Nothing heats up hockey fans like an argument about dropping the gloves—a tradition with a long, bloody, and bizarre history.

1. The NHL’s Official 1922 Rule Book Referred to One-on-One Fights as “Fisticuffs.”

Such skirmishes, the league determined that year, would usually result in penalties instead of automatic ejections.

2. Not Every League is OK with fighting.

American players have to turn the other cheek in college: the NCAA punishes fighters by ousting them from both their current game and their next one. Meanwhile, scraps are strictly banned in both the Olympics and European hockey leagues.  

3. NHL Smack-Downs Peaked in the Early '80s.

An average of 1.17 violent altercations per game erupted during the record-setting 1983-84 season while 2013-14 had to make do with a pedestrian .38.

4. One Infamous Junior Brawl Raged On in the Dark

Things got ugly during 1987’s World Junior Ice Hockey Championship final game. Theoren Fleury scored Canada’s opening goal against the Soviet Union and celebrated by turning his stick into a prop machine gun and “firing” on the U.S.S.R. bench. This showboating irked his opponents, who grew even more frustrated when Canada claimed a 4-2 lead halfway through the contest. Slowly but surely, hostilities mounted.

With a little over 6 minutes left in the second period, Russian player Sergei Shesterikov smacked into Canadian Everett Sanipass. As they traded punches, Fleury got into his own tussle, and a bench-clearing slugfest ensued. The carnage raged on for nearly 20 minutes, even after officials tried turning out the arena’s lights in a hopeless attempt to restore order. Finally, the game was nullified and both countries were ejected from the tournament.

5. Fighting Declines Significantly During the NHL’s Playoffs

When Lord Stanley’s Cup beckons, teams tend to clean up their act. Over the past 20 years, the average NHL post-season has seen roughly one-fifth as many brawls as the preceding regular season.

6. Some Historians Blame the Invention of Blue Lines for Encouraging Clashes

These lines, which effectively trisect regulation hockey rinks, help referees recognize when a player’s made an illegal maneuver. But have they caused more harm than good? By restricting certain movements, many believe that the blue lines—introduced in 1918—sparked a new level of physicality and aggressiveness.

7. Former Presidential Hopeful Tim Pawlenty Claims Hockey Fights have Helped His Political Career.

You don’t attack team captains.” “Don’t pick a fight with someone well below your weight class.” “Never check someone from behind.” Players, fans, and journalists can talk your ear off about pro hockey’s unwritten fighting rules. Apparently, Tim Pawlenty, an ex-Minnesota governor, enjoys the “order beneath [this] chaos.” “I apply some of the unwritten rules of the ‘code’ in negotiations and dealings with political opponents,” he says. “If you give your word, you’ve got to keep it …sometimes it’s up to you to enforce those agreements.”

8. Occasionally, Referees Participate.

In 2013, when a Slavic ref got smacked, he threw down his helmet, and proceeded to duke it out with an unruly Russian player. Less comically, one Swedish official came under fire 11 months later after dragging forward Marius Holtet onto open ice and putting him in a choke hold!

9. Not Even Charity Games are Safe From Bouts.

Since 1974, teams assembled by the NYPD and FDNY have been facing off in hockey games to help support various charities. But good causes don’t always necessitate good behavior. Last year, New York’s finest handed Big Apple's firefighters an 8-5 loss, but it was the contest’s epic rumble that made headlines: 25 minutes elapsed before play resumed and, at one point, virtually every non-goalie player on both teams entered the fray.

10. There May be a Statistical Correlation Between Fighting and Team Productivity

Economic research analyst/die-hard hockey buff Terry Appleby claims that, after a bout, there’s a  76 percent chance of at least one team upping the ante and creating more scoring opportunities for themselves within the next three minutes (though, by his own admission, he’s not yet sure if this translates into actual goals and/or wins).

11. Fighting’s Been a Part of Hockey Culture Since (At Least) the 1870s.

On March 3, 1875, spectators gathered at a Montreal skating rink to witness “a novel contest on the ice.” This became the first indoor hockey game in recorded history and—fittingly—it came with a shoving match. The fast-paced sport didn’t sit well with certain repeat customers, who felt their rink was getting needlessly scratched up. They confronted the players about it and, lo & behold, fists started flying. Go figure.