The 49ers defense hasn’t been tested by any elite quarterbacks

When the Seattle Seahawks and San Francisco 49ers face off Monday night at Levi’s in a matchup with significant implications going forward for both the NFC West and NFC in general, the game will feature the number seven scoring offense against the number two scoring defense. The Niners defense, surrendering just 12.8 points per game through the first half of the season, has made a name as it has challenged numbers put up by historic defenses to this point in the season.

However, as fans have been quick to point out, Russell Wilson will be far and away the best quarterback the Niners defense will have faced, as the 49ers have not exactly faced a murderer’s row of quarterbacks. So far this season the quarterbacks San Francisco has faced include:

• Week 1: Jameis Winston
• Week 2: Andy Dalton
• Week 3: Mason Rudolph
• Week 5: Baker Mayfield (and Garrett Gilbert for a single snap)
• Week 6: Jared Goff
• Week 7: Case Keenum
• Week 8: Kyle Allen
• Week 9: Kyler Murray

So, that’s five quarterbacks on their rookie contracts, one quarterback who would be on his rookie contract if the Los Angeles Rams hadn’t given Goff a massive extension, Andy Dalton and Case Keenum. Not exactly a list that is going to instill fear in the hearts of fans.

However, thanks to the systematic scheduling system the NFL uses, the Seahawks have faced a slate of quarterbacks that is very similar. So far this year Seattle has seen

• Week 1: Andy Dalton
• Week 2: Ben Roethlisberger/Mason Rudolph
• Week 3: Teddy Bridgewater
• Week 4: Kyler Murray
• Week 5: Jared Goff
• Week 6: Baker Mayfield
• Week 7: Lamar Jackson
• Week 8: Matt Schaub
• Week 9: Jameis Winston

Remarkably, the two teams have faced a half dozen of the same quarterbacks through only the first nine weeks of the season, even given the fact that the 49ers have already had their bye week. Thus, the logical thing to do is to compare how the two teams have fared against common quarterbacks. So, here is a comparison of the games each quarterback both teams have faced had against the defense of each team.

First Andy Dalton of the Cincinnati Bengals:

Then Jared Goff of the Los Angeles Rams:

Moving on to Jameis Winston of the Tampa Bay Buccaneers:

Both teams have faced Kyler Murray of the Arizona Cardinals:

Baker Mayfield of the Cleveland Browns had his two worst games of the year against the Hawks and Niners:

And both teams faced Mason Rudolph of the Pittsburgh Steelers:

So, while the teams have faced several of the same quarterbacks, the majority of the time those quarterbacks have fared worse against the 49ers defense as compared to when they have faced the Seahawks defense. As for the cumulative numbers of the quarterbacks that have faced the two defenses, here are the numbers.

So, while the idea that the Niners defense has yet to face an elite quarterback is absolutely true, it’s also true that the San Francisco defense has outplayed the Seattle defense by most metrics when looking at the quarterbacks both teams have faced. This, obviously, does not prove that the 49ers defense is in any way elite, just that it has fared better in pass defense against the common quarterbacks the two teams have faced.

And these numbers don’t even start getting into the fact that the Seattle pass rush has registered just a 4.5% sack rate against these six quarterbacks, while the San Francisco defense clocks in at 10.3%.