49ers-Seahawks preview and prediction: Can Brock Purdy and Kyle Shanahan finish off an improbable regular season with a win?

49ers-Seahawks preview and prediction: Can Brock Purdy and Kyle Shanahan finish off an improbable regular season with a win?
Niners Nation Niners Nation

We’re nearly two months removed from the San Francisco 49ers allowing 42 points at home to the then Super Bowl favorite Los Angeles Rams. The result dropped the Niners to just one game over .500, leaving many fans skeptical about a playoff berth.

That was Week 10. We’re heading into the final week of the season, and not only do the 49ers have one more win than the Rams, but Kyle Shanahan, not Sean McVay, is the coach playing for the one season to close out the regular season. The Niners have gone from under a three percent chance to earn a bye to a coin flip.

Shanahan will have to do it against one of the best defensive minds and defensive lines in the NFL. The Seattle Seahawks have also won six consecutive games. Mike Macdonald is tied for the most wins in the NFL in just his second season as a head coach. He’s quickly ascended into one of the more impressive coaches there are in this league, presenting a unique challenge for the 49ers in Week 18.

For much of the season, the 49ers have been involved in higher-scoring games. The Niners’ offense has been able to dictate the pace, get out ahead of their opponent, and cruise to a victory.

Stringing together multiple first downs against this Seahawks defense has been a struggle for most teams they’ve faced, let alone touchdown drives. The Rams were the only team to make Seattle look league average, but they score against everybody. Then again, so do the 49ers.

Saturday night, for the No. 1 seed, it’ll be best on best on one side of the ball, and a pair of units limping to the finish line on the other. Let’s start with the side of the ball that’ll determine the matchup.

49ers passing attack versus the Seahawks’ passing defense

A battle of the bigs

We didn’t think there was a reason to mention the 49ers’ offensive line against Chicago’s defensive line last week, as they hadn’t shown the ability to get after the quarterback. Sure enough, Brock Purdy was pressured on only 23.7 percent of plays, the offensive line allowed more than a yard before contact, and the unit continued to roll despite not having Trent Williams.

The 49ers’ offensive line has been gelling for a month now. For the first few games of the season, they didn’t know who to block in the running game. Now, they are as synchronized as they’ve been all year. The play below is a prime example:

We’d be doing you a disservice to ignore the trenches this week, so let’s start there.

Interior pressure is king in the NFL. The Bears’ top defensive tackles have combined for 53 pressures this year. Byron Murphy and Lenoard Williams have 44 pressures each. They have combined for the most of any defensive tackle duo, and are the only interior combo to rank in the top 10 in pressures at their position in two...