And what World Series teams they are.
Boston and St. Louis both finished the regular season with 97-65 records, and those marks were the best in each league. It's the first time since 1999 (Yankees and Braves) that this has happened, and the Sox and Cards will meet up in this year's Fall Classic starting Wednesday at 7:30 p.m. ET on FOX.
This is a baseball purist's dream series: two iconic Major League franchises in baseball-crazed cities with history galore, particularly when it comes to meeting each other on the Grand Old Game's grandest stage.
The Cardinals beat the Red Sox in the World Series in 1946 and '67. The Red Sox returned the favor with a sweep in 2004 that broke an 86-year "curse."
They're back at it in 2013, and it seems more appropriate than ever.
"If there's any way for a series to surpass what we just went through, we'll find out," Red Sox reliever Craig Breslow said while basking in the glow of TV cameras during the on-field celebration following their American League Championship Series win over the Tigers.
"At this point, any team that's still around is pretty good. They're riding high after a pretty dominant performance in the NLCS. We'll do our homework. We know we'll be prepared. Our coaching staff will give us all the information that's available, and the success will come down to executing the way we've done all season."
St. Louis will be bringing to Beantown a team that carries a potent mixture of offense, power arms, veteran experience and youth. The Cards beat the Pirates in an emotional five-game National League Division Series and prevailed in six against the Dodgers in the NLCS.
St. Louis got great starting pitching from ace Adam Wainwright, who will likely start Game 1 of the World Series, and unbelievable starting pitching from rookie Michael Wacha, who has not been beaten this October and who just defeated Clayton Kershaw in the NLCS clincher on Friday with shutout ball.
Since closing the regular season with 8 2/3 no-hit innings, the 22-year-old rookie has pitched 21 postseason innings, limiting the Pirates and Dodgers to one run on eight hits.
"I think we just don't talk about it much, because we don't want it to change," Cardinals manager Mike Matheny said of Wacha's brilliance. "We want to see it a few more times -- a couple, at least. We just want him to think that this is normal and this is expected."
What's also expected on the Cards' side is that Carlos Beltran, who has proven again this fall that he's one of the greatest postseason hitters in Major League history, will make the most of what somehow is his first trip to the World Series in 16 big league seasons. And that the selfless and talented group of players surrounding him in the lineup will contribute the way they have all year.
"During the regular season, we went through ups and downs and we stood together," Beltran said. "We did it as a team, actually. It was fun just being able to watch the veteran guys try to help the younger guys -- being able to see the younger guys coming along and just coming here and do their job. It feels great."
The Red Sox were echoing similar sentiments after polishing off the Tigers in the ALCS, which featured four one-run games out of the six.
In other words, the Red Sox are battle tested, too, and this pennant-winning club has a strong blend of character, grit and, most important, talent.
Boston rebounded from a last-place finish in the AL East in 2012 by rebuilding the roster through deft moves by general manager Ben Cherington, including the hiring of manager John Farrell. Starting pitchers Jon Lester and John Lackey were much improved, Clay Buchholz had an excellent year when healthy, and a makeshift bullpen molded by injuries to key pitchers somehow emerged as a force.
All the while, veterans like David Ortiz, Dustin Pedroia, Jacoby Ellsbury and Stephen Drew -- and new acquisitions Shane Victorino, Mike Napoli and Jonny Gomes, led the way with their bats, gloves and attitude.
"We've got to win four more games," Buchholz said. "But the way this team jelled and meshed right away in Spring Training, obviously every team in Major League Baseball has a goal to make the World Series and the playoffs from the start. Everybody here just believed it, and the numbers this year, they speak from themselves. The way guys grinded out at-bats throughout the season, passing the torch to the next guy -- it's what this team's about."
The Red Sox proved to be the most patient offense in the Majors this year. It will be tough to keep that up in a World Series in which they will encounter the proven effectiveness of Wainwright followed by the sheer stuff and poise of Wacha into more heat from St. Louis starters Joe Kelly, Lance Lynn and possibly Shelby Miller. And then there's the bullpen, where closer Trevor Rosenthal, lefty Kevin Siegrist and righty Carlos Martinez all bring mid- to upper-90s gas.
Then again, Boston has one of the best closers in baseball in Koji Uehara, who continued his astounding season with an ALCS MVP Award-winning performance. Farrell will not hesitate to use Uehara for multiple innings, and his setup men -- righty Junichi Tazawa and lefty Breslow -- were seamless in getting the ball to him against Detroit.
So what will it be?
With two teams this good and apparently evenly matched, the only answer we can be confident about might be: "Incredible baseball."
It is the World Series, after all, and Boston catcher Jarrod Saltalamacchia's words after his team punched its ticket captured what both clubs are surely thinking.
"We're not going to stop," he said. "We know what our goal is. We want to win the World Series. We're going to bust our tail and make it happen."