In March, he broke the record for most games coached in the American Hockey League. (He now has 1,344, all with the Sharks’ top affiliate.) He is 20 victories from becoming the A.H.L.’s career leader, passing the Hockey Hall of Famer Fred Cook, known as Bun, who had 636 from 1940 to 1956.

That many victories in the N.H.L. would put Sommer in the career top 10, ahead of the likes of Jacques Lemaire, Darryl Sutter and Toe Blake. But over nearly 20 years, Sommer has been passed by each time the Sharks have changed head coaches. This year, when Todd McLellan left and Peter DeBoer was hired, Sommer was not interviewed.

Sommer does not complain, but he does wonder. N.H.L. coaches are increasingly buttoned up, standing sternly behind the bench in their stylish suits, imparting clichés and misdirection to the cameras.

Sommer, son of a tugboat operator, raised in Oakland by a single mother, is a blue-collar teacher most comfortable in flip-flops and straight talk. He is a loose Californian in a Canadian game. “Oh, man,” and “I was like, seriously?” are two phrases that pepper his speech.

On a bus trip each season, Sommer has players watch “Lonesome Dove,” the six-hour mini-series about an epic cattle drive. (“They’re kind of a team, these cattle ranchers,” Sommer said.) He takes his team on overnight camping trips, discerning who leads and who follows. To keep things light, Sommer dresses up extravagantly on Halloween and holds ugly sweater contests. He once instructed players to wear suits they could find at secondhand stores for under $10.

His 24-year-old son, Marley, who has Down syndrome, is Sommer’s sidekick at the arena, helping in the dressing room, even singing the national anthem, and is hugely popular with players.