EARTH CITY, Mo. -- While sitting down to watch the film of last week's convincing win against Houston, the St. Louis Rams' offense may not have expected as much action to come in such a short movie or from its diminutive star.
When the reel began rolling, there on the screen was a picture of a 5-foot-8, 216-pound bowling ball grinding many of the pins in its way into dust.
First, rookie running back Zac Stacy ran through Texans linebacker Brian Cushing. Then, he blasted his way through safety Ed Reed. Two of the league's most accomplished defenders were on the wrong end of some Stacy collisions, drawing the whoops and hollers of everyone in the room.
"I think that just gets everyone fired up," quarterback Sam Bradford said. "[It] gives us kind of a spark to go out there this week and do it again this week because it's fun. I think guys feed off that. The guys up front feed off that when they know that Zac's running that hard. And then even the guys out wide, I think they buy into the run game. You can't take that for granted."
Over the past two weeks, Stacy has clearly given the Rams a much-needed spark. Through the first four weeks, the Rams' running game had been nothing short of dreadful, setting a pace to become one of the worst rushing teams in franchise history.
Previous starter Daryl Richardson had been battling a toe injury after winning what was supposed to be an open competition in the summer. Isaiah Pead continued to struggle to get out of his own way and take advantage of potential opportunities. Undrafted rookie Benny Cunningham showed promise but wasn't quite ready.
After a dismal showing against San Francisco in which the Rams rushed 19 times for 18 yards, coach Jeff Fisher vowed changes to the running game.
One was to install Stacy as the starter. The shift in philosophy and personnel that accompanied Stacy are something of a chicken-or-egg, debate but Stacy's style unquestionably fits best with the powered-up rushing attack prevalent against Houston and Jacksonville.
"He's a strong, powerful runner," Fisher said. "He's got good vision and has got that low center of gravity. He's got excellent lower body strength."
All of those traits have been evident in the past two weeks, as Stacy has carried 32 times for 157 yards, an average of a little less than five yards per attempt.
Although Stacy isn't blessed with breakaway, game-changing speed, his lack of height with a stout frame allow him to run with the power between the tackles the Rams hoped would help offset the loss of the physical presence Steven Jackson brought.
Stacy's yards after contact have been a revelation for a team that was getting almost no production in that area before he became the starter. Of Stacy's 161 rushing yards for the season, 80 have come after contact, an average of 2.42 yards after contact per carry.
Through the first four weeks, the Rams were averaging 2.59 yards per carry total, let alone 1.15 per attempt after contact.
"I think that it's one of those deals where it was a perfect situation for him," running backs coach Ben Sirmans said. "When we drafted him after losing Steven we knew we needed a bigger back that had some power to him. Those are the things he's going to bring to the table with the plays and what we've been doing lately. He just seemed to be a perfect fit for what we want to do and what we have been doing the last two weeks."
Of course, the early returns on Stacy might leave one to wonder what took the Rams so long to give him his opportunity. Stacy was a fifth-round pick in April, which placed him only behind Pead in terms of draft status among the running backs.
Fisher had said during the preseason he wanted to give each of the backs a chance, but Stacy's turn never came after he battled a leg injury in training camp.
"We didn't get a chance to really get him the opportunity to showcase what he could do," Sirmans said. "From a discovery standpoint, you can say that probably delayed that process a little bit but again just based on what he did during OTAs and what he did on film in college, you just had a great feel that he could deliver the way he has the last couple of weeks."
Rams defensive tackle Michael Brockers once played against a younger Stacy when Brockers was at LSU and Stacy was still at Vanderbilt in 2010. Stacy had not yet become the Commodores' starter but he had nine carries against the Tigers' stout run defense.
Brockers played plenty of top-tier backs through his short time in Baton Rouge, but Stacy caught his eye even then because of his combination of patience, size and running style.
"He reminds more of a Maurice Jones-Drew, a short, stocky guy with big legs, low center of gravity so you can't really go out there and try to go after his legs because he can lower his pad level too," Brockers said.
At this early stage of his career, it would be unfair and unrealistic to heap expectations on Stacy as the next Jones-Drew or even some sort of long-term answer for the Rams' running game. They would probably like to at least have a complementary piece with explosiveness to offset Stacy's grinding style.
And while Stacy seems to be wise beyond his years, Sirmans said he still has plenty to learn when it comes to pass protection technique and recognition and other details that go with his position.
Stacy will get his toughest test yet this week against Carolina's fourth-ranked run defense, a unit well ahead of the struggling groups he faced in the Texans and Jaguars.
The soft-spoken Stacy is clearly not a fan of talking about his own success and often steers questions about it to the work of all the running backs or the offense as a whole.
"Right now, we just want to stay consistent, stay productive and hopefully the momentum and success we've been having will carry over to next week," Stacy said.
Stacy's hard-charging style has clearly had a trickle down effect. The Rams offense has been more balanced since he's entered the mix and it's also been more successful.
A rushing touchdown has still eluded the Rams but Stacy's success running in the red zone has set up easy touchdown passes, especially to tight ends, for Bradford.,
That Stacy is having success at a spot where none of the others did might catch some off guard but it's clear he's already earned the trust of his teammates and coaches.
"I wouldn't say I'm surprised by it," Sirmans said. "It's kind of what we expected and he's kind of been the sort of guy that we needed right now."