With every great running back, there’s usually a change-of-pace back behind him who is effective.
We saw that two weeks ago when the Minnesota Vikings matched up with the Seattle Seahawks and Chris Carson and Rashaad Penny took turns blasting up against Vikings defenders. In Green Bay Aaron Jones has Jonathan Williams, former Viking Latavius Murray is giving the Saints a different look when Alvin Kamara isn’t in the game and Gus Edwards takes the load off Mark Ingram when the Ravens’ starter needs a rest. And Dalvin Cook has rookie Alexander Mattison.
These No. 2 backs are often successful in terms of yards per carry. Of the seven running backs who average more than 5.0 yards per carry (min. 65 carries) this year, six are backups. In fact, of the aforementioned group, all the backups are picking up more yards per rush than the starter, including Mattison.
Does that mean teams are handing the ball to the wrong guy? Of course not. But it would appear we have an analytics-based explanation.
The website Arrowhead Analytics dove into the idea of running backs wearing down defenses and found that both offenses and defenses lose velocity as a game goes along due to fatigue.
Fatigue* followup: After normalizing acceleration by personnel group & excluding plays where the offense's goal isn't yards (per @SabinAnalytics, @benbbaldwin, & @StatsbyLopez) we're left w/:
More runs may marginally fatigue all players, but has no measurable effect on yds gained pic.twitter.com/JoVwNBJDkE
— ArrowheadAnalytics (@ChiefsAnalytics) December 4, 2019
Backup running backs are one of the few positions in which a player would only see a handful of snaps and be largely at full rest.
The impact of Cook wearing down defenses who then struggle to tackle Mattison has stood out in the fourth quarter for the Vikings. Only six RBs average more yards per handoff in the fourth quarter (min. 20 carries) than the 2019 third-round pick despite the fact that Mattison has faced the fifth most eight-man boxes in the NFL, per NFL NextGen Stats.
The Vikings’ backfield combo has combined for 40 rushes of 10 yards or more. Here’s how some of the other duo’s compare:
Mostert-Breida: 36 (Tevin Coleman also has 11)
Overall the Vikings rank fifth in rushing first downs — with three of the teams ahead of them using running quarterbacks — and eighth in Expected Points Added on the ground, per Pro-Football Reference. That’s a huge gain from last year, in which they ranked 29th in EPA.
Mattison has also tacked on 10 receptions at 8.2 yards per attempt, bumping the total for Kirk Cousins when targeting his running backs to 60 completions on 70 attempts for 585 yards (8.3 yards per attempt).
The takeaway: The story of the year for the Vikings is that they have become one of the best offenses in the NFL and that starts with an offensive scheme that begins with opponents fearing explosive plays out of the backfield. And as games have worn on, the Vikings have taken advantage of the fact that they have a strong No. 2 back who is among league leaders in yards after contact. The change-of-pace in the Vikings’ case is trucking opponents after they have been run down over the first three quarters — and that is proving to be an effective strategy.