Umm no one really cares about possession time. Why do people think this is what everyone is really after? Effective use of possession is what Corsi, xG are used for not raw possession time.
What do you mean no-one cares? The NHL is about to spend a lot of money to make the information available in some form. Someone must care quite a bit? The more information available to tell the story the better.
Possession time has hardly been studied at all in the public realm because of how time consuming it is to manually acquire the data. NHL Teams are paying companies to provide them this info right now. Why would they do that if nobody cared about it?
Anyway it's still a couple years away before we'll see it.
NHL pursuing new optical player tracking technology - Article - TSN
The NHL is scheduled to conduct its latest experiment there, this time using optical technology - which does not require infrared tracking chips embedded in player’s jerseys.
NHL commissioner Gary Bettman said the goal is to begin to work out the kinks in time to roll out a tracking system for the 2019 Stanley Cup playoffs.
“We’re actually working with some technology companies to get it into a position where we’re comfortable that it will work accurately and that it’s scalable for all games in all buildings,” Bettman said. “We think the ’19-20 season.”
The NHL last tested a player tracking system using infrared during the 2016 World Cup of Hockey in Toronto. The data delivered was believed to be extremely accurate - but the league backed off from pursuing that technology.
One issue was scalability and cost.
“It’s expensive,” deputy commissioner Bill Daly said. “Very expensive.”