An hour before dawn on a recent winter morning, the members of the Jonesboro High School basketball squad file into a darkened classroom to watch tape from the previous night’s win over Eagle’s Landing. On paper, at least, the showing was impressive—the kind of come-from-behind, 14-point victory that catapulted Jonesboro, a public school in the outskirts of Atlanta, to back-to-back Georgia state titles in 2014 and 2015.

But the Jonesboro Cardinals’ coach, Dan Maehlman, is having trouble finding much to praise. "Do you know what it means when I say deny? Am I speaking a foreign language?" he asks, gripping his head as if it’s about to crater open. He gestures at the projector screen, where two defenders are failing to intercept a lob pass. Maehlman rewinds and replays the offending sequence. "Let me try this again for you guys: Deny means that your goddamn player does not catch the goddamn basketball."

The players are largely silent. Most have already spent hours watching the tape on their own, on their smartphones, tablets, and home computers, using software called Hudl. At the meeting, Maehlman, too, is using the technology. Created by three buddies from the University of Nebraska business school, Hudl is built around digital video playback: Teams upload game films (captured either on a mobile device running the Hudl app or a digital camera) to Hudl servers, where they are instantly available to anyone with viewing permissions, from training staff to players to scouts and recruiters. Later, coaches can flag sections of the video (that unprompted turnover in the fourth quarter or that particularly balletic second-quarter steal), inserting notes, scribbles, or audio commentary for their players. They can also use those clips to create digital playbooks for the team. Athletes tap the software to study plays, edit and share highlight reels on their customizable Hudl profile pages, and send their coaches clips to analyze.

Or they can review and discuss in person, as Maehlman and the Jonesboro squad are doing today. A 6-foot-6 former forward for West Virginia’s Alderson Broaddus University, the coach bears a close resemblance to an Appalachian peak—broad at the midsection, broader at the shoulders, and unforested at the summit. In Georgia high school basketball circles, he has a reputation as a brilliant strategist (he was coach of the year in 2015) and a kind of anti-cheerleader: Even when his teams are winning by many points, he tends to pace the sidelines with a look that alternates between anguish and fury.

On the morning I sit in on the Cardinals’ game review, Maehlman’s ire is trained on his team’s defense. He slides his hand over the track pad on his laptop, stopping the Hudl video at minute marker 21:23. The Cardinals’ defense is clustered around their own net. "We were doing this all night long," Maehlman says. On the projector, the Cardinals jerk back to life. "We get the rebound, fine, but then we decide, for some reason, that we’re going to dribble. Why?" Fast-forward. Stop. "Now here, we have the rebound again, and we make the outlet pass, but it’s slow. It’s sideways. It’s almost backwards, for God’s sake."

At 8 a.m., with a half hour before the first bell of the school day, the team heads to the gym and straight into an outlet drill. Standing at half-court, Maehlman observes his sophomore center, Jamari Mosley, dribble off the rebound. "Jamari, did you see the same video as me?" he shouts. "Were you listening? The next player that does that and the entire goddamn team is going to be running wind sprints until 8:30 a.m." On the second go-round, Mosley barely lets the ball hit the ground: jumping rebound, looping pass to his teammate, swish. "Okay," Maehlman says, mostly to himself. "Better." He sounds halfway convinced.

If a whiteboard and erasable marker were the primary tools of the trade for previous generations of coaches, Hudl is fast becoming the 21st-century analogue. More than 100,000 sports outfits around the world currently rely on the software, paying annual subscription fees from $99 (for club teams) to as much as $50,000 (for pros)—and more for the additional tools Hudl is starting to roll out. The service has been adopted by NFL teams and NHL squads and all but one of the 30 NBA teams. Some of the world’s most elite international organizations, including FC Barcelona, the New Zealand All Blacks national rugby team, and almost all the English Premier League clubs, have subscriptions. Hudl’s widest adoption, though, has been among college, high school, and club teams in the United States. In the basketball vertical alone, nearly 22,000 schools and colleges count Hudl as a foundational coaching tool.

Despite Hudl’s ubiquity, many observers were taken by surprise when the bootstrapped, Lincoln, Nebraska–based startup announced last spring that it had raised $72.5 million in a single Series B investment round, giving it a $250 million valuation. It was startling news to anyone unaware of the subtle yet transformative effect Hudl has had on the way coaches and players at all levels communicate with one another and the outside world.

"We want to capture and add value to every moment in sports," says CEO David Graff, who founded Hudl in 2006 with fellow computer engineers John Wirtz and Brian Kaiser. At Jonesboro High School, Hudl is integral to almost everything the basketball team does. The morning after nearly every game, Maehlman takes his players through his annotated reel; before big matchups, he screens films of the opposing team. In addition to the video features, the software keeps track of individual and squad stats and automatically creates graphs and colorful shot charts depicting patterns in the team’s play.

Maehlman also uses Hudl when talking to recruiters. Last year, for instance, he directed representatives from a handful of colleges to the Hudl profile pages of two of his top players, Tariq Jenkins, a senior point guard, and James "MJ" Walker Jr., a 6-foot-6 junior shooting guard who’s almost certainly bound for the NBA. The profiles included highlight clips, stats, and even test scores and grade-point averages. "By the time they got done looking at those pages, the recruiters knew everything they needed to know," says Maehlman. "And I didn’t have to spend hours emailing back and forth with them."

Like a lot of successful software, Hudl was conceived as a digital replacement for a task long done by hand—in this case, the exchange of the game tapes that coaches use to keep tabs on the competition. "You’d have people driving hundreds of miles to trade DVDs or waiting days for the things to come through the mail," says Graff. "And once you got the tape, there was so much data and so many plays to break down and no easy way to do it. We set out to change that."

In early 2006, Wirtz, Kaiser, and Graff, a graduate assistant for the Nebraska athletic program, managed to get a beta version of Hudl—then known as Huddle—in front of Bill Callahan, the head coach of the nationally ranked Cornhuskers football squad. The software was pretty bare-bones: a media player, essentially. But Callahan immediately grasped the potential. If the pair could have a finished version of the product ready by the start of the 2007 football season, Callahan said he would use it.

Luckily, Wirtz, Kaiser, and Graff had good timing: Video hardware was becoming more affordable, as was cloud storage. And the smartphone, while not yet ubiquitous, was ascendant. Together with a small team of designers and user-interface experts, Wirtz, Kaiser, and Graff refined their software, building in the crucial ability to capture video via mobile devices and to review that tape on pocket-size screens. When Callahan landed a job as assistant coach of the New York Jets, he took Hudl with him.

The Hudl founders hoped other pro teams would quickly adopt their technology, but that didn’t happen. "We had eight months there where we were kind of beating our heads against the wall," Graff recalls. The breakthrough, as he tells it, was Hudl’s decision to expand into high school sports. After all, the pool of pro teams is small. The high school market is almost limitless. So in 2009, after opening a pilot program at 12 schools in Nebraska, Texas, and Kansas, Hudl dropped the starting price of an annual subscription to $800 for high schools. By 2010, it had signed 2,000 teams. The number grew from there: 7,000, 8,000, 80,000, more. And not just football, but also basketball, soccer, baseball, and volleyball.

Hudl didn’t just make coaching easier­; it changed the way sports organizations operated. "Sports has been undergoing this tech revolution on so many levels, where it’s all about having an objective approach to performance measurement," says Vince Gennaro, director of the sports management program at Columbia University. "We now have wearable technologies, high-speed cameras, Doppler radar, and data-collection devices that will measure everything from the pitch recognition of a batter in baseball to the force of impact on a tackle in football to the spin rate and spin axis of a shot on goal in a soccer match. And we’ve only scratched the surface."

Hudl’s genius was to democratize the tech revolution Gennaro describes by bringing it to pro teams as well as high school, youth, and rec-league teams. Here were shareable, editable, accessible analytics of the kind typically reserved for moneyed pro organizations. "You’d have a conversation with one coach, and next thing you know, you’d get a call from another a county over, someone saying this is what he’s been waiting for," recalls Jason Aldridge, a former football coach and the Hudl sales rep for Georgia and South Carolina. "It was very much filling a void for these teams."

As it grew, Hudl snapped up smaller competitors such as DSV and Apex Sports, expanding its market share. Acquisitions of London-based Replay Analysis and Australia’s Sportstec have helped grow Hudl’s presence among international and elite teams. And with the purchase of startups like Ubersense, a slow-motion-video-analysis company, Hudl has expanded beyond its signature subscription app. The new Hudl Technique, a free stand-alone app based on Ubersense code, lets athletes see the velocity and angles of, say, a golf swing or soccer kick, or the form of a free throw. The software, which has been used by Olympians in 20 disciplines, gives Hudl entrée into non-team sports, such as golf, tennis, snowboarding, and even CrossFit. The Hudl Combine app, the product of a new partnership with Nike, lets players upload stats from the 40-yard dash and other football combine events and share them with potential recruiters.

Officially, the company, which has 400 employees around the globe, does not disclose annual revenue, but estimates are generally in the neighborhood of $30 million, up from $1.4 million in 2010. In the coming months, Hudl will release a pair of new, paid add-ons to its core subscriptions that are currently in beta. The first, Hudl Assist for basketball, takes all data entry off management’s hands—coaches submit video to Hudl, and a professional sports analyst tallies and breaks down all the statistics from the game. Later this year, Hudl will launch Sideline, a live-playback feature. Coaches can connect up to five devices to Sideline, and share and annotate clips in real time. Spot a weakness on your opponent’s defensive line? You can call a time-out, bring up the relevant clip on your iPad, and point out the opening.

"The best way I can describe Hudl to you is that it’s just streamlined a whole lot of processes for us," says Maehlman. "Need tape? It’s there. Need info on an opponent that you might face in the semifinals of a state tournament? Or exactly how one individual player shot from the free-throw line? That’s there too. And it frees me up for what I need to be doing, which is concentrating on coaching and the team."

In mid-December the Jonesboro Cardinals travel by bus to Christian Brothers High School, in East Memphis, Tennessee, for the eighth annual Memphis vs. Atlanta Roundball Classic. The two-day event will not affect the Cardinals’ progression toward the state finals. But the symbolic importance of the tournament is hard to ignore. In the summer after the 2015 championship season, the Cardinals lost several high-producing players, and the cohesion and solidarity of prior team lineups have not yet manifested themselves. Maehlman has been pushing his team hard over the past few weeks with a routine of game reviews and drills. The idea: use Hudl to show players what they need to do; use practice to get them doing it instinctively. It’s exactly what Graff envisions for his software: "Hudl is about enhancing learning opportunities."

Jonesboro is scheduled to play two games during the Roundball Classic. The first contest is a win but a desultory one––the Cardinals left Georgia at 5 a.m., and their fatigue is obvious. The mood for the next night’s game is far livelier: The stands are full, and nearly everyone in the room is rooting for the Cardinals’ opponents, the Devils of nearby Germantown High School.

Although the Cardinals start strong, their defense soon starts to fray and the scrappier Devils take advantage. By halftime, the Cardinals are up by just two, and they struggle throughout the second half until, with four seconds left, they’re down by three.

What happens next is magic. How else to describe it? With three seconds remaining, the Devils miss a layup that would have buried the Cardinals for good. That’s when Mosley, the very player Maehlman had called out for dribbling off the rebound a few days earlier, grabs the ball—two seconds remaining—and chucks an outlet pass to Jenkins. The clock whirs down to one second. Jenkins is at half-court. Pushing off his back right heel, he reels forward and releases his grip on the ball. The buzzer rings. The ball drops through the net.

For a moment, the auditorium goes dead. The Cardinals bench surges forward to wrap Jenkins in a hug. The momentum has shifted. Now it is the Devils who are off balance. Overtime ends with the Cardinals on top by 12 points. It is a banner win, a small miracle set in motion by meticulous coaching. After the game, the Cardinals burst through the double doors of the locker room, hollering and screaming, with Maehlman charging in after them. For the first time all day, he is smiling.

A version of this article appeared in the March 2016 issue of Fast Company magazine.