WHEN CORTRELLE JAVON Anderson begins to run, when he has his short and fat (his words, not mine) body headed toward the line of scrimmage, you'd be forgiven if you were momentarily alarmed by the idea that he intends to disappear. His shoulders hunch, his torso appears to retract, and his Doric thighs look like they're going to sink into the turf. He's listed at 5-foot-8 (maybe) and 225 pounds (please), so he's low to the ground to start, especially compared with everybody around him. With a football in his hands, he practically tunnels. If it ever becomes possible, and legal, to take a subterranean route down the field, bet on him being the first.

There is very little in the way of decoration. Football guys describe runners like C.J. Anderson by saying they know how to use the field. He is wide. He is short. He is strong. He has remarkable balance and great vision and employs just enough subtle deception to leave linebackers tackling air. If he can't fool them, he is perfectly content to go directly through them. It is brutal art.

We don't get surprised much anymore. When we do, the surprises are usually delivered by the people we expect to surprise us. Tom Brady and Drew Brees defying every known actuarial chart is an ongoing, low-grade surprise. Aaron Donald playing defensive tackle like a turbocharged Jeep retains its capacity to surprise. Patrick Mahomes seems to surprise everyone but himself. But this kind of surprise, The Anderson Surprise, in which a man emerges from nowhere in the most ridiculous and delightful way to become a recurring star in a late-season drama, is rare enough to qualify as preposterous.

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His employment record over the past 10 months looks like this: released by the Broncos after five seasons, more than 3,000 yards, a Pro Bowl and two Super Bowls; signed and released by the Panthers after nine games and 24 carries; signed and released by the Raiders after five days, and no games, in Week 15.

"Every team I was with had a circumstance for why they felt like they had to get rid of me," he says. "Every one was understandable, and I understand this is a business first. If you look at the circumstances, it makes perfect sense. It would've been easy for me to get down on myself, but I didn't because it wasn't a talent issue."

He signed with the Rams a week before Christmas, after Todd Gurley dinged a knee and backup Malcolm Brown was lost for the season. Anderson has played three games with the Rams: 167 yards against the Cardinals, 132 against the 49ers, 123 and two touchdowns in the divisional-round victory over the Cowboys. He exudes all the radiance and none of the bitterness of a 27-year-old man who knew he wasn't finished but thought it was completely understandable if nobody else agreed. He knew he could do this, he says, which is an entirely different thing from expecting it to happen.

You could cite mitigating reasons to explain Anderson's emergence: the disposability of running backs, the dominance of the Rams' offensive line, the changeup-fastball routine he has developed with a healthier Gurley, the brilliance of Sean McVay's offensive schemes. All carry a measure of truth, but any attempt to quantify and thereby minimize the joy of watching someone have the time of his life is like dancing with the sound off.

It's much more fun to watch him as he lowers his shoulders and swivels his hips and rolls that body downfield, around, into and under defenders. Anything longer than 10 yards takes on the vibe of a slow-speed chase. In the open field, his quick feet and angle-free body make it difficult to wrestle him to the ground. There's nothing to grab on to. It's like trying to tackle a rolling wine barrel.

"He's always been able to make people miss, no matter what shape he's in," says John Beam, Anderson's coach for two years at Laney Community College in Oakland, California. "Where does that come from? Don't laugh, but maybe from playing years of tag as a kid."

This feels like we're taking the legend one step too far, maybe drifting into apocrypha. Tag? Could tactics learned and employed in the simplest game in the world -- every active American child's introduction to competition and humility and the varying degrees of athletic ability among kindergartners -- translate to the world's most corporate and overanalyzed sport?

Anderson does laugh, because it's true.

"There's a specific move I use that I won't give out," Anderson says. "I'll just say I do something with my shoulders that puts me in open space a little faster. You can look for it. And yes, it came from playing tag. It's my tag move."

Somehow, this story just became more ridiculous. He might have dodged the label all those years on the playground, but he can't avoid it now: C.J. Anderson is It.

"Todd was excited C.J. was here to help carry the load," says Rams assistant Aaron Kromer. "As soon as C.J. got here, Todd could feel the benefit. Late in the game, he's still got fresh legs." Paul Spinelli/AP Photo

ON THE OTHER hand you have: Todd Gurley, the NFL's most regal runner, elegant and composed. He and Anderson are poles apart in style and bearing. Gurley, a first-team All-Pro, runs upright and fast, bursting into the open field like a statesman, like it's owed to him, like he's done it his whole life and sees no reason it would ever be anything different. Tacklers approaching him know they can't take him on high because he'll shed them. Going low means eating a knee or two. He is 6-1 and 224 pounds, a sculptor's ideal.

It is an unlikely pairing on many levels, as if Rams general manager Les Snead is secretly using this season to sell his screenplay for a buddy comedy. But as a purely aesthetic study, watching one brings a greater appreciation for the other.

The plan was for Anderson to show up, learn the offense, take the Rams through the final two games of the regular season and, if that plan worked, play a few downs in the playoffs to save Gurley's legs. He was a short, fat (again, his words) umbrella policy. But along the way he presented McVay with a problem: How do you bench someone who averages 6.4 yards per carry?

The shiny new object gets all the attention, but the Rams go out of their way to hammer home the point: Gurley is the man.

"Todd was excited C.J. was here to help carry the load," says Rams assistant Aaron Kromer, who coordinates the running game. "Playing every down at running back is like playing every down at defensive line. It wears you down over time, and as soon as C.J. got here, Todd could feel the benefit. Late in the game, he's still got fresh legs."

Still, the possibility for tension exists. Gurley could look at his team's 273 rushing yards against Dallas and figure a few more carries for him and a bit fewer for Anderson and he would have topped 200 by himself. After the Cowboys game, Gurley was asked an oddly phrased question that suggested his injury was a blessing in disguise; without it, the thinking went, Anderson would never have worn a Rams uniform. The question managed to combine a lack of compassion with a complete lack of tact. Gurley did his best, praising Anderson and saying, "Maybe it was a good thing I got hurt." He followed those words with an icy smile that wasn't particularly convincing.

Anderson is 27, just three years older than Gurley, but his scraggly old-man beard and mountaintop wisdom make him seem considerably older. He describes Gurley as "a superstar in this league who still works every day like nobody knows his name," which, true or not, is sheer poetry.

"Whatever Todd wants to do, we were going to ride with," Anderson says. "If he wants to play 98 percent of the snaps, we're going to let 'the man' be 'the man.'"

Outwardly, there are no signs of strain. When Anderson ran off the field after scoring his second touchdown against the Cowboys, Gurley met him 10 yards off the sideline with a command: "Two spoons. Two spoons." Dutifully, Anderson mimicked the act of feeding himself with alternating utensils, which might be just be another sign of Anderson's self-deprecation. Or, if we're going for depth and symbolism, two spoons signifies Gurley's willingness to subjugate his ego and offer Anderson a seat at the communal table.

"I always had my eyes forward, even with all I went through this year, and I always bet on myself," Anderson says now, one win from the Super Bowl. Gary A. Vasquez/USA TODAY Sports

THE PADS AND the helmet obscure everything: faces, expressions, motivation, the internal combustion that got every one of these guys here in the first place.

What's it take to get here? Anderson was raised by his mother and grandmother in Vallejo, California, in a locally famous neighborhood (Mac Dre, E-40, CC Sabathia) called The Crest. Or, irony intended, Country Club Crest. He played quarterback for two years at Jesse Bethel High School and, during a game in his sophomore season, his team was backed up to its own 1-yard line. The offensive coordinator called for a quarterback sneak, which might not have been designed for what happened: a 99-yard touchdown run. "I'll always remember that play: 15 Crack," Anderson says. By his senior year, he had switched to running back.

His coach, Jeff Turner, laughs when he is asked to describe Anderson's personality.

"Well, C.J. just loves to talk," he says. "There were times we had to, in our own way, tell C.J., 'Listen for a second. Just listen for a second.'"

A nonqualifier out of high school, Anderson went to Laney in Oakland. He didn't have a car, and the only workouts he could make traveling 33 miles on public transportation were at 6:30 a.m. He remembers the details like they're written on his hand. He woke his grandmother before 4:30 every morning so she could drive him to catch a 4:45 bus that would take him across the Carquinez Strait to the Richmond BART station to catch a 5:15 train to Oakland. He would arrive at the Lake Merritt BART station at 6:05 and walk to Laney for a 6:30 workout.

"That's what it took," he says. "It took sacrifices and a lot of early mornings. It took the help of my grandma. I always had my eyes forward, even with all I went through this year, and I always bet on myself. It's perseverance and bravery. I was bold and brave to continue to keep going."

When the Division I coaches, including Jeff Tedford at Cal, Anderson's ultimate destination, started calling Beam, they'd always ask him, "What's his 40 time?" He would give them an answer because he had to. "I got him at 4.4 on my Casio," he'd say. "But I've got a question for you, 'Do you see anybody chasing him down? You don't, because it means too much to him.'"

So you can sit back and laugh along as he calls himself fat and short and slow. You can watch Andrew Whitworth and Rodger Saffold and John Sullivan road-grade massive holes through the defense and say most ambulatory humans could gain 50 yards playing behind that line. But you can't see the drive, or the people or the places or the buses or the trains. You can't hear that early-morning quiet in Grandma's car.

Anderson will tell you: What you see on the field is often a result of what happens when nobody knows who you are but you.

OK, SO ABOUT the fat:

First off, before you mock or judge, the man thought he was done for the year. On vacation. He was going to get back to the fitness thing eventually, but he figured he had time. It's not as if he was particularly active before this; those 24 carries in Carolina didn't qualify as marathon prep. He had a few weeks off after he left Carolina, and it's not as if he was going to drop pounds over five days in Oakland, especially when he had to learn the offense at the same time.

And so he found himself jobless in Week 15. He'd been cut for the second time in six weeks, playoffs were coming up, the phone wasn't ringing. "I thought, 'OK, that's over,'" he says. "I shut it down."

But Gurley injured a knee and the Rams called. "Off the couch," Anderson says. When he got to Southern California, he had to spend more time in the classroom than on the treadmill. He arrived at the team's Thousand Oaks facility at 5:30 every morning and didn't leave until 8 p.m. He watched film and studied the playbook and asked a ton of questions.

"It's a testament to the maturity of our team to accept him at that point in the season," Saffold says. "And it's a testament to C.J. to be able to come in and understand this offense in four days. And it's not just any offense, it's McVay's offense. There's a lot of words and a lot of different categories, a lot of switches and a lot of long, long names for plays."

Beam watched Anderson run for those 167 yards in his first game with the Rams and told his wife, "Uh-oh, C.J.'s fat again. You can always see it in his cheeks." It's tradition that Beam's wife bakes scones for the Laney players, and there were times during Anderson's two years that her husband pulled her aside and whispered, "Don't give C.J. the sweets."

Amid the postgame commotion in the Rams' locker room Saturday night, quarterback Jared Goff yelled, "Fat Back!" when Anderson began interviews at his locker. There was a quick burst of uncomfortable laughter. Was this OK? Why would Goff insult the man who just spent three hours burrowing his way up and down the field in pursuit of a common goal?

"All good," Anderson says. "I call myself Fat Back. We'll keep that going as long as this season goes. I think it's comedy. We're entertainers. Look, I'm 12 or 13 pounds overweight. I'm not going to lie about that. But I'm not overweight to the point where I can't play the game. As long as I'm still moving and doing the things I need to do, I'm OK being Fat Back, but people don't know the grind. I'm here breaking down tape at the facility on my off day, and I'll be here at 5:30 tomorrow morning breaking down more tape. It's funny when you hear people say, 'He's just off the couch; I could get off the couch and do that, too.' Well, I applaud you. Come on. Come do it."