defensive linemen, Armstead and Buckner, to stop the run if the 49ers are going to compete in 2016. The Eagles finished last in time of possession in all three seasons under Chip Kelly while he ran his no-huddle, up-tempo offense."

Fortunately, PFF’s scouting report on Buckner highlighted his abilities against the run, so this issue may not be as pressing a concern. We’ll see.

More from Niner Noise

Regardless, the 49ers defensive line will be controlling the defensive pace of the game and doing its best to limit what offenses will try to do in order to keep this, and other defensive units, on the field.

Stopping the run will be the best way to ensure this doesn’t happen, but so will opening up lanes to other teams’ quarterbacks.

And, as with Hyde on the opposite side of the ball, San Francisco’s 2016 season will hinge on what the D-line will be able to do.

Next: Fans Should Watch 49ers DE DeForest Buckner in Camp

All statistics, records and accolades courtesy of Pro-Football-Reference.com and Sports-Reference.com unless otherwise indicated.