Yards before contact per attempt--these would be the yards attributable to the OL and blocking/scheme. While the yards after contact would goto the ball carrier and sum with the before contact to equal total yards.
Some interesting points
Rams are 18th at 1.2 yards before contact.
NFL Avg is 1.39
Seattle is 31st at 0.6 yards before contact
Arizona is 1st at 2.6 yards before contact.
Interesting how the team the most wants to run is worst and the team that most wants to pass is first.