I’ve always joked that Canada is just a version of the United States that decided to be 10 percent different. We both use dollars, but their loonie is worth a tad less than our buck. We have similar accents—resembling each other more closely than any other English-speaking language accents—but there’s something aboot Canadian accents that’s a little bit off. We’re two of the few countries on earth to celebrate Thanksgiving, but while Americans will gather around the turkey Thursday, Canadians had their Thanksgiving a month and a half ago, on the day that’s federally recognized in the U.S. as Columbus Day.

This week, we will both celebrate another of our biggest similarities: football. On Thursday, Americans will watch the wildly popular Thanksgiving Day games; on Sunday, Canadians will watch the Grey Cup, the Super Bowl of the Canadian Football League. Americans can watch the Grey Cup too, as the matchup between the Ottawa Redblacks and the Calgary Stampeders will be broadcast Sunday at 6 p.m. ET on ESPN2. This is a no-go for most American football fans, though, as it falls right in the middle of the Week 12 NFL slate. But every year, I make a point of prying my eyes away from the teams I watch every other fall week to catch the biggest game in the world’s second-biggest professional football league.

Canadian football, like everything else about Canada, is different in the details from the U.S. version. Twelve players line up on each side of the ball instead of 11. Teams are allotted just three downs per series instead of four. There’s a three-minute warning instead of a two-minute warning. The field is 110 yards long, so midfield is the 55-yard line. See, 10 percent different.

And those differences are the appeal! Watching this game feels like looking at football in a fun-house mirror. The rules of Canadian football are what you’d get if aliens came to America, took in one NFL game, and scribbled down studious notes in hopes of recreating the game on their planet … but the notepad tumbled out of their spaceship as they flew away.

I hope some of my American compatriots will join me in watching our Northern neighbors play the championship of maple syrup football. If this will mark your first time watching the Canadian iteration of the sport, here are some key quirks to look out for:

• Canadian football games don’t end when the clock hits zero. The clock hits zero, and then there’s one more play, and then the game officially ends. The most confused I’ve been watching Canadian football came at the end of the first Grey Cup I watched. The winning team was in kneel-down formation, and the final seconds were ticking off the clock. But nobody was rejoicing. Seven … six … five … four ... Why were the players standing around in position to run another play? Three … two … one … Why wasn’t anyone dumping Gatorade on the victorious coach? Was it because it was cold, and it would have been a bad idea to douse a coach? Were Canadians just that polite? What was going on?

I actually like this rule better than what we have in American football. So often the final play of American games is a frenzied mess, with the offense scrambling to the line of scrimmage and running whatever play it can get off. Meanwhile, Canadian teams get to set up and run a coherent final play. The American version feels like it should add more excitement, but really it just makes things messier. Canadian teams have a better shot of making something interesting happen.

• The Grey Cup features a halftime show, but instead of booking the hottest musical acts in the world, it gets the most Canadian musical acts. Last year Shania Twain opened her performance with a dogsled ride and a Mountie escort, and closed it by changing the final line of “Man! I Feel Like a Woman” to “I FEEL LIKE A CANADIAN!”

That was Shania’s second time doing the Grey Cup halftime show. Past performers include every hilariously Canadian act that you can think of: the Tragically Hip, Céline Dion, Bachman and Turner from Bachman-Turner Overdrive, and, of course, Nickelback. The 100th edition of the Grey Cup, in 2012, boasted an all-time lineup of Justin Bieber, Carly Rae Jepsen, and Gordon Lightfoot. (Sadly, the three artists did not share the stage.) So far as I can tell, the only prominent Canadian musicians who haven’t gotten the invite are Drake, the Barenaked Ladies, and Snow. This year’s performer is Alessia Cara, who I did not know was Canadian until exactly zero minutes ago.

It’s worth mentioning that the show does occasionally feature American acts. In 2014, Imagine Dragons performed at the Grey Cup, apparently due to an international statute that necessitates Imagine Dragons perform at all sporting events.

• The end zones in Canadian football are 20 yards long, and the uprights are positioned in the front of the end zone. This brings about a few differences in gameplay. First, red zone offenses tend to be more effective, since it’s harder for teams to defend such a large area of space. Getting into field goal range is also easier—the longest field goal in CFL history was a 62-yarder, meaning the line of scrimmage on that play was midfield. (Remember: the 55-yard line.)

And yes, this can happen:

• Canadian football includes something called the rouge, and we simply must talk about it. When a punt or missed field goal goes out of bounds in the end zone, the kicking team is awarded a single point. I love the rouge—and not just because it allows a team to literally punt for points. It also leads to unusual scores throughout games, which can lead to unusual decision-making. One thing I dislike about the NFL is that it deals almost exclusively in sevens and threes. Things get much funkier when coaches have to wrap their heads around unconventional scoring margins. Plus, games can end 17-1.

Best of all, the rouge led to the greatest play in sports history:

The Montreal Alouettes missed a potential game-winning field goal attempt in the waning seconds of 30-30 contest in 2010, but even after missing they were in position to score one point on a rouge. So the Toronto Argonauts fielded the ball and punted it out of their own end zone to prevent the game from ending 31-30. This sparked a punt off, resulting in the Als recovering a fumble, scoring a touchdown, and securing a dramatic victory.

• Receivers are permitted to get a running start toward the line of scrimmage in Canadian football, something that would draw a flag for a false start in American football. This rule facilitated the football highlight of the year:

(The other CFL highlight of the year: an offensive lineman legitimately chugging a beer after his team scored a touchdown.)

OK, now that we’re done sharing viral clips—and I gotta say, I’m proud of how many CFL clips I’m aware of—let’s focus on how this all fits together to create a distinct brand of football. Combine the ability of receivers to run toward the line of scrimmage with the fact offenses are allotted only three downs, and Canadian football becomes almost entirely about highly efficient passing.

After all, running the ball isn’t wise when the goal is to pick up 10 yards in only two downs. Two of nine CFL teams had players who registered more than 200 carries over the course of the 18-game 2018 season; meanwhile, 18 NFL players tallied 200 or more carries last fall. Four of the nine CFL teams had a 5,000-plus-yard passer this season, something that only five NFL players have done in the history of the league. And it’s not unusual for CFL quarterbacks to average 9-plus yards per pass attempt or have a completion percentage better than 70. Those figures would rank among the greatest NFL quarterback seasons of all time.

Americans generally believe that the CFL is some sort of minor league for the NFL. For example, we remember that Warren Moon and Doug Flutie got snubbed by the NFL, developed into stars up north, and then hit it big back in the States. But the CFL-to-NFL pipeline doesn’t flow as freely as some probably think. CFL teams don’t just sign the best players who can’t find spots on NFL rosters. They seek out players who will fit naturally into the Canadian game, and when those players find a niche up north, they tend to stay there, occasionally going on to become legends. The 2016 Grey Cup MVP was 41-year-old quarterback Henry Burris, who played a few games for the Bears in 2002 and then spent 13 seasons in Canada. The star of the 2017 Grey Cup was 38-year-old Ricky Ray, a third-stringer for the Jets in 2004 who became the only QB to win four Grey Cups as a starter. These players’ skill sets were suited to the Canadian game in ways that they weren’t suited to American ball, although it’s possible the Jets would have been better off starting Ricky Ray for the past 14 years.

I’ve come all this way without mentioning my favorite difference between the CFL and NFL. In Canada, the officials throw red (well, technically orange) flags when a foul has been committed, and the coaches throw yellow flags when they want to challenge a call. This is the inverse of the system in American football, where the officials’ flags are yellow and coaches’ challenge flags are red.

When I first picked up on this, I was floored. WHY? Why did Canada need to flip what America was doing on this extremely trivial detail? Were they just trying to be different?

But that isn’t the case. Over the years, I’ve realized my joke about Canada being a version of the U.S. that is 10 percent different is conceited. To most of the world, we’re the weird ones. We use Fahrenheit, two different types of ounces, and a medical system that causes people to go bankrupt if they get cancer. To Canadians, we decided to be 10 percent different.

Canada and America started playing football around the same time, in the 1860s. Originally, both forms of the sport allotted teams three downs per series and positioned the uprights in front of the goal line. You might watch the Grey Cup and assume that Canadians lopped off a down and moved the uprights to be edgy. But that isn’t what happened. We changed our game, and Canada’s version stayed the same. Some of the advances in both codes of football have been triggered by changes in the other, but for the most part American and Canadian football have been like Darwin’s finches, evolving into slightly different species to fit their environments.

There are parts of Canadian football I wish the U.S. game would consider. I love rouges, and the way that the Canadian clock functions at the end of the game. In Canada, pass-interference penalties are subject to video review—a system that seems much more logical than requiring officials to sprint downfield and make split-second judgment calls on whether contact on a 57-yard incompletion should lead to a 57-yard penalty. The CFL eliminated full-contact tackling in practices, which seems like an essential change if American football wants to continue to exist.

The NFL is the king of American sports leagues, and no upstart league will ever challenge for that title. That’s a real shame, because monopoly is the enemy of innovation. When all we watch is the NFL, we grow increasingly set in our belief that this is the only way football could look. So take in some fun-house mirror football this weekend. It’s important to remember that football (or anything in life) doesn’t have to be exactly the way it is now.