We are exactly 12 days away from Game 1 of the 2018 World Series, and we know the matchup will be one of four possibilities: Brewers-Red Sox, Dodgers-Astros, Brewers-Astros or Dodgers-Red Sox. Each of these matchups will be fun -- it's the Fall Classic, after all -- but some of them are fascinating beyond the conventional matchup. Here's a look at three potentially enjoyable aspects of each of the four possible World Series combinations.
BREWERS-ASTROS
1. You're going to keep forgetting which team is in which league.
The Brewers made the World Series in 1982 as an American League team, but this year, they'd be there as a National League team for the first time. The Astros made it in 2005 as an NL team, but they'd be back for the second year in a row as an AL team. Theoretically, in any year between '69 and '97, these two teams could have played in the Fall Classic as representatives from the opposite leagues they are representing right now.
2. They even used to be in the same division.
From 1998 (the year the Brewers moved to the NL) to 2012 (the Astros' final season in the NL), Milwaukee and Houston were in fact NL Central rivals. The Astros won two division titles in that time ('98, '99) and the Brewers won one ('11). The early-aughts version of yourself is so, so confused by this World Series.

3. Josh Hader haunts his old mates.
Well, sort of. Hader made his MLB debut last season, and he's been dominating hitters ever since. But back in 2015, when he was a 21-year-old starter, the Astros traded him -- along with Domingo Santana, Brett Phillips and Adrian Houser -- for Mike Fiers and Carlos Gomez. Fiers is now with the A's and Gomez is with the Rays, but Hader is burning it up in Milwaukee and would surely cherish doing so against Houston in the World Series.
BREWERS-RED SOX
1. Milwaukee took away a Boston team once.
It might seem strange now that a team would leave the city of Boston for Milwaukee, but that's what happened in 1952, when the Boston Braves moved to Milwaukee. The Brewers, at the time, were the Braves' farm team. The move actually happened at the very last minute: The sale of the Braves was announced on March 18, and the team moved to Milwaukee immediately. The Braves, of course, moved to Atlanta in 1966, and the Milwaukee Brewers, named after Boston's old farm team, came along in 1970, when the Seattle Pilots moved to Wisconsin.

2. Welcome back, Travis Shaw.
Do you remember why the Red Sox traded Shaw? Because they were hoping Pablo Sandoval could take over third base. He was Boston's opening day starter in 2017, and he was released three months later. Meanwhile, Shaw has raked ever since arriving in Wisconsin, hitting 31 homers last year and 32 this year.
3. Tom Brady might not be cheering for the Red Sox.
Seriously. In an interview with Westwood One last week, Brady said that he has become a Brewers fan, thanks to a close friendship with Milwaukee owner Mark Attanasio. If Brady thought his brief foray into electoral politics was a public-relations headache for him, try rooting against the Red Sox in the World Series.
DODGERS-ASTROS
1. Rematch!
Considering how much fun last year's was, who would be against another one? This would be the first World Series rematch, as MLB.com's David Adler noted, in exactly 40 years, since the Yankees and Dodgers met in the 1978 World Series. (New York won in '77 and '78.)

2. They used to be bitter rivals.
As Joe Posnanski pointed out last year, the Astros and Dodgers had some intense postseason battles in 1980 and '81, with Houston winning a tiebreaker game in '80 and the Dodgers winning a pseudo-NLDS (because of the strike) the following season. The Astros being in the NL basically made them rivals with every team at some point.
3. They still won't play the craziest game the two franchises have ever played.
Did you think Game 5 last year was the nuttiest game between the Astros and the Dodgers? They'll never top the 22-inning marathon from 1989, which ended at 2:29 a.m. CT before an afternoon game the next day that went 13 innings. Houston and Los Angeles still have to be sick of each other after that game.
DODGERS-RED SOX
1. Those stadiums.
Nothing against Minute Maid Park and Miller Park, but a Fall Classic with Fenway Park and Dodger Stadium as the backdrops? These are two of the three oldest stadiums in the sport -- Fenway opened in 1912 and Dodger Stadium in '62 -- and they've been the site of too many iconic baseball moments to count. Everything looks gorgeous at these stadiums.
2. Still, the crowds will feel small … relatively speaking.
Trivia question! What's the greatest number of people to have ever attended a baseball game? The number is 115,301, to watch a Spring Training game between the Red Sox and the Dodgers at Los Angeles Coliseum in 2008. That's the only thing that could make a World Series crowd feel paltry.

3. That crazy 2012 swap.
The wildest trade in baseball memory happened in 2012, when the Red Sox shipped Carl Crawford, Adrian Gonzalez and Josh Beckett -- and their massive salaries -- to the Dodgers for … well, does it really matter? Los Angeles took on roughly $250 million in salaries, and then-new owner Magic Johnson said it was because "we want to win now." The Dodgers didn't win the NL West that year, but they have every year since, though those players didn't have much to do it. Funny thing about that massive nine-player trade? None of the players are in the Majors anymore.