The Los Angeles Chargers were so close in 2018. Though they finished the season as a wildcard, the Bolts found a new form of electricity in the form of a well-rounded team and a few young studs. Led by Phillip Rivers and Derwin James, the Chargers were able to get their first playoff win in ages, but they eventually fell short of the ultimate goal.
Now, in 2019, the Chargers are back, respected, and more complete than they have been. Coming off of a slow free agency and another good draft, the team is yet again, another Super Bowl contender. But, in order for them to truly take the next step, each of these three X-Factors will have to show.
3. The offensive line

The Chargers' offensive line showed a lot of improvement in 2018, and it's no fluke why. C Maurkice Pouncey proved to be an excellent free agency pickup, while LT Russell Okung appeared to have a bounce-back year. But, far too often, the team dealt with inconsistencies from the pass-blocking unit.
The 2018 line and the 2019 one shouldn't be too much different. Okung, Pouncey, and RG Michael Scofield appeared to be locked into their positions. But, the LG and RT spot isn't quite settled. Last year, Dan Feeney and Sam Tevi played these positions, respectively, but both are playing for their jobs. In replacement of Feeney will likely be 2017 second-round pick, Forrest Lamp, who needs to show improvement in his own right. Rookie Trey Pipkins comes in as competition to Tevi.
To see consistency on offense, the offensive linemen will need to do the same. Although their depth chart isn't set in stone, I will personally call for better offensive line play in Los Angeles until it happens. If not, Phillip Rivers may be running for his life.
2. The rookies and second-year stars on defense

Derwin James was awesome as a rookie, and that's an understatement. In the safety's first season of play, he showed that his versatile skillset could translate to the NFL. He tallied 105 total tackles, 3.5 sacks, 13 pass deflections, three interceptions, and an 87.5 Pro Football Focus grade, good for fifth in the NFL amongst safeties. James' outstanding rookie season earned him a Pro Bowl and a First-Team All-Pro nod — we know he's going to be good next year, making him less of an X-Factor than he is new teammates.
To supplement James, the Chargers went out and drafted Jerry Tillery and Nassir Adderley. Tillery, a defensive interior lineman, will help Joey Bosa and Melvin Ingram speed up that pass-rush and he should start immediately. A better pass rush will help James' defense, but better back end safety play will help James more directly. This is what Adderley brings to the table; he was my highest rated free safety heading into the draft due to his versatility, range, and physical style of play.
A young defensive nucleus consisting of James, Tillery, and Adderley is promising. The three will also help build a stingy pass defense. But, they will also have to show up against the run, as the Chargers run unit has been a significant problem recently.

Philip Rivers' best seasons tend to correlate to the Chargers' win-loss records directly. This isn't anything new, as he proved in 2018. Last year, Rivers looked the part of an MVP candidate as he tallied a 4,308 yards a 32-12 TD-INT ratio on a 68.3% completion rate. His productive season led to a 12-4 record and a playoff win. He'll have to do just the same in 2019.
The Chargers will live and die by Rivers, no matter how promising the defense or run-game is. They've done so since he was inserted as their starter in 2006, and, for the most part, have reaped the benefits. Their reliance on the quarterback makes him an X-Factor by all means. But, at the age of 37, you can bet there will be question marks surrounding him too.