Run defense has become a hot topic in Dallas the last few years, and for good reason. In 2018, the Cowboys enjoyed a banner year stopping the run, buoyed by the strong performance of linebacker duo Leighton Vander Esch and Jaylon Smith. They finished sixth in the NFL in run defense DVOA and surrendered the fourth fewest rushing yards per carry.
The 2019 season saw a big regression in run defense, dropping to 14th in run defense DVOA and allowing the 12th most rushing yards per carry. But the reality is that this was a trend that began at the tail end of the 2018 season against the Colts, which kicked off a five-game span (including the playoffs) in which Dallas allowed an average of 146 rushing yards per game; by contrast, the Cowboys hadn’t surrendered 100 yards on the ground in their five games prior to that Colts game.
While that loss to the Colts was a bit of the beginning of the end for the Cowboys defense under Rod Marinelli and Kris Richard, the next guy to come in and run the defense absolutely blew it to shreds. Mike Nolan, by his own admission, simply tried to do too much with too little time in a contracted offseason. As a result, the defense struggled mightily. Their run defense which finished 23rd in run defense DVOA and allowed the third most rushing yards per carry was especially dismal.