One mismatch in the Rams’ favor: Cooper Kupp and Odell Beckham Jr. vs. 49ers secondary

Against man coverage, Kupp has generated a passer rating when targeted of 150.4 while racking up 715 receiving yards, both tops in the NFL, per Pro Football Focus. Of those 715 yards, 100 came against the Niners (on six targets), who allowed 15 TDs with zero picks in man coverage all season (though they did use man coverage at the fifth-lowest rate, 20.3 percent, in the NFL). But the mismatch does not end there. Per NGS, Kupp earned 1,470 receiving yards from the slot this season, a whopping 409 more than the next closest player in any season since NGS began tracking, in 2016. San Francisco, meanwhile, has allowed a 102.6 passer rating to slot receivers this season (including the playoffs), ranking 21st in the NFL. Kupp has thrived in the slot against the Niners specifically, averaging 94.5 yards per game from the slot in the Rams’ two games with San Francisco. (Kupp averaged 75.4 yards from the slot against all other opponents.) 

As for Beckham, who was signed prior to Week 10, he didn’t register much production against the Niners this season, logging just two catches for 18 yards in each game. He also hasn’t been a reliable deep option for QB Matthew Stafford (Beckham has generated a 10.0 completion percentage on deep attempts in Los Angeles, with one TD, three INTs and a 43.3 passer rating). But he has been incredibly valuable on short and intermediate passes, generating a 73.3 percent completion rate, five TDs, zero picks and a passer rating of 134.3, the highest of any WR on the team. And his production has ticked up significantly over the past two games, as has the subsequent attention paid by defenders, meaning he figures to stretch the Niners’ defensive backs (who are seen by my model as the worst group of DBs remaining) even thinner.

One mismatch in the 49ers’ favor: Generating effective pressure without blitzing (complemented by a knack for executing quick passes on offense)

Compare Stafford’s production this season when the Niners blitzed him to his production when they didn’t:

• FACING BLITZ: 158.1 passer rating, 2 TDs, 0 INTs, 88.9 completion percentage, 20 percent pressure rate.
• NOT FACING BLITZ: 61.3 passer rating, 2 TDs, 4 INTs, 60.9 completion percentage, 31.4 percent pressure rate.

The Niners lead the NFL in 2021 with a 30.5 percent pressure rate when rushing four or fewer (including playoffs). With Los Angeles’ O-line banged up, the Niners’ ability to keep pressuring Stafford through all four quarters will shape this game — especially because of the Niners’ complementary ability to execute quick, effective passes on offense that exploit physical mismatches at the linebacker and safety level.

Against the Rams’ imposing pass rush, Kyle Shanahan has drawn up a quicker passing game plan for Jimmy Garoppolo. When facing Los Angeles this season, Jimmy G’s average time to throw was 2.37 seconds, while 62.7 percent of his throws were quick passes — and he was under pressure on just 21.8 percent of dropbacks. Against all other opponents in 2021, his average time to throw was 2.71 seconds, while just 44 percent of his throws were quick passes, and he was pressured on 25.7 percent of dropbacks. And the Niners have had more success on quick passes against the Rams than other opponents have. Against San Francisco, the Rams faced quick passes on 61.5 percent of throws with 6.3 air yards per attempt while allowing 9.1 passing yards on average and a 110.3 passer rating. Against all other opponents, the Rams faced quick passes on 52.3 percent of attempts, allowing 4.0 air yards per attempt, an average of 6.3 yards per throw and a 93.5 passer rating. It’s not like Garoppolo leans on play-action against L.A. While he has excelled with play-action in general, generating the best completion percentage (75.4) and most yards per attempt (10.5) on play-action passes against all opponents in the NFL during the regular season, his numbers when not using play-action against the Rams, going back to 2019, (73.5 completion percentage, 8.8 yards per attempt, 4.4 completion percentage over expectation) are much better than they are against all other opponents (65.3 percent completion rate, 7.4 yards per attempt, -1.1 CPOE).

Here’s how this all works together: It’s not just quick-release passes that matter, it’s also about what kinds of passes those are and to whom they are going (ahem — Deebo Samuel, who ranks fifth in the NFL this season, including playoffs, in receiving yards on quick passes with 639, is a huge factor here). In San Francisco’s Week 18 comeback, the Rams’ defense did not adjust to the Niners’ halftime offensive adjustments, and then their defense kept consistent pressure with four, which resulted in their OT triumph, pointing to another potential advantage against a Rams defense that was similarly slow to respond to the Bucs’ halftime offensive adjustments last week.