For the Falcons to improve at stopping the run, coaches say their defenders need to be more disciplined in their assignments—except when they don’t.

On every running play defenders have a responsibility, or “fit,” in how they take on blockers and the ball carrier. But defensive coordinator Mike Nolan said he doesn’t want his players being so concerned with their assignments that they aren’t instinctive.

“In run fits, you play as a unit,” Nolan said. “It doesn’t mean you play mechanical at all. That’s what I stress to our guys. We don’t want robots out there because that’s not a good football player. But you can’t try to make a play and go way out of the realm of what you are trying to do.”

The Falcons are trying to shore up their run defense in advance of playing the Giants on Sunday. The Falcons rank 22nd in rushing yards allowed per play and 28th in yards allowed per game. Their nine rushing touchdowns allowed are most in the league, four more than the three teams tied for second.

Nolan and head coach Mike Smith blamed poor run fits for Minnesota’s three “explosive” runs (12 yards or longer) in the 41-28 defeat on Sunday. The Vikings gained 81 of their 244 rushing yards on those three plays, including Jerrick McKinnon’s 55-yard run.

The Saints had four explosive runs in the opener, the Bengals had two in Week 2 and Tampa Bay’s only explosive run was a 19-yard scramble by quarterback Mike Glennon.

Explosive runs were a persistent problem for the Falcons’ defense in 2013. Coaches blamed poor run fits then and it’s still a problem now, with Smith saying linemen, linebackers and defensive backs all sharing responsibility.

“It is very frustrating,” Nolan said. “The one game we did real well (against the Buccaneers) and also in the preseason we did pretty good. I think in a nutshell we’ve got to be more disciplined and play aggressive and play like we did in that game two weeks ago. That’s really it. There’s really no magic.”

It sounds like a tall task for defenders to be both disciplined and instinctive against the run. Nolan said they also have to shed blockers, but that if a defender pushes his man into a teammate’s gap then it’s critical to make a play on the ball carrier or it can result in a big play.

“It’s difficult, but not impossible.” Falcons linebacker Jonathan Massaquoi said. “That’s what they pay us for.”

Falcons linebacker Paul Worrilow, the team leader in tackles with 48, said striking a balance between being assignment-sure and instinctive requires adjusting as a play develops.

“It’s not black and white,” Worrilow said. “You have a responsibility but you have to have the flexibility. This is your assignment, but that ball carrier is trying to find daylight. If there’s a hole and you can be the first one there, you’ve got to go get that.”