It’s no secret the Denver Broncos defense carried the team for the last two seasons. Their Super Bowl 50 victory was the ultimate reward for a spectacular defense. However, their DVOA finish of 1st in 2016-17 still wasn’t enough to get to them to the playoffs last season. The hard truth is, if Broncos defense slips in DVOA, we may be looking at another dismal season.

It’s tempting to dismiss Football Outsiders, but they’ve proven themselves accurate more often than not.

In 2015, DVOA pegged Broncos defense as first in the league and offense as a shameful 25th.

In 2016, DVOA pegged Broncos defense as first again, but offense was an even more abysmal 28th.

And the Broncos missed the playoffs.

Best case scenario

If you can call it that. The team had hopes for the offseason that involved their 2016 first-round pick Paxton Lynch to develop as a quarterback and be a reliable backup to starter Trevor Siemian. He would’ve provided an added dimension to an otherwise mediocre unit.

Lynch did not develop. He wasn’t any worse… but he wasn’t much better. Now with an injured right shoulder, Siemian is back under center with Brock Osweiler as his backup.

Beyond quarterback issues, Denver’s offense remains their biggest sore spot. GM John Elway was well aware of the severity of the situation and promised former Dallas Cowboys guard Ronald Leary $24 million. Drafting Utah offensive tackle Garett Bolles 20th overall was the second trick up his sleeve.

With these two acquisitions in mind, the only place for the Denver’s offense to go is up. It is just too unlikely that they can get any worse. An improved running game and Siemian playing better will push Denver up away from the bottom four in the league.

Worst case scenario

Denver’s defense finished first in DVOA two years in a row, and will return almost completely intact. But according to The Ringer’s Robert Mays it’s not necessarily the players who make all the difference, but the quality of the coaching. “The maestro of this group, defensive coordinator Wade Phillips”, is now in Los Angeles, doing the same job.

“Denver was excellent on defense before Phillips arrived, and it will likely stay excellent after he’s gone. But there’s an important distinction between being the league’s best unit and being one of the best in the league.”

If the Broncos defense slips even just a few places – say, to fifth – Denver could spiral downwards from a 9-7 team to a 6-10 team. Which is why the offense absolutely must improve. With Al Woods taking over from Phillips and new head coach Vance Joseph, we can only hope they can maintain this unit that’s oozing with expensive talent.

Last year, Denver tied with the Osweiler-quarterbacked Houston Texans for last place in the league in plays that went for 20 or more yards. Some analysts believe the offense will again fail to be consistent with Siemian and Osweiler at the helm, but the team is now equipped with a nastier offensive line, so perhaps there’ll be more options down the field. If Bolles can work out the kinks in his game and not keep picking up penalties, he will be in prime position to remain a starting left tackle.

No defense has ever taken the number one spot more than three years in a row, and the Broncos have already slipped behind the Seattle Seahawks. They must remain in the top four – and the offense must improve even a little – for the Broncos to see the playoffs again.

Yvonne Hew is the Denver Broncos Lead Writer for Pro Football Spot. You can follow her on Twitter at @yvonnehew1. Looking for more Broncos news and features? Follow @spot_broncos and @pfspot.