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Detroit Lions vs. San Francisco 49ers preview, prediction: On Paper

Our statistical preview series kicks off with a Week 1 NFC bout.

NFL: Detroit Lions at San Francisco 49ers Kyle Terada-USA TODAY Sports

Yes, On Paper is back, which officially signifies the return of Detroit Lions football (to me). If you’re new here, let me run through a quick tutorial for my On Paper preview.

At the core of On Paper is the desire to compare units that will actually face each other. I’ve never understood the NFL previews that compare “Lions offense to 49ers offense: Advantage Lions.” Those guys don’t even play each other.

So On Paper is split up into four sections: one team’s passing offense vs. the other team’s pass defense, and the same with the run game. Then flip offense and defense for both teams.

For each team’s unit, I use a chart to compare their weekly performance to season averages. For example, if Jared Goff throws for 310 yards and a 98.0 passer rating, that seems like a pretty good day. But in On Paper, we put it in its proper context. So if that performance comes against the best defense in the league that is allowing just 220 yards and an 85.0 passer rating on the season, it’s a fantastic performance. Each weekly performance is charted, compared to season averages, and color coded. Beating weekly averages earn a green cell. Performing below averages earns a red cell. And if the performance is within 5 percent of averages the cell is yellow.

Admittedly, I’m not entirely happy with the statistics used in each chart—yards, yards per carry, and passer rating—but those are the best available stats that are available both on a weekly and season-long basis. To make up for the limitations of those stats, I offer more meaningful stats in the text below each section.

At the end of each matchup, I offer an advantage on a scale of 0-5 based on both how lopsided the matchup is and how integral I believe it will be to the overall game outcome. There is no magical formula for this advantage. It’s a mix of data and feel.

Lastly, because we’re at the beginning of the season, we’ve only got 2020 data to work with. I’ll try to acknowledge the limitations based on changes in personnel and coaching, when applicable. By Week 4, we’ll only be using 2021 data.

Alright, let’s get to it.

Lions pass offense (15th in DVOA for 2020) vs. 49ers pass defense (7th)

I’m not even going to bother discussing the data above. Matthew Stafford is gone. Almost every receiver from 2020 is gone. There’s a new head coach, offensive coordinator, quarterbacks coach, etc. The Lions' passing offense in 2021 will not resemble that of 2020 in any way.

So what do we know? We know the wide receivers probably aren’t that good, as evidenced by the fact that Trinity Benson—a player who has never been on a 53-man roster and was traded for a week ago—will likely have a role on Sunday. We know that Jared Goff has been good in the past—really good—but he’s coming off two below-average seasons, and he looked timid in training camp. We also know that starting left tackle has an injured finger and the outlook may not be great for his availability.

But Detroit does have some good things going for them. T.J. Hockenson is coming off a Pro Bowl season and appears to have developed chemistry with Goff. The Lions also have some receiving threats in their backfield that will likely make some noise.

So... we’ll see. I don’t have any fancy stats to throw at you in this section, but if I had to guess, this offense is going to have a slow start to the season.

Despite dealing with all the injuries they did, the 49ers' pass defense remained fairly solid last year. Just four teams managed to surpass a 100 passer rating against the defense and just two crossed over the 300 net passing yard threshold.

In total, they allowed just 6.6 yards per attempt (fourth), a completion percentage of 63.5 (10th), and a passer rating of 88.6 (eighth). Those are even more impressive numbers when you consider the 49ers ranked in the bottom half of the league in interceptions (12) and sacks (30).

This offseason, the biggest changes to the defense were schematic. With defensive coordinator Robert Saleh now head coaching the Jets, up-and-comer DeMeco Ryans has taken over and appears to be a little more fluid with what he does with the defense.

Of course, getting Nick Bosa back and Dee Ford back from injury is going to be a big deal, too.

Player to watch: Whoever is playing left tackle. With Decker’s availability very much in question, the Lions are faced with three very unappealing options to counter Bosa.

  1. Move rookie Penei Sewell—who has been transitioning to the right side all offseason—to left tackle this week
  2. Start Matt Nelson, who has one career NFL start, at right tackle
  3. Promote Will Holden—signed to the practice squad on Thursday—to the active roster and have him start at left tackle

Whichever option the Lions choose, they better bring some help. Or Taylor Decker plays and the Lions stand a chance.

Advantage: 49ers +3. To avoid the 49ers’ dangerous pass rush, the Lions are likely to get the ball out quick. They’ll need plenty of YAC from their receivers, and expect guys like Hockenson and D’Andre Swift to be targeted early and often. However, with a weapon like linebacker Fred Warner in coverage, don’t expect that strategy to work for long. Eventually, the 49ers will challenge the Lions to beat them over the top, and I don’t know if Goff will have the time—or the open receivers—to do that.

Lions run offense (21st) vs. 49ers run defense (10th)

For the 100th season in a row, the Lions failed to establish a running game. There were flashes, but it just wasn’t consistent enough to put any fear into opposing defenses.

This data is still somewhat relevant to the Lions, seeing as they have the same starting running back, most of the same offensive line, and the same offensive line coach. Differences include more depth behind Swift (Jamaal Williams), a run-mauling first-round pick in Penei Sewell, and a brand-new offensive scheme.

The Lions want to develop a physical mentality, and there’s little doubt building a running game is part of that goal. They’ve got all the components of a successful running game, but none of the proof that it’s actually there.

Again, the conclusion here seems to be the defense was not nearly as bad as many made it out to be, and they could be even more dangerous with a fully healthy roster. Just two teams were able to significantly outperform their season-long YPC average against SF, and they faced a lot of pretty darn good rushing attacks. In total, they allowed just 4.0 yards per carry (sixth and just 23.7 percent of rushes against the 49ers ended up earning first downs (ninth).

This year, it’s just more of the same. There’s no real reason to expect any regression from this unit, and it’s perfectly reasonable to expect an even better performance this year.

Player to watch: Darren Fells. One reason the Lions’ run game struggled at times during the preseason was the lack of good run blocking on the edges from Detroit’s poor tight end depth. While Fells is a better pass blocker, he’s also a much better run blocker than anyone else we saw in the preseason. He’ll need to help Detroit’s tackles against the 49ers' impressive edge defenders.

Advantage: 49ers +1. I want to believe in the Lions' rushing attack. I really do. But I’ve been burned so many times that I just can’t give them the benefit of the doubt. Unfortunately, Week 1 presents a really tough challenge. But if they can show some success on Sunday, it’ll go a long way to building my confidence in the unit.

49ers pass offense (22nd) vs. Lions pass defense (32nd)

*Games started by someone other than Jimmy Garoppolo

It’s hard to see any noticeable difference in the passing game efficiency with and without Garoppolo. Statistically, there was a difference, but it wasn’t as much as you’d see with most starters vs. their backups.

Garoppolo: 67.1 completion percentage, 7.8 Y/A, 7 TDs, 5 INTs, 92.4 passer rating
Backups (Nick Mullens, C.J. Beathard): 64.4 completion percentage, 7.5 Y/A, 18 TDs, 12 INTs, 89.3 passer rating

We see a similar impact when we simply look at the 49ers pass offense with and without George Kittle:

With Kittle (8 games): 65.3 comp. %, 7.7 Y/A, 13 TDs, 7 INTs, 93.8 passer rating
Without Kittle (8 games): 64.9 comp. %, 7.5 Y/A, 12 TDs, 10 INTs, 86.8 passer rating

With both Garoppolo and Kittle back, the 49ers' passing offense should be at its best... which is to say pretty average. I love the offensive mind of Kyle Shanahan, but he makes his money in the run game. Still, with weapons like Kittle and Deebo Samuel, they will keep you honest.

This is another set of data I’m willing to completely throw out. Detroit’s defensive scheme has been overturned, their front seven is unrecognizable from what it was last year, and Detroit’s young and moldable secondary seems to be playing at a different level from 2020—though, granted, that’s from practice and preseason observations.

It’s really an impossible unit to predict. Detroit added a bunch of pass rushing threats on the interior in rookies Alim McNeill, Levi Onwuzurike, and veteran Michael Brockers. They bring back a healthy Trey Flowers (missed nine games in 2020), and Romeo Okwara (10 sacks last year) looks better than ever.

But Detroit’s young secondary is a major unknown. From a statistical standpoint, they were awful last year, but, again, this defense is unrecognizable from last year. As much as I love Detroit’s defensive coaching staff—especially with its focus on the defensive backs—it’s hard to predict a complete turnaround in one season. I think it’s more likely this is an average-to-below-average unit in 2021.

Player to watch: Whoever the Lions put on Kittle. The Lions have notoriously struggled to cover tight ends over the past few years, but the linebacker room has gone through significant changes this year. Jarrad Davis and Jahlani Tavai are gone after failing to reach their potential, and they’re replaced by veteran Alex Anzalone, and rookie Derrick Barnes coming off the bench. Will either of them get Kittle? Will Jamie Collins draw coverage duties? Do the Lions drop down a safety? Hard to know.

Advantage: Even. There’s nothing outside of Kittle that is truly that scary about the 49ers’ passing attack. I expect the Lions' defense to be better this year, but it remains to be seen how much better. With that low of confidence in any sort of conclusions, I have to call this one a draw.

49ers run offense (15th) vs. Lions run defense (27th)

While it’s a bit surprising to see the 49ers running offense chart this bad, a deeper dive into the stats show it is kind of misleading. Let’s look at the 49ers’ top backs from last season:

Jeff Wilson Jr: 126 rushes, 600 yards, (4.8 YPC), 7 TDs
Raheem Mostert: 104 rushes, 521 yards (5.0 YPC), 2 TDs

Mostert missed eight games last season, and it showed. Again, here at the 49ers running game statistics with and without him:

Games with Mostert: 227 rushes, 1,014 yards, 4.5 YPC
Games without Mostert: 210 rushes, 875 yards, 4.2 YPC

The 49ers return most of the members from last year’s team, plus veteran center Alex Mack, who has quietly been one of the best run blocking centers for his illustrious 12-year career.

Yes, this chart surprises me just as much as it probably surprises you. Unfortunately, it’s fool’s gold, as evidenced by the DVOA ranking. Detroit stuffed runs (stopped at or before the line of scrimmage) just 12 percent of the time (29th) per Football Outsiders, and they weren’t much better in short-yardage situations, earning stop 67 percent of the time (17th).

However, this defensive philosophy has changed. They won’t be asked to hold their gaps and wait for the play to come to them. Instead, they’ll be encouraged to attack and penetrate. That philosophy should get them more negative plays in the run game than last year, especially considering they have the personnel to accomplish it.

Player to watch: McNeil vs. Mack. A 35-year-old, six-time Pro Bowl center vs. a rookie, 21-year-old nose tackle. For those of you that love gritty football (Hi, Dan Campbell, thanks for reading), this will be a fascinating matchup to watch.

Advantage: 49ers +1. The one thing I didn’t talk much about in this matchup is misdirection. The 49ers thrive on it, and it was the conversation all week in Allen Park. Just about every defensive player and coach we talked to spoke of their need to stay disciplined. That’s much easier said than done, and with an extremely young roster, I expect the 49ers to fool the Lions' defense on more than one occasion here. That being said, I could see the Lions' defense hang with the 49ers' offense for most of the day.


Unsurprisingly, the 49ers come out looking like the much better team. They hold a commanding +5 advantage and by On Paper standards, that’s a pretty significant lead. But while they hold an advantage in three of the four matchups, two of those are just by +1. If the Lions can finally establish a running game against the 49ers, I do think they have a chance to keep it close or even pull off an upset.

Unfortunately, that relies simply on faith, and faith doesn’t tip the scales here at On Paper. Based on everything we know and have seen, this 49ers team is just better. 49ers 23, Lions 13.

Remember to submit your scores in the comment section below. Closest to the actual score will get a shoutout in next week’s On Paper.

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