Upon completing their first lap around the boards, the skaters ditch the shavings in front of the open gate, where they are scooped and transferred into a gravel bucket that, Martindale said, is “at least 200 years old.” To finish, the skaters make a tight turn around the net and go up the middle of the ice. It looks, from up high, like a paper clip.

“Pushing a shovel is pushing a shovel, whether you do it on foot or you do it on ice — I give you the pattern, and you do it,” Martindale said in a recent interview. “But the French thing is the classy thing, and they’re always worried here. ‘Frank, do you think it’s going to look classy? Do you think it’s going to look good on the ice?’ I said, ‘Guys, we’ll make sure.’ ”

Watching it all from the league office in Toronto, where real-time feeds focus on the ice during commercial breaks, Murphy cares little about the visual appeal. He monitors a crew’s overall performance — its promptness, efficiency and so on — while making sure that players do not obstruct the process. If a goaltender lingers too long in a crease, for instance, Murphy might contact the team’s general manager. The on-ice officials also assess a crew’s skills in the report they file after every game.

“As long as everything’s quiet, that means everything’s good,” said Scooter Fruik, the ice manager at Bridgestone Arena in Nashville.

Jennings said he had not received any complaints from the league. But for his own documentation, he keeps a detailed report for every game. It logs, among other things, the time elapsed between each stoppage and how much loose ice was collected. During every shift, the crew deposits the shavings in four 20-gallon cans at each corner of the rink. Those cans are then emptied into a 44-gallon receptacle, which can be anywhere from a quarter to three-quarters full after each shift.

On a recent night, a snowstorm thinned Jennings’s ranks, leaving his crew two short. Even after a crisp pace to the opening period created nearly nine minutes’ worth of amassed shavings, the group managed to clean the ice in 1:51.