Hockey's Impact On Football

It's hard to imagine football - NFL or CFL - without the first-down line being superimposed onto the field. Along with the first-down line, the football television crews also superimpose the line of scrimmage onto the field, but it's pretty crazy to think that the first-down line first appeared in 1998 - some twenty years ago! Now this isn't Football Blog In Canada, so why am I talking about first-down lines? Would you believe that technology came from hockey?

See that little glowing beam to the right? Fox Sports introduced the FoxTrax puck to help viewers in the United States track the puck on the ice. It was first used at the 1996 NHL All-Star Game as shown to the right, but let's just say that it was hated. David Hill, Fox Sports' top man, led the crusade to have the FoxTrax puck put into games, and electrical engineer Stan Honey made it happen. Being universally panned by hockey fans, it was retired after the first game of the 1998 Stanley Cup Finals when Fox lost rights to broadcast the NHL.

See the similarities in the above images? If you're thinking that Fox simply transferred the technology to football, you'd thinking correctly. Ethan Trex from Mental Floss writes,

"According to Allen St. John's 2009 book The Billion Dollar Game: Behind the Scenes of the Greatest Day in American Sport - Super Bowl Sunday, the first-down line actually emerged from the ashes of one of sports broadcasting's bigger debacles: the FoxTrax system for hockey, which was designed by a company called Sportvision. FoxTrax — which hockey fans no doubt remember as the much-maligned 'technopuck' that debuted in 1996 — employed a system of cameras and sensors around a hockey rink to place a little blue halo around the puck."

So you're probably thinking about how it went from what looked like a laser blast off a stick to a stationary line on a football field, but remember that the last time we saw the FoxTrax puck was in May of 1998. The NFL football season starts much later, and Mr. Trex writes,

Sportvision debuted its 1st and Ten system during ESPN's broadcast of a Bengals-Ravens tilt on September 27, 1998. A couple of months later, rival company Princeton Video Image unveiled its Yellow Down Line system during a Steelers-Lions broadcast on CBS. (Sportvision is still kicking, and ESPN acquired all of PVI's intellectual property in December 2010.)

How crazy is it that they transitioned the failed hockey technology to football in the span of five months? The technology is rather insane, but it has literally become an integral part of football broadcasts today, and how that line is created was derived directly from the FoxTrax computer system.

The FoxTrax system worked as follows as per its Wikipedia page:

"The puck emitted infrared pulses that were detected by cameras, whose shutters were synchronized to the pulses. Data from the cameras was transmitted to a production trailer nicknamed the 'Puck Truck', which contained SGI computers used to calculate the coordinates of candidate targets, and generate appropriate graphics on them."

All of that information brought back some memories of watching games with the FoxTrax puck, but the computers needed to calculate all the information being fed back to it was rather impressive.

To create the first-down line, Fox and ESPN have taken this technology to a whole new level.

"Long before the game begins, technicians make a digital 3D model of the field, including all of the yard lines.... These models of the field help sidestep the rest of the technological challenges inherent to putting a line on the field. On game day, each camera used in the broadcast contains sensors that record its location, tilt, pan, and zoom and transmit this data to the network's graphics truck in the stadium's parking lot. These readings allow the computers in the truck to process exactly where each camera is within the 3D model and the perspective of each camera. (According to How Stuff Works, the computers recalculate the perspective 30 times per second as the camera moves.)"

In other words, the preparation for each game literally takes place long before the broadcast even begins. The fact that the computers in the network's graphics truck recalculate the perspective 30 times per second make it a seamless animation to the eye - similar to cartoons! That's pretty impressive technology, but that's just the tip of the iceberg.

"When you watch a football game on television, you'll notice that the first-down line appears to actually be painted on the field; if a player or official crosses the line, he doesn't turn yellow. Instead, it looks like the player's cleat is positioned on top of an actual painted line. This effect is fairly straightforward, but it's difficult to achieve.

"To integrate the line onto the field of play, the technicians and their computers put together two separate color palettes before each game. One palette contains the colors — usually greens and browns — that naturally occur on the field's turf. These colors will automatically be converted into yellow when the line is drawn on to the field.

"All of the other colors that could show up on the field — things like uniforms, shoes, footballs, and penalty flags — go into a separate palette. Colors that appear on this second palette are never converted into yellow when the first-down line is drawn. Thus, if a player's foot is situated 'on' the line, everything around his cleat will turn yellow, but the cleat itself will remain black. According to How Stuff Works, this drawing/colorizing process refreshes 60 times per second."

That is rather impressive from a technology perspective, and it actually makes a lot of sense to keep things separate on the two color palettes despite it requiring a pile of work. But rather than having players cross through the line, they cross over it as if it's part of the field. Remember that the FoxTrax puck glowed no matter where it was on the ice - behind the boards near the camera, behind players, in the crowd. The technology wasn't set for two color palettes in the NHL, so this is an innovation that football broadcasts needed.

As Mr. Trex wrote in his piece, this cost to the broadcasters to have this technology originally in 1998 was somewhere between $25,000 to $30,000 per game with a staff of four people watching over five racks of equipment. Today, he notes, the entire operation can be pulled off with "[o]ne technician using one or two computers" and, according to Sportvision, "some games can even be done without anyone actually at the venue."

And to think this all started with a glowing puck.

There are innovations that cross over to other sports that have had major impacts, but it's hard to imagine football without the first-down line being superimposed on the field. Would football have found this technology if the FoxTrax puck remained in existence? It's hard to say, but you'd think it would have found its way into football eventually.

I guess it's true what they say: one league's trash is another league's treasure!

Until next time, keep your sticks on the ice!