The 49ers “NC-17” defense suffocates the Seahawks en route to NFC West Title

I’ve been thinking long and hard about a nickname for the 49ers’ defense, scouring all facets of the internet trying to come up with a San Francisco-themed moniker for this outstanding unit.

Then, after the 49ers dominated the Seahawks en route to their second NFC West title in four seasons, the communications department sent out their weekly Game Notes email, and it instantly hit me.

One of the first notes they mentioned was that the 49ers’ defense had held opponents to 17 points fewer in seven straight regular season games. This is the first time that has happened since 1984. It’s taken 38 years for a defense to have a streak like this.

Which got me thinking — how about we call this defense the “NC-17” defense because they hold teams to less than 17 points consistently? They’ve held opponents to less than 17 points in 11 of their 14 games this season and have done it seven consecutive times (all wins, by the way).

DeMeco Ryans and this 49ers’ defense has become so good that it seems unusual when they give up touchdowns in the second half. When the Seahawks scored their late fourth-quarter touchdown tonight, it was only the third touchdown the 49ers have given up in the second halves of the last seven games.

In the last seven games, the 49ers’ defense has given up a total of 24 points in the second half — which sounds insane but is true.

Ultimately, San Francisco’s Super Bowl ceiling rests on the shoulders of Brock Purdy and the 49ers’ offense, but their floor is extremely high because of what the defense has been able to do this season.

On Thursday night, the 49ers’ defense forced seven punts and a fumble on eight of the Seahawks’ 11 offensive drives. They stifled Seattle’s offense, only allowing 4.5 yards per play and only allowing them to convert on 31 percent of third downs.

They forced a turnover, sacked Geno Smith three times, and clobbered him all night long in the pocket.

Their defensive playmakers showed up at all three levels. Starting with Arik Armstead and Nick Bosa, who pushed the pocket and made Smith’s life difficult. Fred Warner and Dre Greenlaw seemed to be in on every play, including a forced fumble on Travis Homer.

Charvarius Ward was in D.K. Metcalf’s hip pocket all night long, only allowing him to get 55 yards. Deommodore Lenoir led the 49ers’ defense in tackles, and Talanoa Hufanga also forced a fumble that Seattle recovered.

DeMeco Ryans’ unit is fundamentally sound at all three levels. They are well-coached and play with their hair on fire for the 60-70 snaps when they’re on the field.

But at the end of the day, the key number that continues to pop up is 17, and that’s why I think this defense will be called “NC-17.”