Sid Gillman is the only coach to be inducted into both the college and pro football halls of fame. Almost half of all the Super Bowls ever played were won by coaches who played or coached for him. He was, by all accounts, a good guy and a superb coach. But his greatest epiphany came to him as a movie-theater usher in Minneapolis. He realized that film could be applied to his real passion: football.

The game would never be the same.

Since Gillman opened Pandora’s box, football coaches have logged untold millions of hours staring at flickering 16mm film, videotapes, DVDs, Blu-ray discs, and now processed computer video files. The coaches also watch their own practice video and blurry recruiting footage sent by eager high school coaches, parents, and recruiting services. They’re looking for an edge–something that only the video can see. An opponent’s weakness no one else has exploited or something in a prospect that makes him look more promising, or less so.

In Schembechler Hall, the coaches and players have a saying: “The eye in the sky never lies.” The average Division I coach probably watches forty hours of video a week, every week, for half the year–almost a full-time job in itself.

Michigan’s former offensive coordinator, Cal Magee, once told me, “When I close my eyes, I see little men playing football inside my head. That can’t be good.”

But try telling that to any self-respecting head coach, and he’ll give you a dismissive snarl in return.

On the first Saturday in October last year, U-M crushed Maryland, 42-21. After the game, while the players celebrated with their friends and the coaches went home to their families, Phil Bromley and his assistant, Kevin Undeen, plus seven paid students, four student interns, and a few volunteers started breaking down the video they’d just shot.

Two hundred-plus computer monitors and TV flat screens cover just about every desk and wall in Schembechler Hall. Twenty-five of them are crammed into the video staff’s windowless, twenty-by-twenty-five-foot office, stacked three screens high at each seat. The “film room” also features a Nerf hoop and a couch, but I’ve never seen either of them used unless a visitor goads the video staff into taking a few shots.

The athletic department spends more than $2 million a year on licenses for the XOS video program, which allows users to do just about anything they’d ever want to do with football video, including identify all twenty-two players on every play in practice then filter them so, for example, a defenseman can pull up any third-and-long play he participated in– all in minutes. It’s not cheap, but if that’s what it takes, that’s what they pay. Most weeks the coaches spend more time watching video than everything else combined. Video is the lifeblood of the profession.

Bromley and his staff sift through thousands of hours of Michigan’s practices, Michigan’s games, and Michigan’s opponents’ games, then package them so the coaches, the players, and the recruiters get exactly what they want, when they want it. Every coach, every night, watches that afternoon’s practice, separated by offense, defense, and special teams. They take all this in while wolfing down their dinners in the coaches’ main meeting room, where the blinds have been drawn for years. If they ever painted the window black, these guys would never notice.

Born in Michigan, Bromley moved in grade school to Florida. After starting at center for the University of Florida, he got an interview with Bo Schembechler to become a graduate assistant at Michigan. When Schembechler asked, “What do you think about being a Wolverine?” Bromley replied, “I’m in, Coach! When do you need me?”

Michigan was still using 16mm film, which Bromley had to break down on an old Steenbeck machine. This required mastering a skill called “hot splicing.” If a coach wanted a reel of defensive goal-line stands, for example, Bromley would cut all those out of the printed copy reel then scrape the chemicals off the first frame of the clip and the last frame of the film he was going to add it to, glue the two pieces together, and seal the joints in the heated press. Once he got the hang of it, he could finish a hot splice in less than a minute.

“We would do about 1,200 hot splices every week,” he says. If they did a shoddy job on just one, the film would break.

“I’ll paint the picture for you,” Bromley says. “You’re in the staff room. Lights out. Coaches sitting around the table. You run the 16mm film through the projector.” Everyone was tired and cranky. If just one of their 1,200 hot splices snapped the screen would turned bright white, the film whipped around the reel, and Schembechler would interrupt himself midsentence: “Goddaaaaaaaammmmn it!”

Bromley and the other GAs would jump up to make a new hot splice, while the assistant coaches would sneak off for a fresh cup of coffee or a bathroom break, relieved Schembechler wasn’t yelling at them.

While Schembechler barked, the graduate assistants sitting against the wall all looked at one another in silent reproof: “Who did it?” Whoever it was would get it after the meeting ended.

Mercifully, Michigan fully embraced the cutting-edge VHS technology in 1989. No more hot splicing.

It appeared Bromley had found his niche–but the following year, the NCAA reduced the number of GAs each team could have from five to two.

“I went home to our apartment that day, knowing that my coaching career was over,” he says. “But sometimes fate works out the way it should.”

Michigan could offer Bromley only a volunteer position, and he was now twenty-seven, and his wife, Jill, was working out of Washington, D.C., as a flight attendant. They hoped to have kids, and Bromley having no income was not a good start.

But then Michigan scraped together $24,000 to pay him as its first video director.

“I had excitement back in my life,” he says. “I missed coaching players, but I knew what I was doing was valuable to the program, and I saw the future. There was going to be more of this, not less. I liked the technology. I was part of writing the book, not just reading it. We were pioneers. At Michigan, if you can make a case that you really need it, you’ll probably get it, and the people are the best. That’s why I’ve stayed.”

Bromley’s life improved when Michigan embraced videotape, but his hours didn’t. With a staff consisting of two students, Bromley slept on the office couch three nights a week just to get the edits to the coaches on time.

By 1995 Bromley had a family, he was tired, and he knew he couldn’t keep up that pace and be a decent husband or father.

Once again the athletic department saved the day–and Bromley’s job–by allowing him to purchase a nonlinear editing system, even though it cost $600,000. Bromley’s load lightened a little more when he took on Undeen as a student assistant.

“There’s a bond there,” Bromley told me, “a lot of trust, and that resulted in me giving him a lot of rope early on.”

Undeen liked the work from the start– and it probably didn’t hurt that the Wolverines won Big Ten titles in four of his first seven years, including one by a young quarterback named Tom Brady.

“I figured it happened all the time,” he says, with a wry grin.

Processing the video from the Maryland game took three hours. Then they turned to Michigan’s next opponent, Wisconsin, processing the Badgers’ game that night against Nebraska. It was early Sunday before they finished.

After a noon game like Maryland, the video staff is usually back in the film room by 8 a.m. on Sunday, though it might be as late as ten if Michigan played a night game and their work was in pretty good shape. They gave the coaches the basic game videos for Maryland, then spent the rest of the day further breaking down the Michigan-Maryland and Wisconsin-Nebraska games into smaller components: offense, defense, and special teams, plus situations like third-and-long, two-minute drills, and trick plays.

The videographers don’t ask why the coaches or players want what they want. They just get to work preparing it. Monday through Thursday, Bromley arrives at 6:30 in the morning to serve the early-rising coaches who want to watch tape on this or that, while Undeen comes in about 8 a.m. Bromley and Undeen usually try to go home by 9:30 p.m., but they can work remotely from home if need be.

“We just keep going until it’s done,” Bromley says.

From July to January, Thursdays are the closest thing to an off-day the video staff gets: they work from 6:30 a.m. to 6:30 p.m.–twelve hours of meetings, practice, and loading the equipment truck. They’re back Friday at 8:30 a.m. to prepare for the next home game or the next hotel if the team is traveling. On Saturdays, they arrive by 8 a.m. for all home games, regardless of start times, while the rest of the staff can come in as late as 4 p.m. for a home night game.

Worst-case scenario: The Wolverines play a night game at Minnesota, Iowa, or Nebraska, and don’t get back to Schembechler Hall until 4 a.m. Though the video staff can start work on the plane ride home, the sun will come up before the game video is ready for the coaches. They celebrate by moving onto their usual Sunday tasks.

“We don’t get much sleep those nights,” Bromley says. “Good times.”

Add it all up, and just like almost everyone else in the building, they’re working more than 100 hours a week during the season and fifty or so in the “off-season.”

Bromley is one of the warmest, friendliest folks you’ll ever meet, a gentle bear of a man. Even at moments of high stress and fatigue, including long flights home after a loss, he never snaps. If a staffer is not meeting his standards, however, they’re likely to see another side.

“You have to understand, everyone we bring in, we’re relying on,” he explains. “We don’t have any extra personnel. If you have a job in this room, we need you to come through.”

First, that means trust. If a player gets into a shoving match or throws his helmet in anger, the Internet would love to see the film.

“That’s all within our family,” Bromley says. “We don’t tweet or Facebook or post anywhere. You cross that line, I’m going to fire you immediately. No three strikes.”

After bowl games, the team truck drives all night to arrive at Schembechler Hall early the next day. Instead of waiting for everyone else to show up to unload it, which could take hours, Bromley tells his staff before the trip they will have to unload the entire truck immediately to get their equipment off in time to get their work done.

“We tell them all before we get on the plane,” Bromley says, “‘If you don’t want to unload the truck, don’t take the trip.’ “

After the 2018 bowl, the interns showed up at 8 a.m.–groggy and hungover, perhaps, but ready, willing, and able to get the job done–except one. After they worked three hours to finish the job without him, the missing student “sauntered in,” Bromley recalls, “acting like he’d forgotten the assignment.”

Bromley was in no mood for lies or excuses.

“Get the fuck outta here,” Bromley told him. “That’s number one. Number two, I don’t know if I want to see you again. We might talk later. We might not.”

Bromley left the student’s fate up to his peers. When he took the other interns out for lunch, he asked them if they wanted the guy back. “Most said, ‘Yeah,'” he says. “If not, he’d be gone for good.

“Look, this is Michigan football,” Bromley concludes. “There’s no halfway here. You’re all in, or you’re out.”

Excerpted from John U. Bacon’s new book OVERTIME: Jim Harbaugh and the Michigan Wolverines at the Crossroads of College Football. His book tour is on his website, johnubacon.com