Arik Armstead’s unselfish play a big reason for 49ers’ impressive run defense, says DeMeco Ryans

The San Francisco 49ers run defense has been as good as anybody's through the second half of the season. In fact, The Athletic's David Lombardi pointed out that the 49ers own the NFL's top run defense since their Week 6 bye. That's about when defensive lineman Arik Armstead moved to primarily play inside, filling in for an injured Javon Kinlaw.

The 49ers don't see that as a coincidence.

"I think our run defense improved drastically because of the unselfish play by Arik Armstead," defensive coordinator DeMeco Ryans said on Friday. "I think people kind of forget we lost our starter in Kinlaw early in the year, and we were trying to figure that out inside. When you want to play good run defense, you have to have two really good interior defensive linemen. And Arik unselfishly moving inside [helped], and D.J. Jones has been outstanding all year."

In his seventh NFL season, Armstead recorded a career-high 63 tackles, seven tackles for a loss, 11 quarterback hits, and six sacks through 17 games, per Pro Football Reference.

It's not just his support against the run that has helped the 49ers. Armstead's 52 total pressures rank eighth among interior defensive linemen, per Pro Football Focus, and his pass-rush grade of 78.0 is a carer-high.

"He has had a dominant year, a career year inside, and he's been consistent all year," Ryans continued. "That's why our run defense has been better because of Arik and his play. Arik continued to get better and better inside as the year went on. And D.J. has been as consistent as ever this year."

The 49ers enter Sunday's playoff game against the Dallas Cowboys with a defensive unit ranked third in total yards allowed (310.0 per game) and the seventh-ranked run defense (103.5 yards per game). Dallas is currently a three-point favorite.