Gorra grew up playing hockey in Connecticut and now works as a pediatric surgeon. New to Fresno last year, he helped coach a team in a local youth league, named for and sponsored by the Fresno Monsters, a North American Hockey League junior team for boys 16 to 20.

Talented teenage players from across the continent are attracted to places like Fresno and dozens of leagues like the N.A.H.L. because of the promise of college scholarships and possible professional careers. Fighting, for now, is part of the game.

It was during a family skating event that Gorra, 36, came face-to-face with the conflicted state of junior hockey. His son and the 7-year-old son of a friend pantomimed what they had seen among teenage Monsters players. They circled each other in the widely recognized choreography of a fight’s preamble. The two fathers rushed to intervene.

“To see a 5-year-old do that, especially my own son, I was blown away by it,” Gorra said.

The Monsters, for a short time a couple of years ago, cast spotlights on their players as they traded blows. This month, the team was involved in a “line brawl,” where players, even goalies, paired off to fight. Some N.A.H.L. rivals still feature bare-knuckled teenagers on the banner of their Web sites.

The N.H.L. and most professional minor leagues in North America, while working to address blows to the head during the course of game action, have shown little appetite for altering rules to reduce fights. (There have been about 400 N.H.L. fights this season, occurring in about 35 percent of games. For most top junior leagues, the per-game rates are often double or more.)

In the past few years, four brains of deceased N.H.L. players have been found to have chronic traumatic encephalopathy, or C.T.E., a progressive disease caused by repeated head trauma. The most striking case involved the Minnesota Wild and Rangers enforcer Derek Boogaard, who died in May at 28 of an accidental alcohol-and-painkiller overdose. Like many others later found to have had C.T.E., including dozens of former football players and boxers, Boogaard showed early signs of dementia. Two other N.H.L. enforcers died last August, in apparent suicides.

N.H.L. Commissioner Gary Bettman said the three deaths were a coincidence. Last fall, he said the league’s healthy attendance figures showed that fans did not want fighting banned, and he cast doubt on the science linking hockey fights to brain damage.