49ers must improve versus the run for defense to be elite

Malcolm Brown #34 of the Los Angeles Rams tries to outrun Fred Warner #54 of the San Francisco 49ers (Photo by Joe Scarnici/Getty Images)
Malcolm Brown #34 of the Los Angeles Rams tries to outrun Fred Warner #54 of the San Francisco 49ers (Photo by Joe Scarnici/Getty Images) /

The 49ers defense was ranked one of the league’s best in 2019, but the run defense was sub par. Improving it will make the Niners an elite unit.

Few would argue against the San Francisco 49ers defense in 2019. After all, when a team finishes No. 8 in the league in points allowed and No. 2 in points against, it’s pretty safe to say whatever formula was being employed worked.

But to be picky, which is never a bad thing for a Super Bowl-caliber team, one needs to look at the few weaknesses that exist. Those, after all, are going to be what opponents target when trying to beat the Niners this upcoming season. And with no fans at Levi’s Stadium, there won’t be the benefit of crowd noise working to San Francisco’s defensive benefit.

One of those key weaknesses was against the run. Overall in 2019, the 49ers gave up 1,802 yards on the year, which ranked 17th. And the average of 4.5 rush yards allowed per attempt was 23rd. True, most teams have switched the nearly league-wide M.O. of using a pass-first offense. But when considering other top-contending teams like the Baltimore Ravens and Tennessee Titans, who have gone against the grain by featuring a dominant run game, just like the Niners, it’s pretty easy to see why this is important.

In some ways, this was predictable. In 2019, defensive line coach Kris Kocurek implemented a wide-9 alignment for the D-line, essentially spreading out the front four. While this served to open up more outside-rush lanes for the 49ers’ pass-rushers, it also made the defense more susceptible against interior runs.

In 2018, when the Niners were using more Cover 3 looks with a 4-3 Under format, pressing the strong-side (SAM) linebacker and strong safety up towards the line of scrimmage, coordinator Robert Saleh’s defense allowed just 4.1 yards per carry — seventh best in the league.

That came at the expense of the pass rush, though. So, without giving up the 49ers’ lethal pass-rushing prowess, there is a way Saleh and Co. can engineer a change.

It’s something also pointed out by Sports Illustrated’s Jose Sanchez, who argued San Francisco would be better served by implementing more base defense in 2020 instead of predominantly featuring nickel packages.

Let’s dive into this a bit further.

Key 49ers players in a would-be shift to more base defense

Sanchez rightfully argued in favor of the Niners linebackers, namely Fred Warner, who is on the cusp of being a perennial Pro Bowler.

Warner, who’ll still occupy the middle (MIKE) role in 2020, demonstrated some key pass-defense abilities in 2019, although there was some weakness against the run. Per Pro Football Focus, Warner’s run-defense grade came in at a lowly 46.8, marked down by his team-high 20 missed tackles.

Regardless whether or not San Francisco puts out more base defense, subbing in a nickel defensive back for an extra linebacker (likely Dre Greenlaw), Warner needs to improve in this category to cut down on those extra yards after contact.

The 49ers have a luxury in linebackers with Warner, Greenlaw and Kwon Alexander. All three are more than effective covering passes, and teams would think twice about targeting any of those three in the intermediate areas of the field. Yet the Niners used their nickel packages 66 percent of the time last year. Putting in the extra linebacker, as Sanchez suggested, would help ensure teams aren’t as comfortable using the run without giving too much up against the pass.

Yet there are other players in the mix when it comes to providing a statistical uptick in run defense. San Francisco’s top pick in the 2020 NFL Draft, defensive tackle Javon Kinlaw, who is notably a better pass-rusher than run stopper. Kinlaw’s prowess can be improved with technique, though, and one might expect Kocurek to hone Kinlaw’s abilities towards eating up those inside rush attempts.

Kinlaw’s linemate, defensive tackle Arik Armstead, is another player to watch here.

“One thing we talked about: We were tops in a lot of categories except run defense — we were middle of the pack,” Armstead told reporters this week. “Definitely looking to get better in that aspect.”

Armstead, who led the Niners with 10 sacks last season, actually had a better run-stopping PFF grade (87.5) than pass-rush grade (75.6) in 2019. With San Francisco likely to move its defensive front around a lot in 2020, one might expect Armstead to be featured on the inside more during rushing downs, potentially spelling Kinlaw until his numbers in that category get better.

If all this comes into focus, and even if the Niners improve by cutting down an average of just half a yard per carry, those efforts will ultimately prompt Saleh’s defense into being one of the league’s elite.

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And that might just be enough of a difference between being a Super Bowl contender and champion.