With or without fights, the checking in professional ice hockey means that violence and injury-producing impacts are inherent in the sport. The N.H.L.’s handling of hits to the skull have come under scrutiny after scientists found that Bob Probert, former brawling hockey player who died last year of a heart ailment, had the same degenerative brain disease that prompted the National Football League to change some rules and policies in an effort to limit dangerous head impacts and disabling concussions. After a number of professional players sustained high speed hits to the head and were seen taken off the field on stretchers, football fans started questioning the violence in the “game.” The National Hockey League attempted to ban blindside hits to the head, but the move fell short of steps taken by other hockey leagues that have banned any contact with the head. I always thought all hockey players should wear helmets and mouth guards, as falls to the ice can cause teeth to be knocked out, fractured skulls and concussions.

What moves the professional sports leagues to action is economics. In the hockey arena, sponsorship dollars may cause greater change in the rules than scientific studies and doctors’ pleas. For example, Air Canada, a major N.H.L. sponsor, has urged the league to crack down on violence. Furthermore, a criminal investigation has begun in Montreal as the result of a hit that left a Canadiens player with a concussion and a fractured vertebra. To read more about the N.H.L.’s action in light of these recent developments, go to the New York Times Sports Journal coverage.