Denver Broncos 2015 Year in Review: A Dominant Defense Leads to a Championship

Whatever a team’s faults might be, it’s difficult to find ways to be overly critical of any NFL squad that successfully navigates the treacherous regular season and the unpredictable playoffs to end up hoisting the Lombardi Trophy.

The Denver Broncos finished the season not only as Super Bowl champions but also with the best overall defense as well according to our metrics here at numberFire -- and it wasn’t even particularly close.

And while the Denver defense was ultimately the biggest factor in securing the third NFL championship in franchise history, what may be even more impressive is that they did so with not much help on the opposite side of the ball.

Let’s take a deeper look into how Denver made their way to Super Bowl 50 and dispatched of the Carolina Panthers to become world champions.

What Went Right

I know you’re probably aware of how amazing the Broncos’ defense played this past season. I’d probably be better off trying to surprise you by pulling something out of left field, but it wouldn’t really be fair. 

As I mentioned above, the Broncos finished the season with the best defense according to numberFire metrics, with nearly twice the Adjusted Defensive Net Expected Points (NEP) mark of the next closest team, Carolina.

In fact, their -0.07 Adjusted Defensive NEP per play was the fifth best mark of any team since 2010.

Simply put, they stifled nearly every single opponent they faced in 2015.

Allowing 18.5 points per game, and 30 or more points in just one game (Week 14 against Pittsburgh), the defense held them in every game even when the offense sputtered.

As expected, the duo of Von Miller and DeMarcus Ware proved to be hellish for opposing offensive lines, combining for 18.5 sacks, 5 forced fumbles, and 4 fumble recoveries.

Another dynamic defensive duo was the cornerback pairing of Chris Harris and Aqib Talib. 

Linchpins in a secondary that allowed just 199.6 passing yards per game -- best in the league -- and only five passing plays of 40 yards or more -- tied for first -- they provided a trustworthy back end for Denver’s aggressive pass rush.

Emmanuel Sanders was arguably Denver's most efficient offense player, ranking 19th in Reception NEP on a per-target basis among the 32 wide receivers with 100 or more targets. Overall though, we should reserve our discussion regarding the Broncos' offense for the next section.

What Went Wrong

It’s hard to believe that an offense that had ranked first and second in Adjusted Offensive NEP per play during the 2013 and 2014 seasons could fall as far as they did in 2015.

Sure, Peyton Manning is old. And yeah, Denver’s offensive line played at a much lower level than in previous seasons. But considering the talent level still on the roster, the Broncos were extremely disappointing.

Ranking 30th in overall offensive efficiency according to our schedule-adjusted metrics, there was plenty of blame to go around.

2015 was Manning’s worst season of his career in terms of Passing NEP, Passing NEP per play, and Passing Success Rate -- the percentage of plays that positively affect a player's NEP metrics. It was the only time during his 15-year career he finished with a negative Passing NEP per play score (-0.02).

And while Brock Osweiler did play substantially better than Manning in his seven starts, he ranked just 21st in Passing NEP per play among the 37 passers with 200 or more drop backs.

The below-average quarterback play spilled over to Demaryius Thomas's performance, who -- despite posting 105 catches, 1,304 yards, and 6 touchdowns -- offered the least efficient season on a per-target basis of his career:

What's to Come

Like I said earlier, I don’t want this review to come off overly-negative. The Broncos did win the Super Bowl, after all.

But with Peyton Manning’s career seemingly done -- whether literally or figuratively -- and just $11 million in available salary cap per Spotrac, there’s work to be done to secure back-to-back titles.

The team did decide to franchise tag Von Miller, but there are still questions left to be answered.

Manning is set to make $21.5 million next season, making his offseason decision-making even more crucial.

Picking 32nd in this year’s NFL Draft, the Broncos will likely stack depth at key positions, especially along the offensive line. Taking a quarterback at some point is another obvious way to go.

All things considered, we should expect Denver to be in the AFC title conversation in 2016. Assuming the defense stays the course and if the offense even improves marginally, Broncos’ fans will likely be rooting on their team into the early part of 2017.