Associated Press
In this Oct. 7, 2007 file photo, trainers cart Carolina Panthers quarterback David Carr off the field after Carr sustained an injury during an NFL football game against the New Orleans Saints, in New Orleans.

American football is a violent sport. That's not a profound statement. Anyone who watches the game understands it takes a certain amount of aggression and well-timed hitting to bring a ball-carrier to his knees, which is the only way to prevent him from scoring.

But there is a difference between hitting hard within the rules to prevent scoring and hitting hard with the deliberate attempt to injure. It's a difference not lost on Hollywood producers or film fans who are used to plot lines that pit fair-minded sportsmen against underhanded athletes who can't compete with skill but choose instead to play dirty. It's a distinction that can make the difference between a sport that attracts fans of hard-hitting competition and one that attracts fans with blood-lust.

With that in mind, the NFL's recent scandal involving coaches of the New Orleans Saints paying four-figured bonuses to players who cause an opponent to leave the game with an injury is an affront to sportsmanship. Contrary to the claims of apologists, this system was indeed different than those that reward a good, legal hit that causes a fumble or some other good fortune for one's team.

The real danger of such a system, however, goes far beyond the rarefied air of the National Football League. It extends through the college ranks to the thousands of boys who play high school football nationwide. They look to the NFL for inspiration. Popular pro players set the tone for the sport and, by their actions, define what is important and acceptable.

The reason to be concerned about this so-called bounty system is the same reason why former President George W. Bush felt it was important to address baseball's problem with performance-enhancing drugs in a State of the Union address. Plenty of evidence exists to show how high school athletes have been influenced to use such drugs, to the detriment of their own health. How much worse would it be for a teenage athlete to suffer a permanent physical impairment from a premeditated and calculated cheap shot on the football field?

NFL Commissioner Roger Goodell needs to find a way to deal with this issue forcefully and effectively, perhaps by suspending those involved in this scheme. Already, the league faces the challenge of dealing with former players who are bringing legal action, claiming league officials did little to protect them from vicious hits that gave them repeated concussions. It can hardly afford to appear indifferent to blatant attempts to elevate deliberate injuries above merely winning for the sake of winning.

Because of its nature, the sport always will walk a fine line that separates legal violence from cheap shots. That line does exist, however, and it is important.