At the time, it seemed like nothing more than the new Falcons offensive coordinator explaining his scheme. It turned out to be a manifesto, one that would be the foundation for one of the better NFL offensive units of all time.

"We believe in the outside zone scheme," Kyle Shanahan declared when introduced as Falcons coordinator in February 2015.

The Falcons would ride those outside zone runs to unprecedented offensive success. Shanahan is long gone, but Falcons coach Dan Quinn believes in the zone, too.

Steve Sarkisian, Shanahan’s successor, used it, but with a much lesser effect. Quinn dismissed Sarkisian after last season and hired Dirk Koetter, who will incorporate zone runs into his offensive design.

It would be great for the Falcons if they can get back to the roots that Shanahan established. But, as the Falcons showed in 2018, none of it will matter if they can’t run the football. And they can’t run, if they don’t have an effective, cohesive offensive line.

That's why I believe it's so important for guard Chris Lindstrom and tackle Kaleb McGary to start as rookies. The Falcons have holdover tackle Ty Sambrailo and new veteran guards James Carpenter and Jamon Brown. But it's better for the Falcons if Sambrailo and one of the guards are insurance, with Lindstrom and McGary part of a new-and-improved line in 2019.

So far so good on getting them up to speed, Quinn said Friday at Falcons rookie minicamp. Lindstrom and McGary already had developed a camaraderie at the scouting combine and Senior Bowl. They were drafted because they are the kind of quick, sudden linemen that tend to fare best in the zone scheme.

Lindstrom especially looks to be a good fit because of his experience at Boston College.

“We ran a lot of the wide zone and (had) the coaching style of coming off the ball and really try to run, and not waddling like a lot of college programs do,” Lindstrom said.

McGary said Washington also ran a lot of outside zone, but he’ll have to adjust his technique.

“My difficulty coming off the ball is having that standard, ‘O-line duck walk, power walk’ drilled into me, where Falcons are very ‘sprint off the ball’ oriented,” McGary said.

Hearing that reminded me of watching Shanahan and his staff work Falcons offensive linemen in the summer of 2015. Those players had to run sideline to sideline more than ever. During games Shanahan called outside zone runs over and over. Once the Falcons mastered them, he ran play-action passes off those runs time after time.

It took time (and the addition of center Alex Mack) but, eventually, the results were fantastic. The 2016 Falcons scored 540 points, tied for seventh-most in NFL history. It was fascinating to watch opponents have no clue how to stop the quick tempo, outside zone runs, and deep passes off play-action.

After Shanahan left to be head coach of the 49ers, the Falcons started to drift away from his manifesto.

In 2017 the Falcons played at a much slower pace with Sarkisian as coordinator. He called fewer play-action passes even though those plays were effective.

In 2018 the Falcons had so many problems along their offensive line (injuries and regression) that they pretty much abandoned outside zone runs altogether. The play-action passes evaporated, especially during the midseason swoon.

Lindstrom and Gary can help with all of that.

“We are both really big, really physical,” McGary said. “We like to come off the ball. And we both know what we’re doing. For the most part.”

Quinn said the Falcons won’t be so heavy on zone runs in 2019. He and his staff studied nearly six years of video on defenses across the league trying to identify trends that the offense can exploit. After that exercise, Quinn concluded: “We will have more mix of our entire package this year.”

I have not looked at six years of video to identify trends, so I will defer to Quinn on that. But I do think Shanahan was on to something when, back in 2015, he said: “When you believe in something that is sound, you drill it over and over and over until you get really good at it.”

Yes, Shanahan played a big part in the Super Bowl collapse, but I still think the Falcons lost something when he left . The outside zone wasn’t just a part of his playbook. It was in his blood: Mike Shanahan, Kyle’s father, had won big using it in Denver. The Shanahans relied on it in Washington, and Kyle Shanahan brought it to the Falcons.

Parts of that philosophical foundation remain, even if they were obscured by the regression of the past two seasons. The Falcons have a chance to rediscover more of it with Lindstrom and McGary in the fold.