However the Buffalo Bills want to quantify it, defensive tackle Ed Oliver wasn't the same player in 2020 as he was as a rookie in 2019.
Maybe COVID-19 was to blame. After all, the pandemic prompted linemate Star Lotulelei to opt out, creating a hole in the interior the Bills scrambled to fill all season, allowing opponents to pay more attention to the 2019 first-round draft pick.
Oliver was even moved into Lotulelei's 1-technique role after Harrison Phillips, who still wasn't 100% after tearing an ACL the year before, struggled there. So he drew more double teams than he faced when playing next to Lotulelei the year before.
Or maybe it's simply because progress isn't always linear, and sometimes you have to take a step back before taking two or three steps forward.
Whatever the case, Oliver's defensive snap count was almost identical in 2021 to what he had in 2020, but his tackles, sacks and pressures dwindled in a season when the Bills were mostly winning big, forcing opponents to play more one-dimensional than the year before, at least theoretically making it easier on the defense.
How Oliver plays in 2021 will help the Bills decide whether to pick up his fifth-year option, which they will have to make a decision on next offseason, or to give him a contract extension that could lessen his salary cap charge over the following two seasons, pushing the big payments to 2024 and beyond.
The hope is that with Lotulelei returning to clog the middle, Oliver will have a breakout season while returning to the spot he played as a rookie and being able to continue developing there with no more interruptions.
Another factor working in Oliver and the Bills' favor is continuity on the coaching staff. Defensive line coach Eric Washington was new last year and wasn't able to work with the players on the field until training camp, when all kinds of restrictions were in place.
This offseason, in which OTAs and mandatory micamps are allowed again, the expectations are higher than ever.
Oh, and forget about Oliver moving outside. That thought was quickly shot down by defensive coordinator Leslie Frazier during OTAs.
"He's done a good job for us at that [3-technique] position," Frazier said, "and we've drafted some guys that we hope will be able to help us as edge players. But we really like Ed as an interior player and we're looking forward to his maturation over the course of this season this offseason as well. And we're excited about the position we have him at.
"We have some other guys outside that we feel really good about. We're excited about Ed playing in the interior for our defense."
And thriving because of Lotulelei instead of having to cover for him.