How strong is the relationship between offensive line play and team strength?
In recent years, the Seattle Seahawks have had a notoriously poor offensive line. In the past 5 years, Pro Football Focus (PFF) has ranked their line as 20, 27, 19, 30, and 32 out of the 32 teams in the league. At the same time, the team finished #1 in Football Outsiders’ DVOA metric in 4 of those 5 years, and #9 in the other year. On the other hand, there are the Cleveland Browns, whose line has been a consistent strength of the team.…