The NFL uses sensors on players, in the football to give viewers key data
Feb 09, 2024As the San Francisco 49ers and Kansas City Chiefs face off in Super Bowl LVIII in Las Vegas this weekend, it marks the 10th year that the National Football League (NFL) has used RFID sensors to obtain data used for teams and their broadcast partners.
The use of player data by teams going past offensive and defensive statistics such as passing yards and tackles has been expanding in the NFL in the last decade. The UWB technology has been employed at all NFL games and used for NextGen Stats since 2015.
The use of hardware from Zebra Technologies is part of a league-wide trend to use UWB to help with player performance–the company’s MotionWorks has been adopted by about one-third of teams in the league to detect the movement of players during practice.
Mining Key Data
The technology is intended to provide real-time player data and analytics based on speed, distance, accelerations and decelerations, says Dominic Russo, Zebra Technologies’ football command center specialist.
Each player wears two UWB tags in their shoulder pads, while defensive-line players have a third tag attached to the center back of their shoulder pad so that their position can be captured and properly triangulated, even in a downward stance. Each player has a unique tag ID linked to the MotionWorks software.
The UWB tags transmit signals in the 7.5 GHz frequency band to Zebra's anchors at a distance of up to 325 feet. The anchors measure the time distance of arrival (TDOA) data to determine the tag's precise location via X and Y linear position.
Stadium Operations
A tracking system is installed in every NFL venue where a game is played, composed of 20–30 ultra-wide band receivers; the RFID tags installed into the players’ shoulder pads; and RFID tags on officials, pylons, sticks, chains, and in the ball.
Altogether, an estimated 250 devices are in a venue for any given game that requires three operators to confirm that all tracking systems are functioning properly on game day.
The tracking system captures player data such as location, speed, distance traveled and acceleration at a rate of 10 times per second, and charts individual movements within inches. The raw data is used to automate player participation reports, calculate performance metrics, and derive advanced statistics through machine learning on Amazon Web Services (AWS).
More than 200 new data points are created on every play of every game, such as distance traveled and max speed.
Tracking Players
According to Zebra officials, MotionWorks can pinpoint the location of players and tagged balls within about six inches. The technology captures tag location 12 times per second for players, and 25 times a second for balls.
The NFL’s Next Gen Stats technology, tracking process, and data are the results of years of testing between the league that started in 2014 with Zebra and Wilson, makers of the league’s footballs. In 2017, the NFL and AWS ventured into advanced analytics, leveraging AWS machine-learning technologies.
Using MotionWorks, high-speed player data is captured and converted into real-time usable stats, including:
- Coaches using the data to make changes, in real-time, to each play;
- Using algorithms, player stats are displayed in real-time; and
- The technology is easily integrated with graphics systems so it can be used during live broadcasts as well as replays.
Football Follies
Getting tags into the Wilson footballs proved to a complicated journey. A football is an inflated bladder covered by cowhide. The RFID tag, first piloted in 2016 and used in all games since 2017, is around 3.5 grams and the sensor is suspended in the bladder—on the side opposite the valve where the ball is inflated.
With the average lifespan of an NFL game ball is around six games, league and company officials said the tags worked well enough that the balls were out of circulation before the tag’s battery wore down.
The games balls are then used for practices, where they can be used for another year or two, before the battery is no longer charged.
Broadcast Use
Jim Nantz, Tony Romo and the rest of the CBS Sports broadcast team will lean on the league’s Next Gen Stats to analyze trends and player performance to game telecasts. They include how fast a player goes on a single play or how many yards a quarterback scrambled to avoid the rush.
Having the league’s media partners use the data obtained to better inform its fans was at the forefront for the league.
“We wanted to get information online, for broadcasts and data for fans,” Matt Swensson, head of products and technology for NFL Media, said. “Many uses are behind the scenes. If we wanted to identify every player JJ Watt lined up against and got to the quarterback against, we could do that. It’s very helpful when we’re putting together highlights.”
Key Takeaways:
- The UWB technology has been employed at all NFL games and used for NextGen Stats since 2015.
- The tracking system captures player data such as location, speed, distance traveled and acceleration at a rate of 10 times per second, and charts individual movements within inches.
