Under coach Matt Nagy, and led by Khalil Mack, the Chicago Bears took massive strides in 2018. The team won the NFC North and went to the playoffs for the first time since 2010. Yet, the season didn't entirely end the way they wanted; infamously, they lost their wild card game thanks to a missed game-winning field goal.

Despite their heartbreaking loss, the Bears are entering 2019 as a viable Super Bowl contender. They lost key figures to their defense — their defensive coordinator left to coach in Denver, and free agents Bryce Callahan and Adrian Amos left for greener pastures elsewhere. Nonetheless, the Bears still have their star-studded defensive core intact and an offense that could take the next step. However, these three X-factors will ultimately decide if the Bears reach the playoffs again in 2019.

3. Chuck Pagano and the new-look defense

Losing Fangio, Callahan, and Amos hurts, there isn't a doubt about that, but the Bears acted quickly and secured competent replacements for each. Former Colts head coach Chuck Pagano will try to pick up where Fangio left off. He will likely run the same 3-4 scheme, but it may be more aggressive. Instead of sticking to Fangio's nickel blitzes, you should see more linebacker/safety blitzes.

Outside of the coaching staff, the Bears added other high-quality replacements. The team will attempt to negate the loss of Amos with the addition of former Pro Bowler HaHa Clinton-Dix. To replace Callahan is Buster Skrine, one of the most well-rounded slot cornerbacks in the league. If the three additions of Pagano, Clinton-Dix, and Skrine pay off, the Bears should benefit from another elite defense.

2. The development of the offense 

The young pairing of Nagy and quarterback Mitchell Trubisky paid off in 2018. Under Nagy's tutelage, Trubisky progressed in nearly every aspect of his game. The Bears' passing offense was efficient and supplemented their dynamic run game. The Bears created a top-10 scoring offense for the first time since 2013. Trubisky threw for 3,233 yards and 24 touchdowns to 12 interceptions on a 66.6% completion rate, which earned him a Pro Bowl nod.

However, despite bringing good offensive football back to Chicago, Trubisky has a ways to go. His inconsistencies lead to some head-scratching throws, and he still needs to increase the speed with which he reads the field. Notably, he has more weapons than ever before. In the 2019 draft, the team added receiver Riley Ridley and running back David Montgomery, two top-ranked prospects at their respective positions. They also picked up UDFA receiver Emmanuel Hall. They also signed efficient third-down back Mike Davis.

The Bears can't rely solely on their defense. In order for them to take the next step, their quarterback will have to evolve. He has all the tools to do so, and a few new weapons to work with. Nagy is a noted “quarterback whisperer.” If I were to bet on him fixing Trubisky's weaknesses, I would say he'd do so.

1. Their kicker 

No, I'm not attempting to beat a dead horse here. The famed double-doink will be forever ingrained in Chicago folklore, and not in a good way. Last year's Bears team was a legitimate Super Bowl contender; they enjoyed an excellent regular season, and despite a strong back half of their schedule, they had real momentum going into the postseason.

However, their Super Bowl dreams were cut short by the leg of Cody Parkey. The sudden halt to the season makes the placekicker their top X-factor. After the playoffs, Parkey was released, but the Bears still haven't found his replacement. Currently, the team has three kickers on the roster: Chris Blewitt (seriously), Elliot Fry, and Eddy Pineiro. Hopefully, one can solve the Bears' kicking woes.