I just finished a book I thought was pretty close to perfect. Which simply means Rich Cohen picked a subject that matters to me and wrote exactly the book I wanted to read about it. I didn’t know that book by its cover. When Cohen’s Monsters: The 1985 Chicago Bears and the Wild Heart of Football came in the mail I marveled, Why this book about that team? Enough! It’s over. Long over. But Cohen knows that. As Horatio might have said over the body of Hamlet, “Good-night, sweet prince, but good riddance.”

Cohen mourns those ’85 Bears as much as he celebrates them. He visits them today and sees them as they are. Richard Dent had been “young and lithe, but while I was living my life he got old, became deliberate, heavy footed, slow. The world weighs on him. The youth had been squeezed from him like water from a sponge.”

Jim McMahon: “He was haggard, beat up in the way of a dockworker in his tenth year of early retirement. . . . After shaking my hand, he spit in a cup. His eyes were buggy.”

Emery Moorehead: “He was shaped like a lifeguard, but the lines have blurred. If he walks into the next world like this, they’ll never recognize him.”

Cohen reaches back to the origins of pro football as a brutal sport played by brutal laborers in mill towns. “Football is an angry game, played with punishing violence,” he writes. “People get destroyed on the field, lives end. It makes sense that its first star was someone who’d already lost everything, a ruined man, ill-treated, stripped to his essential qualities: speed, strength, power. Jim Thorpe is the spirit of the game. Every NFL hit still carries the fury of the disgraced Indian, prowling the field, seeking justice.”

After finishing Monsters I saw an NFL lineman on TV send a ball carrier to the turf and dance on the field. I recognized the action’s decadence. He’s counting coup but it’s just for show, I thought; the Indian wars are over. The ’85 Bears were as brutal as a team can be. They won but did not repeat. And then a modicum of civilization began leeching into pro football.

I finally opened Monster on the strength of an earlier book Cohen wrote: Tough Jews: Fathers, Sons, and Gangster Dreams. I hadn’t read it, but I admired the title. I kept reading Monster because Cohen writes one strong, creative sentence after another. The ’85 Bears were his team: He was in high school on the North Shore that year and McMahon was his hero. Cohen and a buddy went down to the Super Bowl in New Orleans and he met McMahon in some joint. McMahon was drunk. Cohen didn’t care then so he doesn’t care now. He doesn’t romanticize, doesn’t judge, and doesn’t regret.

Because the author understands football, he asks the former Bears intelligent questions and they open up to him. His explanation of Buddy Ryan’s fabled 46 defense beats anything I’d read before. The defense was named after safety Doug Plank, number 46, who hadn’t been a Bear since 1982 but played with the reckless malice that was exactly what Ryan wanted from his platoon. The 46 defense was sophisticated in the ways it responded to offensive formations; but its essence was to throw everyone at the quarterback and try to kill him.

Cohen describes the ’85 Chicago-Dallas game, head coach Mike Ditka going against his mentor, the Cowboys’ Tom Landry. “Describing the game is difficult in the way it’s difficult to describe a hurricane: the devastation was everywhere, all at once,” Cohen writes. Dallas quarterback Danny White was knocked out of the game in the second quarter. Ditka would later say about White’s replacement: “I can still see their backup, Gary Hogeboom, when he was already on his way to the turf, and [Mike] Singletary hit him so hard before he could reach the ground that I thought Mike had killed him.” White went back out to start the second half. “I wasn’t going to let them knock me out and just sit over there watching this massacre,” he told Cohen. “It was like watching your kids getting beaten up by somebody and just sitting there.”

White was knocked out of the game a second time when Otis Wilson leveled him, “driving his helmet into White’s spine.” White told Cohen, “I thought I broke my neck.”

Defensive tackle Steve McMichael remembers studying the face of Tony Eason, the Boston Patriots’ quarterback in the Super Bowl, to pick up clues to where the play was going. There were none. “From the start,” said McMichael, “his eyes were wide and empty.” Eason was pulled from the game in the second quarter. He hadn’t completed a pass.

The Bears won that Super Bowl 46-10. But they didn’t win the next year, or ever again. Why not? Cohen examines lots of possible reasons, including Ryan taking a head coaching job and a new defensive coach coming in who played a sissified version of the 46. Then again, part of the problem was the 46 itself. “Simply put,” writes Cohen, “other teams cracked it.” They spread their offenses, which forced the Bears to spread their defense, which made it easier for the quarterback to spot where everyone was lining up, and they assigned more blockers, so there’d be no uncovered defender coming out of hiding to blitz the quarterback. “If you don’t get to the quarterback,” McMahon told Cohen, “the whole thing falls apart.”

“Old gridiron men” speak of football as “already gone,” Cohen writes, as having turned into a kind of “basketball on grass.” And that’s so even though a lot of old gridiron men have sued the NFL for not coming clean with them about the risk they ran of shortened lives and addled brains. Of all the ’85 Bears, “Dave Duerson’s story is the most tragic of all,” Cohen tells us. After retiring, Duerson was a success in business, a leader of the players’ union, “a family man . . . loved by many people.” Then he changed. He became “confused, and sick, and hurt, and angry, and tired.” In February 2011 Duerson died by shooting himself in the chest, after writing instructions that he wanted his brain preserved and studied. He was sure chronic traumatic encephalopathy had been taking his mind away—and he was right.

“I used to hope the Bears would lose the coin toss so the 46 defense would come out first,” Cohen tells us. “I wanted to see the other team not just beaten but annihilated.” (Remember, he was in high school.) Now it seems there’s a new rule modification every year to make the game safer, an unending search for the fix “that can change everything yet preserve what’s important. If we fail, some worry that football will go the way of boxing. Not because people won’t watch, but because parents won’t let their children play. (I don’t know if I’ll let my sons play.) Those who love it know it has to change, as it has changed in the past . . .

“As you follow a team but only love a player,” Cohen concludes, “I find that as much as I love big hits, I love Dave Duerson more.”

Not to mention his sons.

I’d make two small changes in Cohen’s book. Discussing the disease that killed Walter Payton in 1999, he says, “He needed help finding a liver.” Hepatologists tell me this isn’t true; well-wishers all but formed a line to offer Payton a piece of their livers. But from the day he was diagnosed it was too late for a transplant; he already had cancer.

And Cohen stumbles describing the Chicago of his day—the mid-80s—as the “center of the world.” He writes, “The city had shaken off the torpor of the 1970s: Jane Byrne was gone. Harold Washington was going. (He died in office in 1987.) We would soon hand our fate to another Daley. For what are the bad times but a nap between Daleys? It was the start of a renaissance that continues, the rebirth of the greatest city.”

Here’s the only point of any consequence I think Cohen gets wrong. Having grown up in a northern suburb, and then lit out for New York after college in New Orleans, he’s judging Harold Washington from a distance and he wrongly dismisses him. Washington, the city’s first black mayor, was transformational. Racism came to a boil with Council Wars, but afterward Chicago simply didn’t hate the way it used to. (The second Daley got that.) In a study of the golden hour of Chicago’s most violent heroes, the ebbing of civic fear and loathing is something it feels important to get right.