We're into the final stretch of the 2021 NFL regular season. and for this week's edition of "Thursday Night Football," we have the San Francisco 49ers paying a visit to the Tennessee Titans.

Both San Francisco and Tennessee hold playoff spots at the moment, with the 49ers occupying the No. 6 seed in the NFC and the Titans holding a narrow lead in the AFC South. Those spots are not necessarily safe, though, with multiple teams within shouting distance. 

As with any game this late in the year, this one is rife with postseason implications. That, plus the potential for fireworks based on the stars who will be (and could be) on the field, should make it fun to watch. As for what will happen, we'll find out later this evening. For now, though, let's break down the matchup.

How to watch

Date: Thursday, Dec. 23 | Time: 8:20 p.m. ET
Location: Nissan Stadium (Nashville)
 Fox/NFL Network | Stream: fuboTV (click here)
Follow: CBS Sports App
Odds: 49ers -3, O/U 44

When the 49ers have the ball

We've written at length about the 49ers offense a couple times this year, and not much has changed since the last time we did. The most creative thing they're doing right now is utilizing Deebo Samuel as a hybrid wide receiver/running back. (Below is an excerpt from our recent story on emerging run games, with updated numbers.) 

Samuel, honestly, is a player that makes absolutely no sense. Through Week 8, Samuel ranked second in the NFL in receiving yards behind only Cooper Kupp. He's basically been playing running back for the last six weeks, and he still ranks second in the NFL in yards per route run among the 168 players who have run 200 routes or more. And yet he might somehow be an even better rusher than he is a receiver. He has 39 carries for 269 yards and seven touchdowns on the season, with 33 for 247 and six over the last five games. 

The Niners will line up him in (or motion him into) the backfield and use him as a regular running back, running toss, inside zone, power, split zone, and more. And it all works just the way it would if they had lined up Elijah Mitchell, Jeff Wilson Jr., Raheem Mostert, or any one of their other various backs behind Jimmy Garoppolo. The way moving Samuel into the backfield allows them to shift their other skill position players into different alignments throws defenses into chaos, and turns regular run plays into seemingly unstoppable ones. 

The Niners have also been spamming one particular play with Samuel in the backfield, while playing around with how they block it up by utilizing shifts and motions and different skill-position alignments. Samuel will line up or motion next to Garoppolo in the shotgun and take a handoff, but rather than executing an inside give like most handoffs from the gun, Garoppolo reverse-pivots just like he would from under center, and the play turns into an outside handoff instead. Defenses are completely flummoxed by this action. 

Jeff Wilson Jr. is filling in for rookie Elijah Mitchell, forming the power component of the run game. The success those two have behind a strong run-blocking offensive line is what allows Kyle Shanahan to minimize the work that needs to be done by Jimmy Garoppolo. (Below is an excerpt from an early-season story on Garoppolo, with updated numbers.) 

The idea the 49ers have sold is that they have an elite offense whenever Garoppolo is healthy and under center. They ranked seventh in Football Outsiders' offensive DVOA when he started all 16 games in 2019 and check in fourth so far this year. But it sure doesn't seem like Garoppolo is the one leading them to those results. And if the Niners felt he was, they surely wouldn't be designing an offense that asks so little of him. 

Case in point: 19% of Garoppolo's passes this season have been thrown to receivers at or behind the line of scrimmage, per Tru Media. Meanwhile, only 8.3% of his attempts have traveled 20 or more yards in the air, the league's fifth-lowest rate. As such, Garoppolo is averaging just 7.5 air yards per attempt, the 10th-lowest mark among 32 qualified quarterbacks. His pass attempts have, on average, targeted pass-catchers 1.9 yards short of the sticks, the fifth-lowest mark in the league. Despite all this, he's thrown into tight windows on 16.8% of his passes, 12th-highest among the same group of players. 

None of those are necessarily indicators of a team that trusts its quarterback to be the driving force of the offense, though the final one is an indicator that he might be trying to force throws despite the scheme making things easy on him. According to data from Pro Football Focus, for example, Garoppolo has one of the lowest "big-time throw" rates among NFL starting quarterbacks, along with one of the highest "turnover-worthy play" rates. 

Luckily, the 49ers have a group of playmakers so diverse and explosive that they don't actually need Garoppolo to do all that much more than play point guard. (He's doing it quite well at the moment, but still not getting much more than what is schemed up for him.) Getting the ball into the hands of Samuel, George Kittle, or Brandon Aiyuk is enough. Those guys can do the rest. Tennessee is stronger against the run than the pass, so it'll be interesting to see how much the Niners put on Garoppolo's plate Thursday evening. Do they try to attack down the field, or stick with what's been working in recent weeks? 

When the Titans have the ball

The Titans' offense has essentially fallen apart in recent weeks. The absences of Derrick Henry, A.J. Brown, and Julio Jones are simply too much to overcome. 

The Titans were the rare team who could base their entire offensive attack around the running game and actually have it work. Once Henry went down, pivoting to a pass-based approach with Ryan Tannehill finding Brown and Jones down field would have made sense; only the wide receivers haven't been able to stay on the field. One or both may be back on Thursday night, but it's tough to count on them to play for an extended stretch given the way this year has gone. It seems extremely likely that Jones' snaps will be limited if he suits up. If Brown is activated off injured reserve in time to play, getting on the field for somewhere between 60 and 80 percent of snaps seems the most likely outcome. He's exceeded 80 percent in only five games this year. 

That means the Titans will again be forced to lean on the likes of Chester Rogers, Nick Westbrook-Ikhine, Cody Hollister, and their cadre of tight ends for more snaps than any offense should be comfortable leaning on those guys. 

Tennessee would likely still prefer to make things work on the ground, distributing touches between D'Onta Foreman (looking surprisingly frisky after all these years), Jeremy McNichols, and Dontrell Hilliard. It's not the most imposing group of running backs in the league but Foreman, in particular, has shown an urgency in getting north and south that could cause some teams problems if they don't match Tennessee's level of physicality up front. 

The 49ers, though, rank fourth in the NFL in Adjusted Line Yards allowed per carry, indicating that they're doing a strong job of winning the battle along the lines. They've stopped 20 percent of opponent rushing attempts at or behind the line of scrimmage, per Football Outsiders, the seventh-best mark in the league. 

The pick

It's far more advantageous to attack the Niners through the air. It's just not entirely clear that the Titans will be able to do so, given the way they've performed in recent weeks and the questions surrounding the health of their key passing-game contributors. 

Prediction: 49ers 27, Titans 17