Fighting is a part of hockey.

A smaller part than it used to be, certainly. One look at the numbers showed a 40 percent decline in the number of fights between the 2012-13 and 2015-16 seasons. Going a bit further back, more than 42 percent of all games had fights in 2001-02. That number was 23.4 percent in 2015-16.

Whether fighting should be a part of hockey is a question for others. Those who argue in favor of fighting have their reasons, and those reasons have been studied.

As the use of advanced analytics has exploded across the sporting world, some assumptions about fighting in hockey have been challenged, their validity questioned. We’ll take a look at some of that research.

But first …

What Are the Arguments?

Those who favor fighting in hockey tend to stake out one or more of these reasons:

• It keeps players safe: Take away fighting, there’s no consequence for one player taking a run at another.

• It motivates your team: Win a fight, start outplaying your opponent.

• It gives the people what they want: People watch hockey for the fights, just like people watch NASCAR for the crashes.

Efforts to divine the legitimacy of those positions have spawned some interesting results.

Without Fights, More Violence?

So the theory goes, “enforcers” keep stars healthy. A punch in the mouth is more likely to prevent a cheap shot than a trip to the penalty box.

A 2016 study by authors from West Virginia University and Northeastern University — with the weighty title “Community and Specialized Enforcement: Complements or Substitutes?” — sought to test that hypothesis. Nearly 7,000 games from 2007 through 2013 were analyzed.

If anything, the study suggested a need for more consistently tight officiating. Concerning egregious hits (boarding and cross-checking as opposed to hooking and tripping), the authors wrote “penalties significantly reduce hitting beyond the impact attributable to fights.”

It was found that hits per minute spike in the time before an egregious penalty, then drop for more than 3½ minutes thereafter (beyond the power play) before returning to normal game levels.

However, as a member of the pro-fight camp would certainly note, where periods of increased hits continue without a penalty call, hits spike further until a fight erupts — after which hits immediately return to normal game levels.

Punching Up Your Scoring

Does winning a fight help a team win a game?

A Georgetown University study suggests it does not. Perhaps equally interesting, its study of 342 fights from the 2012-13 NHL season suggests NHL teams don’t think fights help.

If they did, it follows that the trailing team would, during the course of a game, send a goon out to start and win a fight, thus swinging momentum. Using the fight rating system of hockeyfights.com to determine fight “victors,” the Georgetown study found the share of goals scored before the fight by the fight-winning team was larger than that of the fight-losing team.

As for the aftermath of a fight, Georgetown sliced the data four ways. Considered were all fights, “good” fights (earning a rating of more than 5 by hockeyfights.com voters), fights with clear winners (again as determined by the website) and good fights with clear winners (a combination of the middle two categories). In every category, the percentage of goals scored by the team winning the fight was lower from the end of the fight to the end of the period in which the fight occurred than it was from the start of the game to the start of the fight.

In short, the study concluded, “there was no tangible evidence that winning fights affected the outcome of hockey games …”

That’s Entertainment?

Fans love fighting, right? So teams that fight a lot should draw well, and teams that stop fighting should see a spectator exodus — at least theoretically.

According its research in 2014, The Hockey News found roughly 40 instances where teams either increased or decreased their fighting rate by at least 50 percent from one season to the next. Teams that fought less saw a slight (roughly 2 percent) attendance increase. To a lesser degree, teams that fought dipped a bit at the turnstiles.

Author bio: AJ Lee is Marketing Coordinator for Pro Stock Hockey, an online hockey shop offering pro stock hockey equipment. He was born and raised in the southwest suburbs of Chicago, and has been a huge Blackhawks fan his entire life. AJ picked up his first hockey stick at age 3, and hasn’t put it down yet.