During their annual end-of-the-season talks with the local media, both Pittsburgh Steelers team president Art Rooney II and general manager Kevin Colbert made sure to point out how the team’s run defense needs to improve in 2018. None of that was surprising, nor was the fact that Colbert was careful not to put all of the run defense problems last season on inside linebacker Ryan Shazier going down injured in Week 13.

While Colbert was wise not to put all of the blame for the Steelers poor run defense last season on Shazier going down injured, it’s worth noting how bad that unit was against the rush after he suffered the injury to his spine.

Below, I have compiled the run defense stats of the Steelers defense by week and these stats do not include things like quarterback scrambles, kneel-downs, aborted plays and plays wiped out by penalties. These stats also include the amount of successful run plays allowed along with the plays that gained either 10 yards or more and 20 yards or more.

In case you need a refresher course on the criteria I use to determine a successful run, here is quick recap. On first down, a successful run is one that gains 45% or more of the needed yardage. On second down, a successful run needs to gain 60% or more of the needed yardage. On third and fourth downs, however, 100% of the needed yardage must be gained in order for that play to be deemed a successful one.

As you can see below, the Steelers run defense got off to a shaky start at the beginning of the 2017 season. While the Steelers defensive unit did post respectable run success rate of 38.5% in their first five regular season games of 2017, they allowed 5.12 yards per rush, 19 runs of 10 yards or more and 6 runs of 20 yards or more.

After that shaky start to the 2017 season, the Steelers run defense did show signs of improvement in their next five games. During that 5-0 run the Steelers defense allowed just 2.75 yards per carry and a successful run rate of 33.3%, both of which are fantastic numbers. At that point there was hope that that unit had solved their run game woes.

Shazier, as most of you remember, was injured early in the Steelers Week 13 game. From that point forward, the Steelers run defense fell apart. Including that game against the Bengals and through their playoff loss to the Jacksonville Jaguars, the Steelers run defense allowed 4.89 yards per carry and a horrible successful run rate of 50.4%. While the defense only gave up two runs of 20 yards or more in those 6 games, they did allow 16 runs of 10 yards or more. Shazier not being on the field for those six games was certainly noticeably in more ways than one and especially against the run and certainly in the playoff loss to the Jaguars.

In case you’re curious as to what the league average was last season when using the same criteria I used this in this study, I have those numbers for you as well. During the regular season, offenses averaged 4.11 yards per rush and had a successful run rate of 39.4%. In only six games last season was the Steelers defense under both of those averages in the same game. The teams they achieved that success against were the Cleveland Browns twice, the Kansas City Chiefs, the Detroit Lions, the Indianapolis Colts and the Tennessee Titans.