The growth of the Bills in 2020 was directly tied to the growth of Josh Allen. Rarely has a quarterback so raw and so unrefined made such a jump in just one season. Allen didn’t just become a little more accurate as a passer. He became precise, completing nearly 70% of his passes. And he didn’t improve his numbers by dinking and dunking up and down the field. Throws like this were commonplace:

The traits that Allen relied on to survive his first two seasons (escapability, off-schedule plays, ridiculous throws on the run) are nice. But they, alone, don’t lead to consistent quarterback play.

Precision does. Playing from the pocket and allowing the design of the play time to work does. Manipulating defenders with your eyes (like on the above touchdown) and pump fakes does. That’s what we saw out of Allen in 2020.

And by the way, the ability to make those special athletic plays didn’t go away. They just became more of a last resort for Allen. The end result was an MVP-caliber season. The Bills are banking on the 2020 season not being an anomaly for Allen. They enter 2021 with their offense geared towards spreading it out and featuring the passing game.

The offseason addition of Emmanuel Sanders provides Allen with another downfield weapon to go along with an already-versatile group of receivers. Stefon Diggs can win with speed downfield and crisp route-running at the intermediate levels. Cole Beasley has been outstanding out of the slot and is a trusted go-to for Allen on 3rd down. 2nd-year receiver Gabriel Davis is a dangerous downfield threat (4th in the NFL in yards per reception in 2020). Don’t be surprised to see a fair amount of snaps with 4 wide receivers on the field in 2021.

Here’s how the Bills finished on both sides of the ball in 2020:

On defense, Head Coach Sean McDermott and Defensive Coordinator Leslie Frazier have done a great job of making the Bills a versatile defense. They are one of the few teams that has been able to utilize distinct opponent-specific gameplans from week to week.

That versatility along with effective deception define McDermott and Frazier’s defense. They do a great job of disguising coverages and don’t provide lots of pre-snap indicators. That disguise helps lead to turnovers, an area where Buffalo ranked 3rd in the NFL last season:

Difficulty dissecting what the Bills Defense is doing doesn’t just lead to turnovers. It also prevents the offense from getting into the best possible play at the line of scrimmage. And then it spreads the quarterback’s attention post-snap. That keeps the offense from operating at peak efficiency and generating big plays through the air. It should therefore come as no surprise that Buffalo’s defense finished 5th in opponent QB rating and 6th in 20+yard completions allowed.

The Bills take the same approach with their pressure schemes. They were top-10 in the NFL in blitz frequency last season, often with pressure designed to attack or at least threaten inside. McDermott and Frazier like to challenge pass protection schemes from a mental standpoint, often forcing offensive linemen to focus on one area before bringing pass rushers from another.

The problem with the Bills Defense, though, has been their ability to consistently generate pressure. This has largely been due to the inability of their front-4 to win without the aid of a blitz.

Buffalo ranked 15th in sacks and 23rd in pressure percentage in 2020. That was after ranking 12th and 17th respectively in 2019. The same issues that held back the defense a year before were still on display in 2020. And the season came to an end largely because of Buffalo’s inability to disrupt Patrick Mahomes at all in the AFC Championship Game.

Buffalo’s 2020 offseason moves, including the additions of Mario Addison, Vernon Butler, and rookie 2nd-rounder A.J. Epenesa, didn’t pay immediate dividends. Addison finished with just 5 sacks after four consecutive seasons of 9+ in Carolina. Butler failed to get a sack after racking up 6 the year before. Epenesa only got to the quarterback once. No player on the Bills had more than 5 sacks.

The Bills added Efe Obada to their pass rush this offseason in the hopes that the success he found in his final season in Carolina (5.5 sacks) can translate to Buffalo. They also drafted edge rusher Greg Rousseau with the 30th overall pick.

Rousseau has the potential to make a significant impact given his size (6’7″). But he’s still a very raw pass rusher who didn’t have the chance to refine his technique against competition after opting out in 2020. It would not surprise me to see McDermott and Frazier turn him into a stud pass rusher down the road. I just have a hard time thinking they’ll be able to do it immediately, which would prevent Buffalo’s pass rush from improving substantially in 2021.

Maybe Rousseau and Obada can make a significant difference this year. Maybe Addison returns to form or Epenesa takes the next step in his second season. Ultimately, this is the key area the Bills must improve if they want to go further than they did in 2020.