How puck, player tracking works
by Andrew Podnieks|24 MAY 2023
Hockey is a game that both respects its traditions and history on the one hand and is constantly evolving on the other. To the latter point, the IIHF has adopted puck and player tracking, which has revolutionized the way the game is presented and explained to fans in the arena and at home watching on television.

The information garnered from this technology is quirky, informative, enlightening, important. But it all begs the question, ‘How does it work?’ The concept of tracking might be easy for people to grasp, but the technology is anything but.

“The IIHF player and puck tracking system consists of a puck, with the chip inside, the tag on the player, which is attached to the shoulder pad, and antennae in the arena which act as receivers of the data,” explained IIHF Sport Director Christian Hofstetter. “The antennae use Bluetooth technology. They are placed around the field of play, so it doesn’t capture anything the puck does in the stands.”
That part is simple. Embed a tracker in the puck and shoulder pad…and then what?

“The chip will show the movement and position of the puck on ice at all times, so it’s important the officials don’t have any other puck in their pockets,” Hofstetter continued. “The chip can track the speed of the shot, track passes between players, track the distance a puck has travelled. The information on players is similar—distance travelled, time on ice, and, of course, information on when he shoots or passes.”

The IIHF used the men’s U18 in Germany last year as the pilot project for the technology, and it worked so well it has been using it for all top-level events this past season, culminating with the current Men’s World Championship in Riga and Tampere.

“We are always trying to use new and innovative technology to help make the game more accessible,” Hofstetter added. “Our sport is fast. Not everyone sees what’s happening on the ice, so this is an opportunity to bring the sport closer to the fans and show them how things work and help them better understand our game. The data is shown on our website and used on social media, but it is also used to help our broadcasters make the game more lively and more interesting. The data can also be used by teams to help the performance of their players, both individually and as a team. We are always trying to find new ways to enhance and present our sport, and this data is a valuable tool for that.” 

The IIHF is not alone in embracing these new initiatives. This tracking system is also used in the Finnish league and the DEL in Germany, and by some teams in Switzerland. “It is maybe more interesting to us at the IIHF because you can use the data to compare players and teams from around the world,” Hofstetter suggested.

Okay, that’s the big picture, but what about a little tech talk to further explain what’s going on with these little gadgets? Okay, well, the chip and tag transmit their location—their x, y, z coordinates—every 20 milliseconds, so there is an enormous amount of data. You can see the players who are on the ice, so you can get a good understanding of their position, and see clearly who has the puck. 

In addition, you can receive information on the puck’s average speed, the distance each player has travelled, the total distance the puck has travelled. The IIHF can also track puck control, so they can see who has it for longer. They can then break all of this down for each player. You can also see the length of any shift, and if you hover over that information on screen, you can see who was on the ice at the same time. 

Further miscellaneous information for fans. When a puck goes into the crowd, the technology can track its location very easily. The tracking system is based on low energy Bluetooth technology. There are locators connected to a closed network in the building, and as long as these locators can receive a message from the tags (“see” them, in essence), the players and the chipped pucks can be located. 

In terms of geography, tracking recedes pretty quickly the further you get from the ice, even inside the arena. A puck in a team dressing room, for instance, couldn’t be found. However, the low-energy requirement of these tags means the battery lasts a very long time, so a puck in the arena within range could be located for probably three to four years after the battery is fully charged.

For fans who notice that linesmen swap pucks frequently during a game, this is not about the tracking system so much as it is about the IIHF’s “Frozen Puck Procedure” that is defined in the IIHF Sport Regulations.  The pucks are frozen to -10C, and a new puck is put into play usually every two minutes of game action. 

Although the IIHF is happy to share as much information as possible about the tracking system, there is one thing it can’t share. Just as no one quite knows how you get the caramel in a Caramilk bar, no one knows how the chip is inserted into the puck. It is, for real, a trade secret that is closely guarded. However, every puck is weighed and balanced to make sure it meets the IIHF’s standard puck specifications.

Just as with any old-style puck, the tracking puck is pretty indestructible. It’s not going to chip or split any time soon. Besides, the IIHF removes pucks from circulation that show any sign of damage. Chips can fail, yes, but every puck that is scheduled to be used on a given IIHF game day is tested for battery strength in the morning. Pucks with less than 25 per cent battery life are removed from inventory as a precaution. Less than 5 per cent of the total inventory of pucks will be removed due to low battery over the course of the Men’s World Championship, and perhaps two or three pucks will fail over the course of 64 games. The IIHF’s IT people know immediately when a puck is no longer sending data and will swap the puck at the next whistle.

There you have it. The alpha and omega of the IIHF’s sophisticated and important puck and player tracking system. Fans enjoy it, and teams employ it all in the name of development.