When I look at the Chargers team stats, a couple things stand out. One is that their run defense is not particularly strong, allowing 4.8 yards per carry. (On the other hand one of the two teams ranked worse was Houston, leading me to believe the Pats would be able to run the ball to victory against the Texans; that prediction did not work out well.)
Their defense ranks 25th, allowing 27.3 points per game. Interestingly there is one other stat that correlates to allowing that many points: the Chargers don't force turnovers. LAC ranks 26th in opponent interception percentage (1.60%) and 22nd in takeaways overall (1.1 per game).
The Pats offense ranks 31st in interception percentage (4.11%) and is 23rd in giveaways per game. As cliche as it is to say turnovers are the key to the game, it truly applies in this game - even though in this case it is a weakness versus weakness.
Also worth noting is that both teams are very inefficient on offense, piling up yardage that yield not enough points. The Chargers rank 22nd with 0.347 points per play, and the Pats are 25th (0.331). The Charger defense is deficient in this category due to their inability to create turnovers, ranking 29th (0.445 opponent points per play).
With both teams involved in so many close games, this outcome could be decided by a field goal. Michael Badgley ranks 24th out of 30 kickers with just a 77.3% conversion rate. Badgley is fine up close (6-6 from 20-29 yards), but just 6-13 from the 40 and beyond. By comparison Nick Folk has made 90.5% of his kicks (12th), including 9-12 from outside the 40.
Los Angeles Chargers team page with results, picks, power rankings, odds and stats.
www.teamrankings.com