THE MAN APPEARING in the doorway of Adam Gase's office late on an October Wednesday night looks like a character out of a nursery rhyme, squat and nearly square. He is an employer of few words, and his presence in this doorway at this moment attests to the overall seriousness of his purpose.

The 2020 New York Jets are winless at this point and will remain so, perhaps in perpetuity, and their record provides only the merest hint of their systemic dysfunction. Gase, the head coach, is sitting at his desk trying to figure out something -- anything, really -- when the visitor arrives. It is nearly 9 p.m., hours after the day's final meetings and a time when every player is usually long gone.

At a tap at the door, Gase looks up to see Frank Gore.

Through 16 seasons in the NFL and 37 years on the planet, Frank Gore is still playing running back. He is the third-leading rusher in league history, an athletic and actuarial marvel who has gained most of his 15,687 yards after contact, a disproportionate number of them on 5-yard runs when the circumstances dictated 2, and all of them after two ACL tears he suffered at the University of Miami. He has been around so long that his son, Frank Jr., is a freshman running back at Southern Miss. His running style, a form of straight-ahead burrowing, is notable for its absolute dependence on utility; it has also led to a career that makes little sense in our current age: remarkable in scope, and criminally underappreciated. He has played the same pitiless game the same way year after year, flinging his body through piles of much larger humans like bait at the end of a line.

Now, hours after his teammates have gone home, he is waiting to be invited into Gase's office.

"Frank, what's up?" Gase asks.

Gore has some questions about blitzes; where they might be coming from and how to stop them. But now he stays rooted in the doorway, looking over his shoulder down the hall. He motions to someone out of Gase's line of sight, impatiently, and says, "Come on, man. Don't be afraid to come in here."

Slowly, head down, looking like a kid following his dad into the principal's office, rookie running back La'Mical Perine appears in the doorway.

"This is the night I look at third-down pressures," Gore tells Gase, "and I brought him in here because I want him to see how I study."

Perine, from Gase's perspective, looks like he might have preferred to stay behind in the film room, content to have the pertinent blitz-related information relayed secondhand. The problem, though, is that Gore sees something in Perine, something somebody else saw in him once upon a time, and the Frank Gore Experience -- whether as mentor or player, whether on a team undefeated or winless -- requires total immersion.

"Frank Gore loves football more than anyone I've ever been around," Gase says. "That kind of thing right there doesn't happen a whole bunch anymore; players would rather go home and play Xbox. It's been rough here, but the younger guys are watching a Hall of Fame running back bust his ass on a Wednesday for a team whose record looks like s--- right now."

OVER THE COURSE of a 40-minute phone call two weeks ago, Gore breaks the news that Antonio Brown has signed with Tampa Bay -- "They're not messing around," he says -- and twice attempts to call Jets strength coach Justus Gatlin to answer a question about how his 37-year-old body feels on Mondays now compared with Mondays from a decade ago. (Gatlin, who didn't answer either time -- "Must be family night," Frank said -- was being summoned to bear witness to Gore's age-defying weekly workout routine.)

"I try not to think about age, and I'm not going to let anybody judge me," Gore says. "At training camp this year, I was making some runs and a couple of young guys were like, 'How old are you, man?' I can tell if I can do it or I can't do it, and I can still do it. You can't get in my head, man."

After 16 years -- in San Francisco and Indianapolis and Miami and Buffalo and now with the Jets -- the enduring image of the Gore epoch will not be a man outrunning defensive backs or making baroque open-field moves. He will be remembered for submitting himself to the game's murkiest tides, seeking the smallest creases in the defense and somehow emerging from the chaos to serve a defensive back a face full of pumping knees. "He's just looking for space, simple as that," says Colts offensive tackle and former teammate Anthony Castonzo. "When I think about his career, my visual is a cloud of bodies and this one guy squirting out the other side."

Gore has made his living running Power through the A-gap, and he has run it so dependably he might as well be holding a lantern. Power is the simplest, most brutal play in football -- sometimes called "God's Play" and the one teams run to assert dominance. A fullback leads, and the backside guard pulls to lead through the A-gap -- the opening to the immediate left or right of the center. It is a play intended to demoralize and erode, and Gore -- ball swaddled tight against his belly with both hands -- has run it as well as if not better than anyone in history. For 16 years he has run this play with a single, consuming goal: find the smallest space between groups of men and run through it. And for 16 years, running Power through the A-gap has been the answer to every question and the solution to every problem. "To Frank," says ex-49ers teammate Joe Staley, "every situation can be made better by running more Power." If the passing game isn't working? Gotta run more Power. If the outside run game isn't working? Gotta run more Power. And if Power isn't working? Gotta run more Power.

"Nobody in the history of the world has ever loved the A-gap more than Frank," Castonzo says. "Absolutely nobody."

The backside offensive tackle has the easiest job on Power. The play happens so quickly there's no reason to do much more than shield the defensive end for a split second and watch what happens. "A dead play," Staley says. "Unless it's Frank." With Frank, the backside tackle has to make sure he works to turn the defensive end upfield, because once Gore gets through the initial pile of bodies, he likes to cut back toward the backside B-gap, like an eel ducking in and out of a reef, and he'd prefer not to be met by an unblocked defensive end.

"Frank always told me, 'Seal that man, because I'm coming back that way,'" Staley says. "He's a savant when it comes to X's and O's and where a play is supposed to hit. He can predict what a linebacker is going to do before the ball is even snapped. All holes are available to Frank."

Gore doesn't just play football, he inhabits it. Even amid the almost-total roster churn inherent to the NFL, his legacy remains in huddles and coaches' offices and locker rooms he hasn't set foot in for years. In his three years with the Colts, Gore became close friends with guard Jack Mewhort, and Castonzo estimates 90% of the interaction between the two consisted of Gore telling Mewhort, "Pull tight. You gotta pull tight." Pull tight -- because it is Gore, and because it concerns the fine grit of the game's inner workings -- has a clear function: If the guard pulls tight, Gore can hit the hole immediately and commence the task of slipping through those small creases.

And so in each of the three seasons since Gore left Indianapolis, whenever a Colts quarterback -- Andrew Luck, Jacoby Brissett, Philip Rivers -- calls "Power" in the huddle, Castonzo and center Ryan Kelly look at each other with a knowing nod, savoring a moment of levity in a grueling game.

"Pull tight," they say in unison. "Gotta pull tight."

As he recounts the enduring phenomenon that is pull tight, Castonzo is driving somewhere in Indianapolis -- the background noise suggests he is driving something large -- and his laugh pierces the whine of big tires on asphalt. "Gotta pull tight," he says twice, and I can practically hear his head shaking as he laughs.

GORE'S PERSONALITY MESHES perfectly with his favorite play: humble, mostly serious, always straight ahead. Jim Harbaugh called Gore "a mystical man" when he coached him in San Francisco, and optimism follows Gore like a bouquet of birthday balloons. It is rare to find a star so universally respected by his teammates and coaches.

"Every time our media guy comes to me and says 'I got a request,' my first reaction is, 'Oh, no no no,'" Castonzo says. "Us O-linemen don't like to talk. But when he says, 'Someone is doing a feature on Frank,' I say, 'Oh, yeah -- I'd love to talk about Frank.' Everybody loves Frank."

Sure enough, Castonzo has plenty of Gore stories -- "I consider it a collection," he says. In one of them, Castonzo -- 6-foot-7 and 307 pounds to Gore's 5-9 and 216 -- describes the first time he engaged with a defensive end, arms chicken-winged to his sides, and felt Gore run under his armpit. "I eventually got used to it," he says. "I don't think he even noticed."

In another, after Gore left the Colts for the Dolphins after the 2017 season, the Colts drafted future All-Pro guard Quenton Nelson with the No. 6 pick of the 2018 draft. Castonzo got a call from Gore shortly after the pick was announced. "So I leave and now they take a guy like that?" asked Gore, no doubt envisioning all the Power he could run with the NFL's best guard leading the way.

"He was kind of giving us flak in a funny way," Castonzo says, "but because it was Frank, he was definitely pissed he didn't get to play with Quenton."

Back in 2009, Gase was a low-level offensive assistant with the 49ers, working with the quarterbacks, when his friendship with Gore prompted him to make an audacious promise: If he ever got a head-coaching job in the NFL, Gore would be on the roster. It has happened twice, first in Miami and now in New York. "He never made anybody feel like he was above them, even though he was a great player," Gase says. "There was always something humbling about the way he was. From equipment guys to trainers to other teammates to coaches, he never disrespected anybody."

Gore thrives on the comfort of routine, abiding by his own rule of law. He pulls his car into the Jets' facility at 6:30 every morning, before every other player. He takes the field 30 minutes before practice, before every other player, to go through a set of elaborate drills Staley calls "like a real practice, not a warm-up." He occasionally ducks his head into offensive line meetings "just to see what y'all are seeing this week."

He takes care of his body in a way best explained by his son: "I look at what he orders when we go to a fancy restaurant," Frank Jr. says, "and I say to him, 'You're going to eat that in this restaurant?'" Harbaugh once said, "Most guys are hungry like they missed breakfast but it's OK because they know lunch is coming. Frank is starving. He plays like he's never going to eat again." And Staley says, "He's a Hall of Fame running back who approaches every day like he was on the cusp of being cut."

Gore sat down with his five children before this season to crowdsource opinions on whether he should keep playing. With Frank Jr. starting his college career, the idea of having Saturdays free held some appeal. "Young guys like to have their parents around," Frank Sr. says, "but if a team wants you ..." His voice trails off. There's no need to elaborate. He goes on to say the decision to return wasn't easy, even though nobody who knows him believes that.

"His self-motivation is ridiculous," Frank Jr. says. "For 37 years old? You wouldn't believe it." His voice rises, and he starts to laugh. He's just getting started. "You should see him do jump cuts, man. You wouldn't believe how many he can do in a small space."

Frank Jr. is the Golden Eagles' leading rusher -- 358 yards, 5 yards a carry -- but he and his teammates are among a handful of football players who can lay claim to a season as dire as the one Frank Sr. is experiencing in New York. Southern Miss is on its third head coach in six games, but its 1-5 record at least gives Frank Jr. something to hang over his 0-8 father. "I tell him that all the time," Frank Jr. says, and he laughs.

Nobody knows when Gore's career will end, not even Gore, but those who know him suggest it will end when the collective wisdom of the 32 NFL teams decides it will end, and not before. "He's going to have to go at some point," says former 49ers tight end Vernon Davis. "Frank is the kind of guy who's going to do what he loves for as long as he can and have fun with it."

It feels a bit like sunset now, with his playing time dwindling and the Jets prepping Perine to be the feature back for the second half of the season. Gore is still productive, still the Jets' leading rusher, but giving regular reps to a 37-year-old running back on a winless team seems like an exercise in nostalgia.

"If he wants to keep playing, and he has the will to do it, why not do it?" Frank Jr. says. "One thing about my dad: no days off -- no days off. That's why I hope he's still there when I get there. I think it's possible because I see what the outside world doesn't see, so nothing would surprise me."

(After Frank Jr. hands the phone back to David Cohen, Southern Mississippi's director of communications, I'm told that Frank Jr. spent our entire phone conversation doing footwork drills -- jump cuts, cone drills without the cones -- in a hallway next to the Southern Miss stadium. "He never stopped moving," Cohen says, "and I don't think he ever does. It's like watching his dad's work ethic in an 18-year-old spirit.")

The idea seems preposterous, but it was thrown around enough over the course of several conversations to merit inclusion: Could Frank Gore be entertaining the idea of sticking around long enough to play in the NFL with his son? No father-son combination has ever coexisted as players in the modern NFL -- no kickers, no multigenerational Colquitts -- and the idea of it happening first with a running back (average career length: 2.66 years) entering his fifth decade seems far-fetched, even for Gore.

"I've heard that talk," Gase says, "but honestly, I can't process it. I can't imagine how that might be possible. It would be awesome, though, wouldn't it?"

Gore's son is rooting for it. The father deflects, saying, "I'm just trying to help these young guys get a win." To that end, he remains a man of structure and optimism, intent on going hard at practice on Wednesdays and staying late afterward. He's dragging a rookie into places he'd rather not go and ordering the healthiest stuff at some of America's best restaurants. He continues on the lonely, quixotic search for the tiniest creases in the defense, and he still thinks the answer to most questions is more Power.

And when all else fails?

Pull tight. Gotta pull tight.

Words to live by.