Comparing the LA Chargers and 2017 Buffalo Bills defense:
When you just look at the most basic statistics, the Buffalo Bills did not appear to have a great defense in 2017. The team ranked 18th in the league in points allowed per game and 26th in yards per game; two rankings that indicate a defense that is below-average.
However, it is important to note that the numbers are skewed a bit by a terrible three-game stretch that inflated the numbers. In the three games from Week 9 to Week 11, the Bills allowed a combined 135 points. If you remove those three games, the points per game allowed drops to 17.2, which would have been the fourth-best in the league.
This Bills team had some solid pieces on the defensive side of things and were really good (for the most part) in stopping the pass, however, their biggest weakness was stopping the run.
The Chargers defense, to me, is a better version of the Bills defense from 2017. As long as the team stays mostly healthy, then the Bolts will represent a better version of the defense we saw from Buffalo in 2017.
Like the Bills, the biggest question around this team is if they can be better in stopping the run. That is the reason why the Chargers drafted Kenneth Murray and if they can properly limit the run then the team is going to have a top-three defense in the league.
However, if the run plagues the team like years past, then this defense suddenly becomes easier to attack, although it will still be solid.