Maybe you are thinking of 2020, when the whole line was hurt and Andy Dalton got stuck QBing behind that backup line?
2022 was one year ago, 2021 was 2 years ago, 2020 was 3 years ago, etc
Year before last.......
2021 Final Ranking was #1
here it is
2021 PFF Final O-Line Rankings
LT
Tyron Smith | 91.9
LG
Connor Williams | 76.4
C
Tyler Biadasz | 64.8
RG
Zack Martin | 94.2
RT
La’el Collins | 84.0
The Cowboys' offensive line was back to its best this regular season. That resurgence was driven by the return of some of its best players who have missed time with injuries or seen their play fall off because of them.
Tyron Smith earned a 91.9 PFF grade this season, a career high and the first time he has been above 90.0 since 2015. He allowed 11 pressures across 460 pass-blocking snaps. Zack Martin was again one of the best linemen in the game, and the unit's weakest link — center Tyler Biadasz — critically improved his performances and was solid overall. Only Tampa Bay’s line posted a better pass-blocking efficiency score than Dallas this season, and they were blocking for far less time on average.
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but like I said, it's PFF so they have some major flaws