You have not seen this Broncos-Patriots matchup before. Yes, you’ve seen as many as 14 games between Tom Brady and Peyton Manning, in just about every combination of time of year, meaning, relative team quality, and weather possible. You’ve seen Denver and New England match up regularly in the playoffs; after Sunday, three of Denver’s seven most recent playoff games will have come against the Patriots. You’ve even seen these two teams play earlier this season, in a classic that saw the Patriots booed off the field by their fans at halftime before erasing a 24-0 deficit and winning, 34-31, on the fortuitous bounce of a punt. Those Broncos and Patriots might vaguely resemble the teams you’ll see contest the AFC Championship Game this weekend, but they’re not these teams and they’re not playing this game.

This isn’t some rhetorical argument about the difference between the regular season and the playoffs; it’s an acknowledgement that the game you saw between these two teams in Week 12 was affected by a number of elements that either won’t appear in Sunday’s game or will after not showing up in late November. And no, Manning’s arm strength isn’t one of them. What might be most interesting, though — and most telling about who will prevail this weekend — are those few factors that do seem likely to show up again.

You remember that first game, right? I wrote a long recap of it, but the tl;dr version is this: Patriots turn the ball over a bunch, Broncos score off all those turnovers, Broncos have a 96 percent win expectancy at halftime, Broncos turn the ball over a bunch, Patriots score off all those turnovers, Broncos tie it up, Bill Belichick takes the wind in overtime, a punt bounces off a Bronco, Patriots win. Obviously, it seems unlikely these teams will turn the ball over a combined seven times again, and it’s even more unlikely they’ll evenly split the turnovers so all the Patriots’ lost possessions are in the first half and the Broncos are responsible for all the turnovers in the second half. Let’s start there.

The Air Up There

There are other notable differences with the game itself. For one, it’s being played in Denver, not Foxborough. That changes some of the decision-making and relative strengths of each team, notably because of the thin air and the higher elevation in Denver. Those changes seem to favor the Broncos. The elevation usually means more substitutions for some of the game’s larger players, especially among the players on road teams who aren’t used to the conditions. During the first game between these teams, five members of the New England defense managed to make it through each of the game’s 90 snaps: starting safeties Duron Harmon and Devin McCourty, and defensive linemen Chandler Jones, Chris Jones, and Rob Ninkovich. That’s unlikely to reoccur in Denver. Consider that just one defensive lineman — Chiefs nose tackle Dontari Poe — managed to play every single down as a visiting player in Denver this year, with Oakland’s Lamarr Houston the only other defensive lineman suiting up for more than 82 percent of his team’s snaps. Injuries have left the Patriots razor-thin on defense, and in a typical Patriots game, even that 82 percent participation rate would mean that New England would swap out a critical component like Ninkovich for Andre Carter or risk having a gassed pass rush during long Manning drives.

The thin air also levels the playing field in terms of Denver’s biggest weakness on special teams: kickoffs. While Matt Prater had an excellent regular season in terms of kicking field goals before missing one (nearly two) attempts last week, both he and the remainder of Denver’s kickoff coverage unit struggled when kicking off, perhaps owing to the exhaustive strain placed on them by one of the greatest offenses in league history. The Broncos allowed a league-leading 29.3 yards per kick return this season, and the third-worst Lions were just about closer to league-average than they were to the Broncos. Football Outsiders, after adjusting for the thin air of Denver and the expected field position produced by each kick, pegged Denver’s cumulative kickoff performance as worth minus-11.7 points of field position, the fourth-worst in the league. The good news? It’s hard to return kickoffs when they’re booted into the second row. On the road, just more than 58 percent of Prater’s kickoffs resulted in touchbacks; at home, more than 84 percent of Denver kickoffs resulted in touchbacks. The Patriots, meanwhile, had the league’s second-best kickoff performance, with Stephen Gostkowski & Co. worth 10.5 points of field position; that’s typically an advantage, but in Denver, the difference between New England’s typical field position on kickoffs and the opposition’s should be neutralized.

What’s that? You want to talk more about average starting field position? Me too! In the first game, the difference in average starting field position between the two teams was an average of five yards, which rose to six yards if you only considered possessions that began on kickoffs. Those numbers were also notably affected by the wind, which was listed at 22 mph at kickoff and remained at about 20 mph throughout the game, per NBC’s in-game graphics. The wind was meaningful enough that Belichick chose to take the wind after winning the overtime coin toss as opposed to receiving the football. It materially affected both teams’ downfield passing games and their decisions around the edges of each kicker’s field goal range, especially with the Broncos in overtime. That’s not going to be a factor Sunday; the Denver forecast calls for winds of 9 mph and, if you’re concerned about Manning’s ability to execute in cold weather, a high of 58 degrees.

Left and Leaving

As for the teams themselves? Well, they’re not bringing along a full complement of talent, as both the Broncos and Patriots have been losing key players all season, like they’re trying to beat The Oregon Trail without feeding anybody along the way. Key contributors like Ryan Clady and Vince Wilfork were lost early on, but despite the first Broncos-Patriots game taking place only eight weeks ago, a number of players who changed that game won’t appear in this one, and vice versa.

The biggest absence for the Patriots, obviously, is tight end Rob Gronkowski. He had seven catches for 90 yards during the first game, with those catches often coming in the exact moments when you would expect Gronk to make a difference: in the red zone and on third down. He was the only Patriots player who could reliably beat man coverage, and he gave New England its best weapon on either side of pick plays. Gronk was also a key blocker in both pass protection and the running game. Aaron Dobson and Kenbrell Thompkins were also regulars, and they might not be healthy enough to play Sunday.

That running game is the focal point of the Patriots’ offense post-Gronkowski, but its stars didn’t see much of the field in Week 12. Stevan Ridley started at running back, but after fumbling in the middle of a spin move in the first quarter, he was benched for the remainder of the contest. He was replaced by LeGarrette Blount, who fumbled after a helmet-to-helmet hit and did not return. The two backs combined for six carries. During New England’s past two games, they’ve combined for 74 carries, producing 481 yards in the process.

The game situation and the total lack of confidence in its power backs prevented New England from running the ball much during the first game. Its recent game plans suggest it will place more of an emphasis on the run this time out, and it may get some help from a beaten-up Denver defense. The Broncos will be missing what might be the three best players in their front seven this time around, with defensive linemen Kevin Vickerson and Derek Wolfe and star linebacker Von Miller all on injured reserve. Miller had an impressive game in Week 12, blowing by Patriots left tackle Nate Solder for two sacks while pushing Solder into the backfield on a number of running plays. Denver needs somebody — likely Shaun Phillips — to step up in Miller’s absence and bother Brady. Phillips had two of Denver’s four sacks last week, when it took advantage of backup right guard Johnnie Troutman and rookie right tackle D.J. Fluker to get to Philip Rivers. It will try to do the same thing with inexperienced right tackle Marcus Cannon on Sunday, while the Patriots pick at a thin, inexperienced defensive line with Blount.

A hidden injury in that game came on the final play of the first half, when Brady threw up a Hail Mary that fell well short of the end zone. Dominique Rodgers-Cromartie injured himself on that play and did not return, which cost the Broncos their top cover cornerback just before the Patriots launched a comeback around their passing game. During that second half, Brady was able to take advantage of the likes of Quentin Jammer and Kayvon Webster, who filled in for DRC. The good news for the Broncos is that Rodgers-Cromartie is back … but the bad news is that his battery mate in the secondary, Chris Harris, tore his ACL last week and is done for the year. The Broncos have Champ Bailey (absent in the first game) playing in the slot for the first time in his career, and he certainly has the muscle memory to play on the corner, but the Patriots already line up their best receivers (Julian Edelman and Danny Amendola) in the slot, and Bailey isn’t in the game shape to play on an every-down basis at this point. Jack Del Rio and John Fox will choose between Bailey, Jammer, and Webster, but the decision doesn’t really matter; whoever it is, Brady’s going to try to pick on him.

Oh, speaking of Fox, he’s back, too. The Denver head coach missed the first game between these two teams after undergoing a heart procedure in November. He might have had some input creating the game plan at the time, and Fox isn’t known as a particularly excellent in-game coach (his challenge logic is notably lacking), but his presence in the film room and as a defensive coach has to help Denver, especially since it helps free up some of the responsibilities that Del Rio had to assume as the de facto head coach and defensive coordinator the first time these two played.

The Patriots’ defense, of course, isn’t doing much better. I covered New England’s defensive injury woes last week, and they’re not getting any healthier, as linebacker Dont’a Hightower was listed as questionable on the injury report this week. The Patriots had run-stopping middle linebacker Brandon Spikes for that Broncos game. He’s now on injured reserve. New England does have safety Steve Gregory in the lineup, who missed that Broncos game and was replaced by rookie Duron Harmon. Harmon played every snap and was a little overwhelmed by the action, with Manning making sure to go after him when he got matched up in coverage against Jacob Tamme. The Patriots will have a better safety in that sense for covering tight ends, but the Broncos will also have a better tight end, since Julius Thomas missed the first Broncos-Patriots game and will be in the lineup Sunday. Expect to see a combination of Gregory, Jamie Collins, and some McCourty on Thomas. Manning will hope to pick on Kyle Arrington or Logan Ryan (who had an interception in the first game) in the slot against Wes Welker.

Born Into Run

The biggest reason why this game isn’t likely to resemble a typical Brady-Manning contest is because the nature of the two teams doesn’t lend itself to such a game. For the first time in probably the entire history of this epic feud, both these quarterbacks are the point men for offenses that are better off running the ball than they are passing.

That’s not a very controversial statement for Brady’s Patriots, given the way his receiving corps has collapsed over the past 12 months. The Patriots will go out of their way to incorporate Shane Vereen into the passing game, including splitting him out as a receiver if they can match him up against linebacker Wesley Woodyard or safety Duke Ihenacho in man coverage. They love to run slants and other clearing routes to create space across the middle of the field while Vereen runs an angle route out of the backfield against an overmatched man defender or a distracted linebacker in zone coverage. Otherwise, New England is basically down to Edelman, a limited Amendola, and replacement-level talent at receiver, which is scary considering Edelman was the sixth option in the passing game a year ago. Then again, Edelman is just fine if you have a quarterback who can throw a passer open and a defense that gets lost against a two-man route with four defensive backs and two linebackers dropping into coverage.

You can watch the full play here. Edelman is double-covered and shouldn’t ever get open, but he scares deep safety Mike Adams enough with his speed to get Adams to turn his back, at which point Edelman breaks off his route and runs an out away from the trailing defender, Harris. The Broncos have two other defenders on Gronkowski, the other receiver in the route, and two linebackers at the line of scrimmage who aren’t green-dogging and blitzing, perhaps out of fear that the Patriots — blocking with eight men — will send some blockers out into patterns. Gronk won’t be around, but the Broncos can’t triple-cover Edelman, can they? At some point, their defense has to make plays.

That pass comes off play-action, where I suspect the Patriots will make most of their hay on Sunday. Their running game has been too good the past couple of weeks, and with the injuries, Denver’s run defense isn’t likely to be great. Think of it through the prism of Brady’s tight ends. Over the past few years, Brady has been in a pass-happy attack that’s been built around tight ends who can catch, Gronkowski and Aaron Hernandez. Now, Brady’s tight ends are block-first guys, Michael Hoomanawanui (who also missed the first game) and Matthew Mulligan. You can see their impact at the point of attack on this Ridley touchdown run from last week, where they line up next to each other on the right side. They double-team Erik Walden at the line of scrimmage and ride him out of the play before Mulligan gets off the double-team to keep Antoine Bethea away from the hole. On Ridley’s second touchdown, the Patriots just run right behind Hoomanwanui, who moves Walden— signed by the Colts for his ability to set the edge — off the edge before finishing with a pancake.

As Robert Mays noted in Wednesday’s piece on legendary New England offensive line coach Dante Scarnecchia, the Patriots have been shockingly run-oriented over the past couple of weeks. Mays found that there have been only five games in the Belichick era in which the Patriots ran the ball 40 or more times while throwing it 25 times or fewer, and two of those five examples have been New England’s last two games. Brady had been a part of only two such games before the last two weeks, and neither of them had occurred since the Patriots really adopted the spread approach in 2007. Some of the run totals have been dictated by the scoring situation, so don’t expect the Patriots to keep pounding the rock if they’re down by 21 points in the first half again, but it seems likely New England will try to use the same run-heavy approach against Denver while mixing in targets against the weaker points in that secondary.

It’s not quite as clear that Denver’s strength is running the football, but in this matchup, it should be. The Broncos absolutely annihilated the Patriots on the ground the first time these two played, primarily on the legs of Knowshon Moreno. Denver’s starting tailback ran for 224 yards on 37 carries, averaging 6.1 yards per pop with a long carry of just 18 yards, which tells you how consistently effective he was. Of Moreno’s 37 carries, 11 went for first downs and 24 went for four yards or more, with just one carry producing negative yardage. Moreno was particularly dominant in overtime, busting off a pair of 18-yard runs that helped push a sputtering Broncos passing attack up the field against Belichick’s chosen wind, but he aggravated an ankle injury that took away his burst on Denver’s final drive. The Broncos then had to turn to C.J. Anderson, as rookie Montee Ball had been benched after fumbling on a third-quarter checkdown. Ball is back in the rotation now, and he and Moreno should be able to gash a Patriots front seven that is now without its best run defender, Spikes, after having him in the first contest.

I’m not even really sure what Belichick can do, to be honest, beyond hoping that his players perform better. He knew what was coming, and I’m sure his players did too. The Patriots just couldn’t stop Denver on the inside zone, a staple of the Manning offense going back to Indianapolis. Chris Brown, as you might expect, has written an excellent little breakdown of the inside zone and outside zone, with really useful videos of the University of Minnesota offense running it during the days of Marion Barber and Laurence Maroney here. On the inside zone, instead of a more typical blocking assignment that sees linemen trying to seal defenders on either side of a hole, you’ll see an entire offensive line blocking to the side where the play was called. If the run is designed to be behind the left guard, everybody blocks to the left side. That allows a back to sniff out a cutback lane, and when the Broncos run this out of the pistol (as they often do), Moreno is ruthlessly effective at finding that crease and sneaking through it for a nice chunk of yardage.

Denver was very comfortable running inside (and outside) zone during the first game, even without Thomas around. It turned a weakness into a strength by using Virgil Green, Denver’s blocking tight end, on wham blocks coming across the formation to cut off any backside pursuit from the opposing end. In a way, this is using Belichick’s own coaching against him; Belichick teaches his ends to stay disciplined in their running lanes and avoid overrunning a play, especially against a team that might very well be running play-action and using the aggressiveness to their advantage like Denver, but that also prevents them from beating the wham block of Green. Of course, Green is a better blocker than Thomas, and it remains to be seen whether Denver will sacrifice Thomas’s receiving ability to get Green into the lineup. He played 56 snaps with Thomas out against the Patriots in Week 12, but against the Chargers last week, Green played just seven offensive snaps.

NFL Network’s Albert Breer noted before the Colts game that the Patriots had been drilling hard against the inside zone, but there’s only so much they can do if Denver executes well. The Patriots are starting two cast-off defensive tackles, a backup middle linebacker, and a backup outside linebacker. Denver’s offensive line took a hit without Clady, but its interior three of left guard Zane Beadles, center Manny Ramirez, and right guard Louis Vasquez remains a strength. The Patriots have to win up front and prevent Denver’s line from beating them up-and-down, one-on-one, which will allow those inexperienced linebackers to diagnose and make plays properly without getting caught up in the trash at the line of scrimmage, as Hightower and even Harmon did too frequently during the first contest.

If that weren’t enough, the Broncos are also hopping on an NFL bandwagon. Packaged plays are all the rage in the NFL, and while the Broncos haven’t exactly been like Chip Kelly or Marc Trestman in implementing them, they’re sprinkling a few options into the Manning offense as the season goes along, with a couple of packaged plays showing up against the Chargers last weekend. Most of those come with the Broncos running their typical inside zone or outside zone up front with some sort of screen built in. That manifested itself in something as simple as leaving a split-out Eric Decker at the line of scrimmage for a possible quick hitch and, in the more exotic variety, this Trips Bunch set, where Moreno has just been handed the ball while Demaryius Thomas falls behind the two other blocking receivers in the set for a possible screen pass, as you can see in the GIF below:

That I’ve gotten this far without really mentioning the guy who tore up the passing record book this year is kinda scary. To be honest, Manning doesn’t need my introduction, nor does he need the help of mixing in a packaged play to create an easy throw. It’s just kinda terrifying to see the Broncos adding to and improving an offense that might have been the best the game’s ever seen, you know? Barring a surprise, the Patriots will line up Aqib Talib on Demaryius Thomas around the formation, a matchup that saw Thomas catch four of the nine passes thrown to him for 41 yards and the game-tying touchdown last time out. If Talib can do that again Sunday, given his recent woes, the Patriots would likely take it. Of bigger concern is somehow getting some combination of linebackers (notably Collins and Hightower), cornerbacks (Alfonzo Dennard, Ryan, and Arrington), and safeties (Gregory and McCourty) to slow down Decker, Welker, and Julius Thomas. It’s a tall order.

It All Comes Down To …

The New England passing game. I’m confident both these teams will be able to run the football effectively. It seems reasonable to suggest that Manning will, at the very least, be in charge of a pretty good passing attack. So, then, can Brady match the Denver passing attack throwing to his motley crew of receivers? After the Gronk injury, he posted one heavy-volume game against the Dolphins followed by three mediocre performances, in which he has completed less than 55 percent of his passes and averaged just 164 passing yards per contest. I can’t see the Patriots winning with that little from Brady. If the Patriots can exploit a weakened Broncos secondary, well, it might just come down to who gets the ball last.