Updated

For a preview of what evidence on Day 1 of an NHL concussions trial might look like, head over to YouTube, type in "NHL brawls" and take your pick of any of the 481,000 choices offered there.

In a league where both sides give a wink to bare-fisted fighting — and in a case in which raw emotion could play as big a role as the still-developing science of concussions — it will be hard for either the players or the NHL to claim the moral high ground.

A group of 10 retired players, seizing the moment in wake of the $765 million settlement the NFL recently offered its concussed retirees, filed a class-action lawsuit on Monday. They claim the league hasn't done enough to protect players from head injuries.

They'll certainly present a compelling case based in part on decades of head-jarring contact via body checks into the boards, unbroken tumbles to the ice and, yes, all those punches to the head that so many claim are a necessary part of the game.

Meanwhile, the NHL has promised a vigorous defense. It claims to have been well ahead of the pack when it comes to mitigating head injuries. And, in fact, when compared to other pro leagues — especially the NFL, which spent decades pushing off legitimate scientific research in the face of compelling evidence — the NHL could be considered a trendsetter.

In 1997, the NHL joined its players' union and team medical staffs to create a concussion working group. The league was the first to bring baseline testing into play to better diagnose concussions. It was the first to create "quiet rooms" where a test could quickly be given after violent head contact. In 2010, it began penalizing and suspending players who targeted an opponent's head.

But as the YouTube search or any scan of the evening's box scores will attest, the league has never put its foot down on fighting. Its most frequent discipline remains a 5-minute stay in the penalty box for the sort of assault that would cost a college or Olympic player a game or more, and could very well land an average fan in jail.

Commissioner Gary Bettman recently called fighting a "thermostat" that helps cool things down when tensions get high.

"We can all hurt someone every shift if we want to," said 43-year-old right wing Teemu Selanne of the Anaheim Ducks, who recently lost several teeth when inadvertently hit in the face with a stick. "The players are so strong, so fast. There has got to be a lot of intelligence involved in this game."

Maybe. But no one has ever looked brilliant while pulling a hockey sweater over another guy's head and pummeling him.

Keith Primeau paid a heavy price for being part of that culture. The former Philadelphia Flyers captain, who is not part of the current lawsuit and had no comment on the legal action itself, retired in 2006 after at least four concussions he knew of.

But even he admits there's some merit to hockey's on-ice justice system, saying, "There is some truth to the statement that the players need to be able to police themselves."

Nice to see the players and the league can agree on something. But good luck trying to get a jury to parse the differences.

The first week of the NHL season may explain why both sides are so reluctant to take on the issue.

On opening night last month, hockey made a splash of sorts when Canadiens enforcer George Parros fell gruesomely during a fight, face-first into the ice and had to be taken off on a stretcher with a concussion.

A night later, Patrick Roy, whose fighting skills were dwarfed only by his goaltending ability back in the day, made news not so much because he won his coaching debut in Colorado but because he received a game misconduct after trying to pick a fight with the opposing coach, Bruce Boudreau.

He's "going to be in for a long year, if he's going to yell at every player and yell at the refs at every stoppage of play," Boudreau said. "It's not the way the game is played."

No, but it got hockey in the headlines at a time of year when only folks in Detroit, Chicago and Canada are usually paying attention.

While nobody endured serious harm from Roy's antics, and Parros is back on the ice again, there have been far more dire consequences when hockey's inability to solve things peaceably gets out of control.

In a different lawsuit, the family of Derek Boogaard is suing the NHL for wrongful death, claiming the league is responsible for the brain damage and addiction to painkillers Boogaard suffered over his six-year career as one of the league's top enforcers.

Boogaard died of an accidental overdose of pain medication and alcohol two years ago. The lawsuit says he was posthumously diagnosed with chronic traumatic encephalopathy (CTE), a degenerative brain ailment that can be caused by repeated blows to the head. CTE and its prevalence among NFL players played a big role in that league's recently settled lawsuit.

"He was there protecting his teammates at all costs," Boogaard's mother said on the day the lawsuit was filed. "But who was there to protect him?"

The correct answer: Nobody.

And who, exactly, is to blame for that? In the NHL, as these upcoming lawsuits are likely to show, it's all parties involved.

___

Eddie Pells is a national writer for The Associated Press. Write to him at epells@ap.org or www.twitter.com/epells