Detroit Lions @ San Francisco 49ers

Three games. That’s all that remains of the 2023 NFL season, starting with this weekend's NFC Championship showdown between the Lions and 49ers. The 49ers will have home field advantage in this game as the No. 1 seed and are currently seven-point home favorites.

It hasn’t exactly been smooth sailing for either San Francisco or Detroit thus far in the playoffs. The 49ers were lucky to survive last week in a rainy game against the Packers, and the Lions have squeaked past the Rams and Buccaneers with a couple of close, one-score wins in back-to-back weeks.

San Francisco’s biggest problem last week was their offense, which stands out as an outlier. The 49ers were the best offensive team in football during the regular season, having led the league with their average +0.179 EPA per play. They weren’t too far off that mark against the Packers last week at +0.169 EPA per play, but that ranked just fourth among the eight teams that played in the Divisional Round.

The issues stemmed from Brock Purdy. The 49ers’ QB was the most efficient passer in football during the regular season, having led all QBs in EPA + CPOE composite, QBR, and adjusted yards per attempt (AY/A). However, Purdy's AY/A plummeted from 9.92 during the regular season to just 6.97 against the Packers last week. Green Bay doesn’t have a particularly imposing defense, so it was a concerning performance.

San Francisco 49ers quarterback Brock Purdy (13) throws a pass during the third quarter of their NFC divisional playoff game Saturday, January 20, 2024 at Levi Stadium in Santa Clara, California. The San Francisco 49ers beat the Green Bay Packers 24-21. Photo Credit: Mark Hoffman / Milwaukee Journal Sentinel / USA TODAY NETWORK

Purdy will always have his doubters. He was the last pick of the 2022 NFL Draft, and despite his massive passing numbers, there will always be some who don’t believe in his talent. And while Purdy has certainly benefited from Kyle Shanahan's scheme and the playmaking talent of his surrounding cast, that shouldn't detract from the fact that Purdy has executed Shanahan’s system to perfection this year. None of Shanahan’s previous QBs have come close to producing the efficiency metrics that Purdy has in 2023.

There are reasons to believe in a bounce-back game for Purdy this week against the Lions. He clearly struggled with the elements last week, which were outlier conditions for San Francisco. The rain was torrential at times during the game, and Purdy never seemed comfortable gripping or throwing the football in those conditions. It was also his first game in three weeks coming out of their first-round bye, so there was perhaps some rust for Purdy to shake off.

On top of those mitigating factors, San Francisco also lost Deebo Samuel to a shoulder injury early in the game against Green Bay. As Ian Hartitz pointed out in his recent article, Purdy hasn’t been nearly the same player without Deebo in the lineup:

• With Deebo (19 games)
  • +0.362 EPA per dropback
  • 87.2 Pro Football Focus (PFF) pass grade
  • 119.5 passer rating
  • 38-7 TD to INT rate
  • 9.4 YPA
  • 70.4% completion rate
• Without Deebo (7 games)
  • +0.124 EPA per dropback
  • 65.4 PFF pass grade
  • 80.6 passer rate
  • 10-7 TD to INT ratio
  • 8.3 YPA
  • 62.9% completion rate

As it stands, Deebo's status for the NFC Championship game against the Lions is still in doubt. ESPN’s Adam Schefter has reported that he’s 50/50 to suit up for Sunday's matchup.

January 20, 2024; Santa Clara, CA, USA; Green Bay Packers linebacker De'Vondre Campbell (59) and linebacker Quay Walker (7) and cornerback Jaire Alexander (23) tackle San Francisco 49ers wide receiver Deebo Samuel (19) in the during the second quarter in a 2024 NFC divisional round game at Levi's Stadium. Mandatory Credit: Kyle Terada-USA TODAY Sports

Losing Deebo would obviously hurt, but it may not slow down the 49ers' offense that much. The Lions have had one of the worst pass defenses in football all year long, and they’ve likewise struggled in the postseason. Matthew Stafford threw for 367 yards and two TDs against Detroit two weeks ago, and Baker Mayfield just shredded them for 349 yards and three TDs.

Even if Deebo were to miss this game, Purdy would still have Brandon Aiyuk and George Kittle at his disposal, not to mention a dynamic dual-threat RB, perhaps the best in the NFL, in Christian McCaffrey. Plus, the current weather forecast looks immaculate for Sunday afternoon, so San Francisco's offense should return to running as a well-oiled machine against Detroit.

On the other side, the Lions have a potent offense of their own. They ranked eighth in EPA per play during the regular season, and they rank fourth through the first two rounds of the playoffs. Detroit's offense is also versatile, ranking top-seven in EPA both on the ground and through the air, so they’re capable of beating defenses in multiple ways.

However, it's worth noting that the Lion's first two playoff victories have come at Ford Field in Detroit, which has been Jared Goff's comfort zone. He’s historically been at his best when playing in a dome, having gone 36-17 ATS when playing indoors. When playing outdoors, Goff has gone just 34-35-2 ATS, and he's been 9-14-1 ATS outdoors in December and January.

Detroit Lions quarterback Jared Goff (16) talks to teammates before a snap against Tampa Bay Buccaneers during the second half of the NFC divisional round at Ford Field in Detroit on Sunday, Jan. 21, 2024. Photo Credit: Junfu Han / USA TODAY NETWORK

Of course, there's a vast difference between San Francisco and a city like Buffalo in January, so it's not a worst-case scenario for Goff.

Still, he'll need to dissect an extremely tough 49ers defense. Their defense ranked sixth in dropback EPA allowed during the regular season, which makes them the best pass defense that Goff has faced yet in the playoffs. The Rams (18th) and Buccaneers (22nd) were both subpar against the pass, so this matchup will be a big step up in competition.

The 49ers are likely to put up points, so the Lions' offense will need to play at peak efficiency if they want to have a chance in this game. That said, is it possible that Detroit can at least score enough points to cover the spread?

The public seems to believe in Detroit, as they have received 52% of the early spread bets per the Action Network. Dan Campbell has an elite track record as an underdog, and with the 49ers having looked mortal against the Packers, many bettors are feeling comfortable with grabbing the seven points.

I disagree. I already bet the 49ers at -6.5 last Sunday, which you can find in our NFL Bet Tracker. Even if Deebo were to miss this matchup, I still think that seven points is about right. And if Deebo is active for this game, I think that this number deserves to be above seven. 

Now that the line is at 7.0 across the industry, I’m not nearly as bullish on San Francisco. However, if you can find -6.5 anywhere prior to kickoff, I wouldn’t hesitate to grab it. The Massey-Peabody Power Ratings had the 49ers as more than eight points better than the Lions on a neutral field heading into last week, and one down game shouldn’t change that too much.