After snapping their seven-season playoff drought, the Bears are now aiming for a loftier goal: ending their 33-season championship drought. 

Riding the league's top defense to the NFC North crown last season, the Bears finally woke from a lengthy slumber to emerge as a playoff-caliber team with one of the most talented rosters in football. The Bears will now enter the upcoming season as Super Bowl contenders. But in order for them to take the next step and join the 1985-86 team in franchise lore, they'll need their most important player to make the leap from inconsistent to consistent, from OK to actually good, from young and promising to a legitimate franchise quarterback.

Mitchell Trubisky's development in his third season is the key to the Bears' fate. He'll be what determines if the upcoming season is known as the Bears' 2019 season or the Bears' 2019-20 season. He'll either be what holds the Bears back or the catalyst of their ascent. 

That probably seems obvious. Of course, the Bears' quarterback is their most important player. Every quarterback is their team's most important player. That's just the way football works. It's remarkably rare for a team to win a Super Bowl with a bad quarterback. And when a team does happen to overcome a bad quarterback to win a Super Bowl, it usually coincides with that bad quarterback getting hot at the right moment (Joe Flacco with the Ravens in 2012-13) or it requires a historically dominant defense (the Broncos in 2015-16 when Peyton Manning was a corpse). 

The Bears are, therefore, one of the few teams that might be able to make a Super Bowl without great quarterback play. As previously mentioned, their defense was the league's best this past season. If not for a missed field goal, the Bears would've advanced to the divisional round of the playoffs. Who knows how deep they could've journeyed into January if they had a reliable kicker?

But the Bears can't expect their defense to match its production from a season ago. They're likely to see a slight dip in defensive performance, which means they'll need Trubisky to offset that decline with his own ascent. The Bears' defense covered for Trubisky last year. They'll now need him to return the favor during the upcoming season -- albeit to a far lesser extent.

Expect defensive regression

The Bears can expect to regress on defense for a few reasons. First, they lost three key contributors this offseason and were forced to replace them with downgrades. That's just the way it goes for good teams. All good teams get gutted by less good teams in the offseason. The Bears used to be one of those less good teams doing the gutting. Now, they've been gutted by the likes of the Packers and Broncos.

The Packers, who are chasing the Bears in the NFC North for the first time since the Jay Cutler era, stole safety Adrian Amos. The Broncos didn't just steal slot corner Bryce Callahan. They also poached defensive coordinator Vic Fangio by making him their new head coach. Those are three significant losses.

The Bears replaced those players with safety Ha Ha Clinton-Dix, cornerback Buster Skrine, and defensive coordinator Chuck Pagano. Clinton-Dix was a nice buy-low signing with 14 interceptions in five seasons, but there's a reason why the Packers sent their former first-round pick to the Redskins before last season's trade deadline. He's a flawed player. The same can be said for Skrine, who allowed allowed a 124.2 passer rating in coverage with the Jets last year, according to Pro Football Focus. Callahan allowed a 78.9 passer rating in coverage last year. As for Pagano, the former coach of the Colts, he experienced success as the defensive coordinator of the Ravens in 2011, but he's unlikely to be able to fully replace Fangio, a defensive mastermind who has led successful defenses for the better part of the past decade with the Bears and 49ers.

So, the Bears got worse from a talent and coaching perspective. That's the first reason why they might regress defensively. 

The second reason is injury luck. Last season, the Bears had the fourth-healthiest defense in football, according to Football Outsiders. That will likely change in 2019 -- again, don't blame the Bears. It's just the way injury luck usually works.

None of this is intended to serve as prediction of the Bears' defensive demise. But a year after they ranked first in defensive DVOA by a significant margin, they'll likely regress. And that means the Bears will need their offense to improve a year after they ranked 20th in offensive DVOA.

Trubisky's inconsistency problem

The Bears' season is ultimately best remembered by Cody Parkey's double-doink in a playoff loss to the Eagles, but one missed field goal fails to provide an accurate snapshot of the entire Bears season. It's impossible to sum up any entire season with one play, but what that one game did do is serve as the perfect way to succinctly summarize Trubisky's entire season. 

In that game, Trubisky was both dreadful and occasionally brilliant. He finished 26 of 43 for 303 yards, one touchdown, no interceptions, and an 89.6 passer rating.

It could've been worse. In the first half alone, Trubisky was lucky to avoid three interceptions on three poor throws. 

Early in the game, he nearly got pick-sixed on a late throw toward the sideline.

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It nearly happened again midway through the second quarter.

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Late in the first half, on a drive that would culminate in a go-ahead field goal, Trubisky missed what should've been a touchdown by failing to lead his target, who had gained separation from the trailing defender in coverage. It was a great defensive play, but one that was only made possible by an imprecise throw. A better throw would've resulted in a touchdown.

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Later on that series, just before the Bears kicked that field goal, Trubisky got away with his third interception-worthy throw of the half. It looked like he was trying to give the ball away to the other team. It's the kind of what-the-hell throw that happened far too often over the course of the entire season. 

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But much later in the game, when the Bears desperately needed Trubisky to give them a lead in the fourth quarter, he delivered with a 22-yard touchdown pass to Allen Robinson. Notice how he looked off the safety, forcing him to remain in the middle of the field instead of helping over the top of Robinson.

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On the Bears' final offensive series, when the Bears desperately needed a game-winning drive, Trubisky did what was needed. He got them into field-goal range before Parkey kicked away their season. He did so with an incredible throw to Robinson that he squeezed in between two defenders. It was an inch-perfect throw in the most important moment of his career.

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It was the kind of throw that made Trubisky such a tantalizing prospect coming out of college. It's the kind of throw that makes his inconsistencies all the more frustrating. 

His season was filled with incredible passes where the full extent of his potential was reached. But his season was also full of the lowlights similar to the mistakes above.

Over the course of a 14-game regular season, Trubisky completed 66.6 percent of his passes, averaged 7.4 yards per attempt, threw 24 touchdowns and 12 interceptions, and accumulated a 95.4 passer rating. The overall output was decent for a second-year quarterback in a brand new offense. But the consistency on a game-to-game, throw-to-throw basis was lacking.

In six starts, he posted a passer rating below 80.0. In six different starts, he posted a passer rating above 100. He hit awesome highs and dreadful lows.

In games 1-3 against the Packers, Seahawks, and Cardinals, he completed 69.2 percent of his passes, averaged 5.7 yards per attempt, threw two touchdowns and three picks, and posted a 77.8 passer rating. In the next two games against the Buccaneers and Dolphins, he completed 71.9 percent of his passes, averaged 11.8 yards per attempt, threw nine touchdowns and one interception, and generated a passer rating of 143.3.

In game 11 against the Rams, he completed 53.3 percent of his passes, averaged 3.7 yards per attempt, threw one touchdown and three interceptions, and posted a 33.3 passer rating. In the next two games against the Packers and 49ers, he completed 79 percent of his passes, averaged 8.4 yards per attempt, threw three touchdowns and no interceptions, and generated a passer rating of 119.4.

Those numbers showcase his inconsistencies on a game-to-game basis. On a throw-to-throw basis, Trubisky struggles with consistency in terms of his accuracy and decision making.

Much like his near-interceptions against the Eagles, Trubisky too often released passes that had a near-zero percent chance of resulting in a completion -- like the one he tried to squeeze into the 5-foot-8 Taylor Gabriel on the sideline with a defender positioned directly in front of him.

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His accuracy was also erratic. Errant throws that sailed over his target's head were far too common, even if they didn't always lead to an interception. 

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Trubisky's inconsistencies led to a lackluster spot in the leaderboard for Football Outsiders' advanced metrics that measure quarterback value. By DYAR, which measures "the value of the quarterback's performance compared to replacement level, adjusted for situation and opponent and then translated into yardage," Trubisky placed 18th, one spot behind Joe Flacco and one spot ahead of Andy Dalton. By DVOA, which measures "value, per play, over an average quarterback in the same game situations," Trubisky placed 20th, one spot behind Kirk Cousins and one spot ahead of Matthew Stafford in an apparent NFC North quarterback party.

Those numbers tell the story of Trubisky's season. He wasn't awful. But he also wasn't good. 

Reasons to be optimistic 

But it's not difficult to find reasons to be optimistic about Trubisky. There are reasons to believe in his development.

For one, Trubisky was always considered a developmental prospect who needed time and reps before he peaked. He started only one full season at North Carolina. His first NFL season was spent in a John Fox offense. He then had to learn Matt Nagy's system in his first full offseason while playing with a supporting cast of newcomers, from Allen Robinson and Taylor Gabriel to Trey Burton. In other words, it's not a surprise he struggled with consistency last year. 

He should still be developing, which means there's a chance he'll take the next step in Year 3.

"Last year he learned [this offense]; now he's trying to master it," Nagy told reporters at the end of May. "He's done a wonderful job of trying to get to some of the adjustments we have within the plays, concepts and schemes. Hopefully a few months from now, we get to training camp and preseason, and you all see that in game situations."

Second, Trubisky flashed enough potential -- bursts of greatness -- that he should still be regarded as a high-ceiling prospect. When he's on his game, he looks like one of the best quarterbacks in football.

According to NFL Next Gen Stats, Trubisky led the league with six completions with an air distance of at least 50 yards, ranked 10th in average intended air yards (8.8), and finished eighth in aggressiveness (17.7 percent), which measures the percentage of throws a quarterback makes into tight windows. In other words, Trubisky was often throwing the ball deep downfield and toward well covered targets, which partially explains why he struggled with his accuracy.

But it also gave Trubisky a chance to show off his arm -- to make the kind of throws that enticed the Bears enough to make him the first selected quarterback in a draft class that also included Patrick Mahomes and Deshaun Watson (oops).

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Of course, later in that game, Trubisky threw a brutal red-zone interception to cost his team a chance at three points in a game that eventually resulted in an overtime loss, which is the entire problem. It's why we're having this discussion.  

It is worth noting, though, that for all of his faults, Trubisky actually ranked third in QBR behind only Patrick Mahomes and Drew Brees. That matters. Trubisky placed so highly in QBR because QBR factors in running. And Trubisky is a tremendous runner. He rushed for 421 yards and three touchdowns last year, averaging 6.2 yards per attempt. His athleticism is a real weapon. His running ability matters and bodes well moving forward.

Moving forward, it's all about Trubisky continuing to develop as a thrower. It's about consistency. His 2018 season included too many lows that negated his incredible highs. He might be the biggest boom-or-bust quarterback in football. What the Bears need is a consistent quarterback to pair with their great defense -- a defense that should remain great even if it takes a step back next year.

Trubisky has the tools to become that kind of quarterback. He has an innovative offensive coach. He's got a strong supporting cast. We've seen signs of his ascent before. The Bears just need to see him do it on a more consistent basis if they're going to get to the place they're aiming for.

And what they're aiming for is taking the "whole thing."

"Everything -- how short, and how far, we came," Bears safety Eddie Jackson told the Chicago Sun Times when he was asked what will keep him motivated through the summer. "From the losing record to the winning record. How short we came, with the first-round playoff game with the field goal. Right now we just want to build off everything and let that be the fuel to our fire. We plan on taking this whole thing."