Thirty-two cameras recently installed around the upper levels of each NFL stadium could change the way the game is officiated, analyzed and broadcast. This year’s automated line-to-gain measurements represent a single step in that transformation.
Following preseason testing last year and this year, the virtual measurements will make their official debut in Week 1. After balls are marked by human officials, on-field refs can call for a review, done in the NFL’s central replay hub. An operator there will use six 8K cameras to identify the ball’s location and confirm whether it reached the needed line to gain. The old-school chain gang will remain a sideline staple for the time being, there for players and those in the stadium to still use as an ever-present measuring stick, and for the league in case of tech failure.
Meanwhile, 12 additional 4K cameras have been added to each stadium, placed alongside boundaries and end lines to provide additional angles for review. Previously, the league relied on broadcast perspectives, limiting perspectives, particularly in non-marquee games.
Officials from the NFL and league partner Sony‘s Hawk-Eye say those deployments are part of a larger strategy that has brought 32 total lenses to each NFL stadium. Fourteen additional cameras won’t be accessible by teams or reviewers this season. Instead, they’re being used to test the potential of Hawk-Eye’s body-following Skeletrack technology for football in the years to come.
The full 32-camera system can capture 29 points on each athlete’s frame many times per second, adding to tracking data the league already gathers through sensors affixed to players’ pads and the ball.
The NFL first evaluated optical player tracking at the 2022 Pro Bowl, league deputy CIO Aaron Amendolia said. Additional use cases starting this year for the subset of 18 cameras helped the league justify the investment needed to equip its stadiums (including foreign venues on a temporary basis) with the tech required to begin gathering skeleton-level data and evaluating its usefulness. Some teams have long called for the installation of boundary-focused cameras specifically.
“Skeletrack was a conversation that we were having along with, ‘What could virtual measurement look like?’” RJ Paige, NFL senior manager of football business strategy, said. “But in order to get to that point, you have to start small. … Starting with those six cameras and then saying, ‘Hey, can we support our replay system and standardize replay with the boundary cameras by adding another 12?’ And that already gets us to 18 when we’re trying to get to 32 for Skeletrack. It’s killing three birds with one stone.”
Sony is also hopeful that the new measurement graphics shown in-stadium and at home generate their own moments of excitement as a virtual camera pans over a ball nearing a yellow line.
“It’s a great opportunity here to engage fans,” Sony’s Hawk-Eye head of North America Daniel Cash said. “Hopefully, the fans start to really kind of get into that.”
The feedback on virtual measurement could play a role in how quickly the league adopts more tech-aided officiating. Ball and player tracking could one day be used to assess whether laterals moved forward, where punts cross out of bounds and whether a quarterback was out of the pocket as part of determining if they committed intentional grounding.
For now, the league is intent on speeding up between-play decisions while maintaining accuracy. The virtual measurement system is expected to save up to 40 seconds per use compared to the chain gang, with reliable results to the quarter inch. Amendolia said the system should be faster in the regular season, when the league is working with the same set of broadcasters on a weekly basis. In addition, crews intentionally tested some measurements this preseason that were clear to the human eye, merely to get additional reps before Week 1.
“The focus of the officiating department has primarily been around how can we keep the game moving,” Paige said. The speed of Sony’s Hawk-Eye technology to pull together dozens of video feeds is what allowed the league to expand its replay assistance rules, he said, with replay officials able to advise on-field referees in real time. The league is also deploying smartwatches to four refs per game to transmit information more quickly, including the result of virtual measurements before they are shown on screen.
The data being gathered will likely have uses well beyond speeding up officiating. A test deployment of the cameras was used for ESPN’s digital altcast of a Cowboys game last season, for instance, as positional data helped turn players into The Simpsons characters.
“To have a system that can do both purposes, that’s the hard part,” Amendolia said. He previously said his team has brainstormed more than 100 use cases for optical tracking.
New forms of measurement often also expose pre-existing inexactitudes. Slow-motion, high-definition cameras have put a new emphasis on MLB baserunners briefly coming off a base, for instance. Hawk-Eye measurements down to the millimeter in tennis meanwhile have revealed cases where the physical court dimensions were actually off by a hair or two. Hawk-Eye cameras were used multiple times to rule on close replays during this year’s NBA playoffs as well. Perfecting the evaluation of one aspect of a sport often shows how much human element exists all around it.
All these games were designed well before fans had the ability to examine action frame by frame, looking for a misstep from players or officials. It’s something of a miracle that pre-existing rulebooks have held up under that level of scrutiny.
The NFL offers a particularly challenging testing grounds for data-based inference, given player pileups and a ball known for its oblong shape. It remains unclear exactly in what ways detailed, real-time player movement measurements could change the sport. But it certainly seems worth tracking.