AFC Championship Preview: The Final Chapter of a Historic Rivalry?

Tom Brady and Peyton Manning are going at it in the playoffs once again, maybe for the last time. What should we expect?

Well all know the big storyline in this one. 

For the umpteenth time, it's Tom Brady versus Peyton Manning. These two have already played 16 career games against each other, including four playoff contests. The Patriots have won 11 of the matchups, but the playoff series is at 2-2. 

The thing about this one, though, is that the quarterback duel no longer deserves center stage.

This time, the spotlight should be on the Broncos defense, the best in the league, against Tom Brady, who is still playing some of the best football of his career at 38 years old. There's no shortage of intrigue on the other side of the ball, either. Manning is looking to make one last surge -- hopefully erasing the memory of what has been a poor season -- against an occasionally shaky Patriots' defense.

Brady's Offense

Let's start with Brady and the Patriots' offense. Our Net Expected Points (NEP) metric (which you can read more about in our glossary) measures how many points a team gains or loses compared to expectation on any given play. When adjusted for strength of schedule, the Patriots offense ranked third in NEP per play, ranking third in Passing NEP per play and 10th in Rushing NEP per play.

While it ended up happening kind of quietly (partially because of his weakest stretch of games coming late in the season, and partially because of Cam Newton and Carson Palmer making MVP pushes), Brady once again put together an incredible season. His 36 passing touchdowns lead the NFL, while his 7 interceptions were the second fewest for a season in his career. His 5.8 touchdown-interception ratio was also the best in the league. Among the 37 passers to record 200-plus drop backs on the season, Brady ranked fourth with a 0.25 Passing NEP per drop back.

This Broncos' defense isn't going to be scared off by the gaudy numbers, though, and Brady is going to be in for a tough day. Denver ranked first in schedule-adjusted Defensive NEP per play, while finishing first against the pass and fifth against the run. Their -0.07 Defensive NEP per play makes them the fourth best defense of the last five seasons, and that's not accounting for better offensive play in 2015 than those previous years.

Denver gets after the quarterback better than any other team in the league, averaging a sack on every 12.24 opponents' drop backs, the best mark in the NFL. They have five different defenders with at least five sacks on the year, led by Von Miller's 11.

They've only given up 300-plus passing yards in two games this year (both against Ben Roethlisberger), and have held opposing offenses to two or fewer passing touchdown in all but two games.

There's some room for concern in the Denver secondary, though, as Chris Harris, their top corner, is playing through a fairly serious shoulder injury. He's expected to play on Sunday, but the injury will limit him, and head coach Gary Kubiak said that Harris is playing "with one arm, in a lot of ways."

If Harris isn't on top of his game, look for Julian Edelman to give the Broncos fits. I looked earlier this week at just how valuable Edelman is to the Patriots' offense, and the short answer is "very." His 16 targets were the most in the league last week, and with 10 catches for 100 yards, Edelman seems to be back at full strength. With such a dangerous pass rush across from Brady, expect Edelman to play a big role this week, with lots of quick pass plays designed to get the ball out before the pass rush gets home.

Another name to watch in the Patriots' passing game will be James White.

White had a phenomenal season as a receiver, producing a 0.70 Reception NEP per target. There have been 204 50-plus target seasons for running backs in the last decade, and White's 2015 is the third-most efficient in that group. He only saw three targets last week, but we can expect him to play a bigger role as an outlet for Brady when Denver's pass rush inevitably gets in his face.

And, of course, you can't talk about the Patriots' passing offense without talking about Rob Gronkowski. Gronkowski scored double-digit touchdowns this season, which his fifth time doing that in six seasons as a pro. His 0.88 Reception NEP per target ranked second among tight ends with at least 40 targets this season, and he had a big game in the Patriots' first outing against the Broncos this year, catching six passes for 88 yards and a touchdown.

It's also not looking like the Patriots are going to try doing much damage on the ground this week. With White (whose -0.17 Rushing NEP per carry was one of the worst in the league) and Steven Jackson as the team's top running backs, they leaned heavily on the pass game last week. They ran the ball only 14 times, with Tom Brady seeing 6 of those carries. The Broncos have been great against the run this year, holding their opponents under 100 rushing yards in 10 games, and under 50 yards in 4 games, but they'll likely go largely untested this weekend.

Manning's Offense

While it will be powerhouses slugging it out when the Broncos are on defense, when they have the ball, it will be about Manning trying to come back from his terrible season and put together a strong enough performance to reach one more Super Bowl.

The Broncos offense ranked only 28th according to our metrics this year, finishing 25th in passing and 27th in rushing. The Patriots defense didn't match the production of their offense, but were decent, ranking 15th against the pass, 12th against the run, and 12th overall.

To avoid mincing words, Peyton Manning's 2015 season was terrible. For the first time since his rookie year, he threw more interceptions than touchdowns, and it wasn't even close, with 9 touchdowns and 17 interceptions through 10 games, good for only a 0.53 touchdown-interception ratio (the ratio for his career is 2.15). 

Manning posted a -0.02 Passing NEP per drop back, ranking 32nd among the 37 quarterbacks with at least 200 drop backs this season. When he missed time due to injury, he was outshined by Brock Osweiler, who ranked 22nd with a 0.08 Passing NEP per drop back, and who might actually give the Broncos a better chance at winning this game if he were starting. Every 10 dropbacks that Osweiler took this year produced, on average, a full point compared to expectation versus 10 Manning drop backs.

While the Patriots' defense only just finished in the top half against the pass this year, they don't exactly make things easy on quarterbacks. They are second only to the Denver defense, recording a sack every 13.14 opposing drop backs, and the pass rush is lead by an incredibly talented Chandler Jones, who had 12.5 sacks in the regular season (and added one last week against the Chiefs). Jabaal Sheard has also made a big impact in his first season in New England, recording 8.0 sacks, and often lining up as an interior rusher on passing downs, and area the Patriots had been weak in past years.

If Manning does manage to get things going this week, he has the weapons to do serious damage. While Demaryius Thomas and Emmanuel Sanders both had quiet, inefficient seasons, a big part of that was poor quarterback play. They both finished 2014 in the top-25 in Reception NEP per target (minimum 50 targets), and Thomas ranked seventh in 2013.

The Patriots' secondary is led by safety Devin McCourty, and last year's Super Bowl hero Malcolm Butler. Butler has developed into one of the better coverage corners in the league, and has succeeded despite often being tasked with shadowing opponents' top wideouts.

Not providing any relief from the struggles throwing the ball, Denver also had a poor season on the ground. Though both Ronnie Hillman and C.J. Anderson saw over 150 carries on the season, neither produced well. They ranked 40th (Hillman) and 41st (Anderson) in Rushing NEP per carry among the 72 backs to record at least 50 carries on the season.

While Hillman was terrible last week, running the ball 16 times for 38 yards and putting up an abysmal -3.62 Rushing NEP, Anderson showed signs of what had people excited about him from last year, seeing 15 carries for 72 yards and a touchdown with a 0.88 Rushing NEP. If you had to put money on of the backs spearheading a successful running game, it would be Anderson.

Anderson's success last week came against the fourth-ranked Steelers run defense, and he might be the key for the Broncos on offense. Linebackers Dont'a Hightower and Jamie Collins have both been limited in practice this week, and while they're expected to play, the Patriots two best linebackers (and two of their best run stoppers) being slowed down at all could give Anderson the edge he needs to put up a big game.

Who Wins?

Wherever you look, this game provides intriguing matchups, and the deeper you get into the playoffs, the more unpredictable things can get. numberFire Live has Denver as the slight favorites this week, with a 52% chance at making it to the Super Bowl. Betting oddsmakers have it the other way, and New England is three-point favorites according to betting odds. There have been some incredible games already in this year's playoffs, and we shouldn't expect anything less from this one.