ESPN's Sunday Night Football broadcast on Sept. 27, 1998 — 15 years ago this week — featured an unremarkable matchup between the Baltimore Ravens and Cincinnati Bengals. But the game bears a historical footnote most NFL fans probably don't know—it also marked the debut on TV screens across the country of the now-ubiquitous yellow line that's digitally imposed on football fields to show where a team needs to reach for a new set of downs.

Earlier that same year, Bill Squadron and Stan Honey left their jobs at News Corp to build a startup. Its name: Sportvision. Its goal: Leveraging technology's rapid growth to improve the sports-viewing experience for fans at home.

The company has since developed a host of game-enhancing products for Major League Baseball, NASCAR, the NBA, the NHL and more. But it was a meeting with ESPN executives in New York City 15 years ago that would springboard Sportvision to instant success. The meeting birthed the yellow first-downline—high-definition and instant replay aside, arguably the most significant technological innovation for sports fans on the couch.

That yellow stripe has since become a staple of the NFL-viewing experience and a symbol of how technology has revolutionized the ease of being a fan. But it didn't just come to be on its own, and how it was born contains factoids and tidbits that will fascinate any NFL fan or media nerd.

Fifteen years after it debuted, we spoke with key players from Sportvision and ESPN, as well as some fans, for the inside story on how that yellow line got to your TV screen and how it has changed since. Read on for the interesting tale behind an oddly endearing bit of sports history.

An Oral History of the Yellow First-Down Line

Bill Squadron (Sportvision co-founder and former CEO, now head of Bloomberg Sports): People had been talking about the idea of an electronic first-down line on telecasts for some time. I think I mentioned in a piece I wrote for SI.com that there had been a patent filed for a different way of doing it many years before. So it was on our list of things we wanted to do when we started Sportvision.

We demoed it for all the NFL rights holders. The reaction of most was positive but cautious. There were concerns about the cost. We got a lot of positive reinforcement but people were cautious.

Jed Drake (ESPN's vice president of production): When we heard Sportvision was keen to work with us, we said, 'Why not, let's give it a go.' So we ended up meeting in ABC's offices in New York. One of the things we've always seen as important at ESPN is seeing technology as a way to absolutely enhance our presentation when it's done right, a way to tighten the experience for viewers and give us some separation between ourselves and our competitors.

Squadron: We were optimistic going into the meeting, because we felt this idea had real potential, but we were far from thinking it was a guaranteed thing. We knew the industry tends to move slowly with new things, and there was concern that the technology could be delivered in a live broadcast. The huge step forward was being able to do this in a live broadcast.

What surprised and pleased us about ESPN's reaction was that they immediately realized how popular and groundbreaking it could be. They weren't worried about the cost. The NFL deserves a lot of credit too, because they also immediately saw the value this would provide for fans.

But before Sportvision and ESPN could team up, they had to run the first-of-its-kind idea by the NFL for approval.

Drake: I remember showing it to [NFL commissioner at the time] Paul Tagliabue, knowing there were three possible outcomes. He'd either say it needs more work, no way, or this is good. He's a reserved guy, no jumping up and down. We showed him some demos and he said, 'This is good, this makes sense.' We all nodded our heads very seriously, then he left and closed the door and we all started jumping up and down.

Squadron: We actually initially had the line as a little more of an orange color. But the actual decision about the yellow hue was one Jed Drake made. We showed him the palette of colors and he decided.

With an exclusive agreement in place, the final step was to fine tune the technology to make it broadcast-ready — something that took longer than initially anticipated and delayed the new product's public debut.

Squadron: The last step before we were able to go to air was that the line was flickering enough that we had to hold off for a couple weeks to get that jitter off the line. Again to ESPN's credit, they wanted to wait to make sure it was really worth it.

Hank Adams (current Sportvision CEO): That line is actually a number of different systems working together to produce the ultimate effect. We laser survey the field so we actually have a three-dimensional map of it. We look through all the broadcast cameras, then stretch the field into place and have camera sensors that measure pan, tilt and zoom. As the camera pans and follows runners, we literally map the three-dimensional world onto your two-dimensional screen. Every pixel on your screen corresponds with a location on the field that we know.

Then we have a very sophisticated, green screen-like technology. We've advanced the technology to have multi-color inclusion and exclusion zones. The green, of course, is not monochromatic—it's brown, white, different shades of green. We pick out certain colors we know we're going to see — the shade of pants and uniforms — then exclude those so the line doesn't interfere. Drake: I remember telling Stan Honey, 'This has got to stop being a science project and turn into a broadcast technology quick. This was not an easy thing to pull off at that time. Computer processing was only a fraction of what it is now.

Adams: It probably cost the broadcaster $25,000-$30,000 for a weekend back then. We had to roll out an entire truck to make it work for games in the early days. It was five racks of equipment, a lot of engineers, a traveling circus. Now it's basically one computer, with maybe another to manage some of the UI. We can even downstream it now, not even being at the venue, just using computer sensors to figure out what the cameras are looking at and then drawing the line. When the line finally debuted on Sept. 27, it was an immediate hit with fans and a joyous occasion for the team that made it happen. Squadron: I was there in Baltimore in the truck for that first Ravens-Bengals game. It was a tense evening. You never knew when something could happen that could create a problem, and it was such an important night for us that we needed to go perfectly. It was tense the entire time, until the game ended. Then it was celebratory. Jim Delaney (an NFL fan for more than 35 years): I can't think of another digital innovation that has had as much impact on the fan viewing experience as that yellow line. Can you imagine trying to mark down and distance just with your eye now and those orange marker flags? Who the hell even looks at those things any more? I can't remember the last time I looked at the sideline to spot that orange flag. Forget the orange flag. Where's my yellow line? Robert Glasspiegel (an NFL fan for more than 50 years): You had to do it all in your head before. You knew roughly where they had to get to, but you had to do it all in your head or be dependent on the announcers saying, 'I think they got it' or 'I don't think they got it.'

Drake: After that first broadcast, I remember getting an email forwarded to me from [longtime sports producer] Don Ohlmeyer, who's been one of the preeminent guys in our industry for many, many years. He said, 'What you guys did last night really changes the entire presentation of football.' So that felt nice to hear coming from someone like him. Then of course there's the line I got from one of my friends so many years later. He took his young son to his first college football game and his son leaned over and said, 'Dad, dad, where's the yellow line? How come there's no yellow line on the field?' Despite its popularity, the yellow line didn't immediately become the ubiquitous piece of technology it is today. But it has had long-lasting reverberations for both sports fans and Sportvision. Adams: Every year we'd ultimately add more broadcasters and go deeper. There was a long time where you'd only see it on the national Fox college game, but not the local college-level games. Over time, you saw it creep in more. More games would have it, but it took five, six, seven years before it was on virtually every broadcast. Squadron: It was an enormous step forward for us. It was our first year of existence and it really established a very stable and exciting foundation for the company. It allowed us right out of the gate to demonstrate tremendous value for fans. It was so well-received from the beginning that it allowed us to raise more money, and it also made the point very powerfully that technology could be used to deliver a much better viewing experience for fans. Images: Tom Lynn/Getty Images, ESPN