If you want to trace the moment when the New England Patriots slowly began to extend their outstretched middle finger to the remainder of the football world, you could do worse than flashing back to the 2001-02 season. That year, the Patriots defeated the Raiders thanks to an instant-replay review that was both entirely correct and completely fucked up; that year, Bill Belichick won his first Super Bowl, over the St. Louis Rams, and graduated from a mumbly pariah into a stoic (and oft-reviled) genius.

I bring this up, of course, because Belichick will coach in his eighth Super Bowl this Sunday against the Philadelphia Eagles. He is one of the most venerated minds in football history and he will be coaching in the one of most-watched events in the world.

And once again, he will almost certainly do so while looking like an utter schlub.

Wearing whatever the hell he wanted on the sideline, others told me, elevated Belichick into a radical nonconformist in a sport that has long demanded conformity.

I spoke to several members of that 2001-02 Patriots team for a story about the anniversary of the Tuck Rule game against the Raiders that propelled them into a dynasty. And several of them expressed the sentiment that this was the year Belichick found his coaching voice, the balance between becoming a player’s coach and a cutthroat leader who refused to tolerate dissent within his ranks. And, not coincidentally, one of them also told me that this was also the time when Belichick began purposefully dressing down and wearing those horrific hooded sweatshirts with the sleeves cut off.

Upon closer review, these two things didn’t coincide precisely—Belichick didn’t don his gray hoodie until 2003—but there is a reason they happened right around the same time. They had a symbiotic effect. Winning a Super Bowl, some observers, elevated Belichick into the ranks of elite coaches: “Now, all of sudden, he’s validated everything he’s taught and preached to the football team,” CBS broadcaster Phil Simms said.

And wearing whatever the hell he wanted on the sideline, others told me, elevated Belichick into a radical nonconformist in a sport that has long demanded conformity: “The whole sweatshirt thing caught on back then with Bill,” Patriots punter Ken Walter told me.

And, as science has shown, that refusal to dress up—the whole “sweatshirt thing”—likely only burnished Belichick’s credentials as an unpredictable genius. And it’s why, more than a decade later, the best coach in modern professional football is still the worst-dressed.

A few years back, Silvia Belezza, a doctoral candidate at Harvard Business School, embarked on an experiment with a couple of professors. As part of their research, Belezza went to Milan and asked clerks at luxury boutiques to imagine two types of customers walked through their door, one wearing a fur coat and one wearing gym clothes. (Another hypothetical asked them to imagine a woman in a Swatch and flip-flops, and another in high heels and a Rolex.)

Those clerks were then asked which of these women is wealthier and more important.

The answer that came back was both surprising and not surprising at all. The ones who dressed down dominated the survey. The perception was that the wealthiest people sometimes dress down in order to “demonstrate superiority,” according to one clerk. Another said that the likelihood of someone buying something actually went up when they came in dressed more casually.

So it went with every iteration of Belezza and her colleagues’ research. When they asked students at universities to picture a clean-shaven, tie-wearing professor at a top-tier school and contrast that image with one of a professor with a beard and a T-shirt, the latter was more highly regarded, in large part because he seemed to be purposefully flouting the norms of his profession.

Belezza’s paper was published in 2014 under the headline “The Red Sneakers Effect,” after one of her colleagues taught a Harvard Business School class wearing a pair of red Converse. “People confer higher status and competence to non-conforming rather than conforming individuals,” Belezza, now a Columbia Business School professor, tells me, “because they believe nonconforming individuals have greater autonomy to act according to their own volition and bear the cost of nonconforming to rules.”

I asked Belezza, then, whether Belichick might be an example of what she and her colleagues were talking about. She admitted up front that she knew very little about football, but when I gave her a few details about Belichick’s unwillingness to conform to the NFL’s overarching proscriptions, she had very little doubt.

“This story and his behavior fit precisely our hypothesis,” Belezza says. “Because he’s established as a competent person in his field, he has the latitude to behave as he wishes.”

In 2000, the same year Belichick spurned the New York Jets to become head coach of the Patriots, the NFL signed an exclusive licensing deal with Reebok. Part of the deal called for NFL coaches to wear Reebook merchandise; Belichick, according to Yahoo sports columnist Dan Wetzel, essentially thought the idea of grown men being told what to wear was utter bullshit. Those first couple of years, Belichick mostly wore bland windbreakers on the sideline. But when Reebok issued the NFL Equipment Hooded Sweatshirt in 2003, Belichick clung to the least fashion-forward thing he could find. It was slate-gray and entirely without shape; it was a thumb in the eye of the long-tradition of nattily dressed coaches stalking sidelines.

If you go back through the catalogue of Google imagery, you can see how Belichick’s wardrobe devolved: Photos of him as the Cleveland Browns’ coach show him wearing short-sleeved polo shirts in warm weather; even the admittedly garish orange Browns sweatshirt he wore at times was adorned with a pair of khaki pants that kinda sorta seemed to fit. He was no Tom Landry, but as NFL coaching attire devolved in the ’80s and ’90s from formal attire to casual loungewear, Belichick at least appeared to be making an effort.

At least, until making an effort became a league mandate.

During the 2005 Super Bowl, Belichick found himself constantly pushing up the sleeves of his sweatshirt. Claiming he had “short arms,” he wound up cutting off the sleeves of that sweatshirt during the 2005 season, thereby creating the ugliest garment ever worn by the coach of a professional athletic franchise. Pair that with a set of warmup pants, and you’ve got one of the most brilliant football minds of his generation embracing hobo chic.

Belichick can claim all he wants that he did this for the sake of comfort, but the truth is, he knows exactly what he’s doing. Asked about his attire by Wetzel in 2012, he said he liked “carrying stuff in [his] pouch.” Asked about the sleeves, he repeated that he had short arms.

“Mostly Belichick is defiantly his own man,” Wetzel wrote. “He blazes his own trail and isn’t one to go along with something for the sake of going along with something.”

Belichick created the ugliest garment ever worn by the coach of a professional athletic franchise. Pair that with a set of warmup pants, and you’ve got one of the most brilliant football minds of his generation embracing hobo chic.

Which reinforces pretty much exactly what Belezza and her colleagues were seeking to prove—that Belichick is smart enough to be aware of how he is perceived, and has no desire to ever be seen as ordinary.

It is worth noting that Belichick began wearing his hoodie roughly a year before the emergence of Facebook, which vaulted America’s other most prominent hoodie wearer into the Zeitgeist. Mark Zuckerberg’s sweatshirt has since become the de facto Silicon Valley look for geniuses who want to seem either too smart or too busy or simply too weird to dress up for business meetings.

It may feel casual, Belezza tells me, but it’s all part of the plan, a “need for uniqueness” that motivates people to pursue a different look to distinguish themselves from the crowd.

“High-status individuals may choose to dress informally in business settings,” Belezza says. “Certain CEOs of major corporations, including Bill Gates and Mark Zuckerberg, have been known to appear without ties or even wearing sweatshirts at interviews and formal gatherings such as the World Economic Forum. Some successful entrepreneurs have a habit of attending their companies’ board meetings in casual dress, such as jeans or sneakers.”

So it will no doubt go with Belichick on Sunday. And perhaps, like many Americans, you hate this man, and perhaps you think his nonconformity may have also given him a license to bend the rules. But given that the Super Bowl has long been a cornucopia of American excess, replete with overpriced commercials and overproduced halftime shows, there’s something kind of endearing about Belichick’s refusal to conform to its largely vapid ideals. (Particularly at a moment when the country feels more vapid than it ever has.)

What makes Belichick so brilliant is that he’s never going to do what you expect him to do. He is utterly unpredictable on every level, including sartorially. But if history is any guide, prepare to watch him win again—and do so with cut-off sleeves.