Nearly 20 years ago, ESPN, the sports broadcasting network, began displaying a yellow virtual first down line when broadcasting football games on television. Developed by Sportvision, a small Silicon Valley company, that yellow line initially mystified fans: “Is it on the field, or not?” millions of viewers wondered.
These days, we can’t imagine watching football on TV without knowing exactly where that first-down line is. And that technology spawned a host of virtual graphics that augment sports action for onscreen viewers—most recently, the America’s Cup races. (Sportvision founder Stan Honey detailed that technology in “The Augmented America’s Cup.”)
Tonight, a new virtual line hits the TV screen: a virtual 3-point line for basketball, debuting with the tipoff of ABC's primetime broadcast of a National Basketball Association game pitting the San Antonio Spurs against the Cleveland Cavaliers. Unlike football, where the line indicating how far a team has to advance the ball in order to earn a fresh set of downs is constantly moving, the 3-point line is painted on the basketball court and never moves. But after the Golden State Warriors won last year's NBA championship and rattled off 24 consecutive wins this season before suffering their first loss—feats in no small measure due to the long-distance shooting wizardry of Warriors point guard Stephen Curry—ESPN decided to put 3-point shots in a virtual spotlight and make it clear immediately whether any attempt is successful.
The network’s “Virtual 3” technology lights up the line for every 3-point shot attempt. The illumination is turned off immediately if the player misses; if the ball goes in the basket, the line remains lit up until the ball is handed over to the other team. ESPN developed the technology in house, at the company’s Princeton Visual Technology Lab.
According to an interview with Jed Drake, ESPN’s vice president of production innovation, that was published on the company’s media site, creating the virtual line was a tricky proposition. Unlike the first down line in football, there is an existing 3-point line in the real world, so the virtual line must mask it exactly—and it can be just a few pixels wide when seen on screen. And, Drake said, the curve of the 3-point line added a challenge (though, to be fair, a football field has curves the virtual yellow line must also follow).
There have been recent advances in technology that allow cameras to be tracked through video analysis instead of the use of on-camera sensors. These, say experts, could make implementing augmented video features for sports productions cheaper and easier. But according to Ken Milnes, who worked on much of Sportvision’s groundbreaking technology and is now a consultant, technological advance was not likely the impetus to this new development. Rather, he said, it’s the need to help the producers tell a particular story—and the Warriors’ success in 3-point shooting is definitely the story in basketball these days.
ESPN’s Drake confirms that bringing the 3-point line from idea to implementation was an eight-month project. Do the math: it’s been just about eight months since the beginning of the 2015 NBA finals that the Warriors won, in large part due to Curry’s 3-Point shooting.
Coincidence? I doubt it.
So, if you’re watching today’s Spurs-Cavaliers game, be sure to take notice of the
Virtual 3 “Curry” line.
Tekla S. Perry is a senior editor at IEEE Spectrum. Based in Palo Alto, Calif., she's been covering the people, companies, and technology that make Silicon Valley a special place for more than 40 years. An IEEE member, she holds a bachelor's degree in journalism from Michigan State University.