The 1996 Fox Sports promotional video starts with a bunch of scientists straight from central casting, puttering with Erlenmeyer flasks that are bubbling over with smoking fluids. Then, there’s a quick flash of a slap shot accompanied by a laser beam sound effect, one that may have been recorded by a child playing with a Boba Fett figurine. As the puck flies through the air, it’s trailed by a glowing red tail. “On January 20th,” the voiceover announces with great confidence, “you will witness the biggest technological breakthrough in the history of sports.”

The biggest technological breakthrough in the history of sports, it turns out, became one of sports broadcasting’s most-ridiculed experiments. If you’ve watched any hockey game in the past 15 years, you likely noticed that the puck did not radiate any sort of colored light. The technology that was supposed to change the way we watched sports on television lasted just two years. The glow puck has become a punch line, an oft-cited example of lowest-common-denominator TV stupidity. But the biggest problem with Fox’s glowing puck wasn’t the concept. It’s that it was born too soon. Now, 18 years after its ignominious debut, we have the glow puck to thank for the yellow first-down line, baseball pitch tracking, and every other on-screen doodad we’ve come to love.

The glowing puck was Fox’s fault. Soon after acquiring NHL broadcasting rights in 1994, Fox Sports President David Hill began discussions with Stan Honey, then the executive vice president of technology at Fox’s parent company News Corp., about developing a system to track the puck. “[Fox] really wanted to make a splash with the puck,” the glowing puck’s product manager and chief engineer Rick Cavallaro told me, recalling the network’s ostentatious approach to sports broadcasting at the time.

Back in the dark ages of sports CGI, the engineers tasked with making a hockey puck glow, were skeptical. “When I first learned about the project, I wondered, Could it even be done?” Cavallaro wrote in a first-hand account of the puck’s development. Cavallaro says the glow puck, a project undertaken at the behest of Fox Sports, was a first-of-its-kind attempt to track and render a sports projectile in real time. After jettisoning radar and other concepts, Cavallaro and his team at the company Etak—best known for developing early car navigation systems—settled on using infrared technology to track LED lights. Those lights were powered by a battery and a circuit board, then embedded inside a puck that was cut in half and bonded back together using flexible epoxy and other compounds. Those LED pulses—30 times per second—couldn’t be seen by the naked eye, but they were picked up by modified broadcast cameras.

In his history of the glowing puck, Cavallaro wrote that from 10 to 15 pucks with the special discs were used in each NHL game. His numbers may be off here—NHL public relations reports that approximately 35 pucks get slapped around each game. Whatever the exact number, the high volume of pucks made tracking an expensive gambit. On the plus side, the engineers didn’t have to worry about incorporating long-lasting batteries or fret too much about durability.

Even so, the gizmo-filled puck was a technical minefield. When experimenting with transponders, Cavallaro had to be sure not to change the puck’s weight—he says the players could tell if it was off by one-tenth of an ounce. Further, all the different lights in a hockey arena messed with the infrared signal. Early in periods, when a fresh layer of ice reflects everything, even the smallest exit sign could interfere with the puck’s pulse. Beyond that, the broadcast cameras had to synchronize with the puck, whose lights pulsed at regular intervals thanks to an implanted device called a resonator. When the puck was whacked particularly hard, that frequency would change very slightly, just enough to throw off the delicate balance between open camera shutters and pulsing LED lights. The cameras had to be modified by the manufacturer so their shutter frequency could adapt to the puck’s changing pulse.

This was an ambitious, unproven approach, and it failed a critical test one week before “FoxTrax” was supposed to make its luminescent debut at the 1996 NHL All-Star game. In that run-through, the only object Cavallaro could track successfully was the Zamboni. All the bells and whistles at the All-Star game (dry ice, strobe lights, fireworks) made Cavallaro nervous, but in the end, somehow, everything worked as it was supposed to. The puck glowed. When it flew through the air at more than 70 miles per hour, it turned molten red, and it was accompanied by a comet tail. Whoosh!

Hard-core hockey fans reacted to this amazing technological achievement with a mixture of rage and horror. Greg Wyshynski, editor of Yahoo Sports’ Puck Daddy blog, explains it to me this way: “Imagine if you were watching the Super Bowl and every time the running back disappeared in a pile of tacklers he started glowing like a blueberry from Chernobyl.” The red comet tail garnered further hostility—Wyshynski describes it as “NBA Jam for idiots.” In a 2002 reader poll, ESPN.com’s Page 2 named the glowing puck the sixth-worst innovation in sports history, behind the designated hitter, artificial turf, the Bowl Championship Series, performance-enhancing drugs, and, ludicrously, free agency. A 2012 Huffington Post article by Evan Winiker called it “the worst sports broadcasting innovation of our time.”

These attacks on the poor, humble glowing puck are misplaced. Though Wyshynski might not agree, Fox executives were trying to solve a real problem: In the days before HD, a hockey puck was indeed incredibly hard to follow. Tracking a tiny, black, blurry object as it bounced off black skates and black sticks made for frustrating viewing. Hockey watchers had to intuit the puck’s location by carefully scrutinizing the players’ movements, hardly an easy task for new fans. For Fox and the NHL—which was in the midst of relocating teams from hockey-mad Canadian and cold-weather American cities to more populous desert and tropical locales—the glowing puck wasn’t just a goofy promotional tool. It was a needed innovation.

Unsurprisingly, these digital training wheels didn’t sit well with longtime fans. “Right from the start, I viewed the glow puck as a sad commentary on what outsiders thought of both hockey and American hockey fans,” said Wyshynski. “I remember hearing one of the announcers say that Canadians will hate the innovation but American fans will love it.” (This sentiment was indeed expressed by Peter Jennings in an interview during the 1996 All-Star game.) “The inference being that we’re too hockey-stupid to follow the play or that we need to be distracted by shiny new toys in order to watch the sport.”

The shocking truth about the glowing puck is that it was never supposed to glow it all. As Cavallaro wrote:

In our testing, we had just put a blue glow on the puck as an indicator that showed us that we were tracking. It was a diagnostic. And when we demo’d it to the Fox executives we told them that blue glow was just a placeholder. Fox assured us that their art department would develop a final look for the effect, but the one thing they were certain of is that it wouldn’t be the awful blue glow we showed them. In fact, [Fox Sports President] David Hill used to refer to it as that god damn blue hedgehog. Oddly enough, in the end it somehow stayed a blue glow.

No one ever offered a competing vision for how the puck might have popped on screen, but the word Cavallaro kept telling me was “subtler.” Of course, Fox wasn’t going for subtlety. And subtle or not, some people liked the glowing puck: Cavallaro claims that surveys yielded results “pretty close to 50-50.” The shouts of aggrieved diehards, though, drowned out the meek yelps of approval from neophytes.

Fan outrage didn’t kill the glowing puck. After the 1997-98 season, Fox lost its NHL broadcast rights to ABC. Since Fox essentially owned the glow puck technology, the black disc would never light up again.

In 1998, Cavallaro and Stan Honey, formerly of News Corp., launched their own sports technology company called Sportvision. You probably recognize some of Sportvision’s innovations: tracking systems for baseball pitches, a plethora of Olympics doodads, and the whiz-bang imagery that populated the screen during the America’s Cup. During the Super Bowl, Fox will deploy Sportvision’s famed yellow first-down line, as well as player pointers and a snazzy field-goal tracker.

Cavallaro, Sportvision’s chief scientist, says none of this would’ve been possible without the glowing puck, which helped build his reputation in the sports-tech world. “I think most people were impressed by the technology even if they hated the effect,” he says.

Most of today’s Sportvision projects are far different from the glowing puck. The puck—along with today’s NASCAR graphics—used active tracking, in which transponders are physically attached to an object and tracked with cameras. The vast majority of modern sports graphics use passive technology, wherein cameras pick up objects without the need for implanted tracking devices. Even so, Cavallaro says the tricks he learned about electronics and optics while working on the glowing puck have served him well as the sports graphics game has evolved. Wherever you see a yellow first-down line, the FoxTrax puck glows on, however faintly.

The biggest difference between the glowing puck and Sportvision’s subsequent projects isn’t the technology itself but the intent behind it. The first-down line is everything the glowing puck wasn’t: a subtle on-screen cue that helps us understand the game without jamming itself into the foreground. “In terms of any of the [more recent] effects that we’ve done, I’ve never thought about it in terms of the need for it,” Cavallaro says. “I’ve thought about it in terms of what becomes possible and what becomes interesting.” This was the fundamental problem with FoxTrax: It strived to attract viewers to the game rather than improve the viewing experience of those who were already watching. It became a product on its own rather than a broadcast enhancement.

Now that Cavallaro and his team at Sportvision have more experience with broadcast technology, he wouldn’t mind another crack at hockey, tracking not only the puck but all the players, too. “I’d like to make the effect much more subtle,” he assures me. Maybe this involves a much duller glow or no glow at all. Perhaps it would be a slight, black blur behind the puck that can easily be seen against the white ice without adding a foreign color to the viewer’s palette. Whether he gets a chance to improve on the most-hated effect in televised sports, Cavallaro wants the glowing puck to shed its bad reputation, to be looked upon fondly for all that its descendants have achieved in the decades hence. “I’d like it to be remembered,” he says, “as the project that opened the door for all of the things we do today.”