Bill Belichick's Sleeveless Sweatshirts: The Key to Patriots Victory?

By 2003, then four seasons into his tenure with the Patriots, Mr. Belichick was already known around the league for his lovably schlubby sideline style (oversized windbreakers and flaccid pleated khakis) but he went full “Derelicte” on that fateful Sunday in November by lopping off his sweatshirt sleeves. It appeared as if he’d hacked them off at the elbow with a dull butter knife, or set a hungry terrier on them. Despite the seeming spontaneity of the raggedly shorn sleeve look, it has lasted for fifteen years now. In that time, Mr. Belichick has also appeared in other crop-sleeve garments: mock-neck sweatshirts, a blue hoodie and, since 2013, a blue windbreaker. With the Super Bowl looming, Mr. Belichick could not be reached for comment, but he once told the local TV program, “StyleBoston” that he likes the chopped sleeves because he “has short arms.”

Not since Vince Lombardi—then head coach of the Green Bay Packers—took to the field in a short-brimmed fedora in the 1960s, has an NFL coach sported such a notable signature look. (Incidentally, en route to the Super Bowl in Minnesota this week, Mr. Belichick was spotted wearing a fedora that belonged to his late father.) Just as Mr. Lombardi’s rigid hat mirrored the conservative clothes of the “Mad Men” era, Mr. Belichick’s sloppy sideline look reflects our current casualness. Sweatshirts are omnipresent: from designer boutiques that peddle triple-digit cashmere versions for Silicon Valley types, to the Patriots pro-shop, where

Nike

offers a branded “Belichick” hoodie. Pats fans wear that one on Sundays, possibly in the spirit of “Bill— I’m just like him!”

“He’s more relatable dressed that way,” said Pedro Pavia Justo, 22, a public relations coordinator in New York City and longtime Patriots fan. “If you’re on the sidelines watching your team, you should be comfortable.” That said, some fans do wish that Mr. Belichick would dress better because he is their leader. “I don’t know if it’s because they’re athletic but there’s a disconnect in what NFL coaches wear,” said Adam Terry, 30, a Patriots enthusiast and technical trainer in Nashville, “If I’m honest, Belichick’s style is terrible.”

Why is it that football coaches dress so poorly when their counterparts in the soccer world consistently make best-dressed lists? Should Mr. Belichick call up Pep Guardiola, Manchester City’s impeccably dressed coach, for a tailoring recommendation? That wouldn’t fly in the NFL, as the league actually mandates that coaches wear licensed team gear on the sidelines. But at the very least, pleaded Mr. Terry, get the man a nicer set of sweats.

Yet, there is a contingent of Patriots fans that follows Mr. Belichick’s sideline outfits like a game on top of the game. Why? Because they believe in the power of the ratty hoodie. Mike Dussault, a Boston-based fan is their unofficial leader. As the man behind the Patriots blog PatsPropaganda.com, he has taken on the Herculean task of tracking each one of Mr. Belichick’s sartorial choices throughout the coach’s fifteen-year career in New England. Mr. Dussault claims his findings show some correlation between what Mr. Belichick wears and whether or not the Patriots win. Originally, the grey hoodie (then made by Reebok, which sponsored the Patriots until 2011 when Nike took over) was Mr. Belichick’s good-luck charm: Of the 42 games he coached wearing the cut-sleeved version, the team won 32; of the 24 for which he wore the full-sleeved version, the Patriots won 22. In other words, he seems to do better when he leaves the sleeves alone.

Recently though, Mr. Belichick has shown a marked preference for his Nike “Hot Jacket,” a short-sleeved windbreaker that the brand introduced in 2013, frequently opting for it over his slashed hoodie. In the jacket, he’s gone 34-10.

Mr. Dussault feels that with a record like that, Mr. Belichick can’t be unaware of the jacket’s good juju. “He is the most well-prepared coach, every detail of his football coaching is nailed down to the absolute minute, and we’re supposed to believe that he rips in there and puts on whatever?” said Mr. Dussault. “I don’t like to speculate, but that doesn’t add up to me.”

If you study the data on Mr. Dussault’s site, it’s clear that Mr. Belichick doesn’t seem to let a loss one week affect his wardrobe choice the next. He wore the blue “Hot Jacket” at the opening game of this season when the Patriots lost to the Kansas City Chiefs, and yet he wore that same jacket the next week in New Orleans, when they bested the Saints. So what does Mr. Dussault think his curmudgeonly captain should wear this Sunday? “All things considered the ‘Hot Jacket’ is probably what he should wear,” said Mr. Dussault, noting that it’s what he wore last year when the Pats beat the Atlanta Falcons to win Super Bowl 51. Interestingly though, the last time the Patriots faced the Eagles in the Super Bowl, back in 2005, Mr. Belichick wore a full-sleeved grey hoodie. The Pats took that game 24 to 21.

Still, Mr. Dussault pointed out that, at last year’s Super Bowl, Mr. Belichick ripped the Patriots logo off the front of his jacket. “You can see the outline of it, you can see him celebrating and there’s stitching in the shape of the Patriot’s logo.” There was some chatter in the Patriots fan universe that Mr. Belichick’s logo jettisoning had something to do with unrest in the clubhouse, but a year later, Mr. Belichick is still there calling the shots, with and without sleeves.

Write to Jacob Gallagher at Jacob.Gallagher@wsj.com