We've spent a lot of time this offseason talking about offenses. Before the draft, we used our weighted system to run through the league's offensive infrastructures, separating them into buckets that included six teams who were not set up for success, nine teams who looked like they would struggle to reach average, 11 teams that should be good but not necessarily elite, and five teams who seemingly could only be held back by injuries. Naturally, the 2020 NFL Draft changed things quite a bit, so we ran those rankings back for an update earlier this week. 

Now, it's time to move to the other side of the ball. Because while offense has a greater effect on overall team performance -- and is more consistent year over year -- than defense, you still need to put up some resistance in order to actually win football games. Rather than go through every team from 32-1 on this side of the ball, however, we're going to reveal our top 10 defenses here, and then debut a list of team from outside that group that have the best chance to crash the party as the best defense in football. 

Without further ado ...

10. Broncos

The Broncos saw two longtime stalwarts leave this offseason in Chris Harris Jr. and Derek Wolfe, but they did a solid job of replacing them by adding Jurrell Casey up front and AJ Bouye on the back end. It's possible this swap provides an upgrade with Casey coming in as arguably the best player of the four. With Von Miller and Bradley Chubb forming the basis of one of the league's better pressure units, plus Bouye, Bryce Callahan, Justin Simmons, and Kareem Jackson patrolling the secondary, and maybe most importantly with Vic Fangio at the controls, the Broncos should remain in the mix for the top 10.

9. Chargers

The Chargers already had an incredible wealth of talent on defense and they added to it this offseason. They stole Harris away from the Broncos, giving them one of the small handful of best secondaries in the NFL. Who are you going to throw at here: Harris, Casey Hayward, Desmond King, or a now-healthy Derwin James? None of these options are fun. Add in the combination of Joey Bosa and Melvin Ingram on the edge, with Linval Joseph, Justin Jones, and Jerry Tillery up the middle, plus Denzel Perryman and now Kenneth Murray cleaning up behind them, and this is a really strong unit. 

8. Rams

The Chargers have a ridiculous amount of depth, but their LA brethren just have a ton of star power. When you have Aaron Donald wrecking defensive lines up front and Jalen Ramsey taking away an entire side of the field by himself, it just dramatically limits what opposing offenses can do. They should be able to account for the loss of players like Cory Littleton in free agency. First-year defensive coordinator Brandon Staley has a lot to work with.

7. Bears

The Bears took a slight step backward on defense last season but still managed to finish the year ranked eighth in defensive DVOA. They still have one of the best defensive fronts in the NFL, and it's been made even more dangerous in the short term with the addition of Robert Quinn in free agency. That may not have been the best value signing over the long haul, but that's not what we're worried about here. There are stars at all three levels with Akiem Hicks, Khalil Mack, Roquan Smith, and Eddie Jackson, and the secondary should be improved after the addition of Jaylon Johnson in the draft as well. 

6. Steelers

Let's start here: The Steelers' defense is likely to regress from where it was last season. Forcing as many turnovers as they did -- and turning them into as many scores as they did -- is just not sustainable from year to year. We've seen this over and over throughout NFL history. However, as we saw with Chicago last season, "regression" doesn't mean that you suddenly become a bad defense. It just means you go from historic to really good. That's the baseline expectation for the 2020 Steelers, who return 10 of 11 starters and brought in Chris Wormley to replace Javon Hargrave up front. 

5. Saints

The Saints already had a very good and extremely underrated defense, but the additions they made this offseason should take them up a level. Vonn Bell was a perfectly fine fit for them at safety next to Marcus Williams, but the addition of Malcolm Jenkins makes for a dramatic upgrade. A full season of Janoris Jenkins should mean improvement at the No. 2 corner spot, and allow Chauncey Gardner-Johnson to move back into a hybrid corner/safety type of role. Throw in their heist of hybrid linebacker/edge rusher Zack Baun in the third round of the draft and one of the league's more dangerous defensive fronts just has another key piece to play around with. Using Baun, Cameron Jordan, and Marcus Davenport on the outside, with Sheldon Rankins, David Onyemate, Malcom Brown, and Margus Hunt up the middle should be incredibly tough for opposing offenses to deal with.

4. Bills

The Bills were already going to have one of the league's better defenses in 2020 even despite letting Shaq Lawson walk and seeing Lorenzo Alexander retire. But then they replaced those guys by signing Mario Addison in free agency and drafting A.J. Epenesa, and so they should see little to no drop-off in their production up front. Add in some development from Ed Oliver -- who looked like a monster as a rookie -- and stabilization of the secondary by adding Josh Norman to a Tre'Davious White-led unit that was already quite good, and this team has the recipe to remain an excellent point-prevention unit. 

3. Patriots

OK so the Patriots are definitely going to regress from their performance last season. It's almost not possible to be as good as they were last year. And that was true even before they saw Kyle Van Noy, Jamie Collins, Danny Shelton, Duron Harmon and Elandon Roberts walk out the door. But they still have Bill Belichick. They still have Stephon Gilmore and the McCourty twins and J.C. Jackson and Jonathan Jones. They still have Dont'a Hightower and Ja'Whaun Bentley at linebacker. And they have added several versatile chess pieces up front in the past two drafts that should help replace the guys they lost. Even with regression, we should expect this to be one of the best defenses out there. 

2. 49ers

San Francisco traded away one of its best defenders in DeForest Buckner ... then replaced him with a like-for-like player by landing Javon Kinlaw in the first round of the draft. We shouldn't expect Kinlaw to be a Buckner-level producer right away, but the depth and star power this team has up front should be able to overcome any sort of drop-off they experience at that spot. Robert Saleh's secondary was arguably the most improved unit in the entire league last season, and they're bringing back every key piece from that group of players. The Niners are going to be a problem once again.

1. Ravens

Did you know that the Ravens finished last season fourth in defensive DVOA? Did you know that they snagged Calais Campbell and Derek Wolfe up front, retained Matt Judon with the franchise added, picked up the best coverage linebacker in the draft with Patrick Queen, added even more depth and versatility to the defensive line with Justin Madubuike, and will now have Marcus Peters for a full season? Do you realize how much depth there is in this secondary? Jimmy Smith is the third-best corner on this team. Brandon Carr isn't even going to start. Oh, and they have Earl Thomas patrolling center field. There are no weaknesses here. Expect big things.