That’s big talk, but this year’s compelling MLB World Series matchup tends to bring it out in people. It’s a rematch of the 2004 Fall Classic, in which the Red Sox won their first World Series in 86 years, and adds to a robust postseason rivalry between the two teams. The storylines are plenty: It’s a St. Louis squad of outstanding rookies facing a Boston team that only one year ago finished with an abysmal record amid negative press. (Fried chicken; beer; dugout; you remember.) It’s St. Louis barbecue vs. New England clam chowder. Budweiser vs. Sam Adams. Clean-cut rookies vs. bearded veterans.

Here at Fortune we’re interested in the business side of things and wondered: Which local businesses have some skin in the game? And could we get them to talk some smack or make a bold call? Anheuser-Busch was just one of many companies we tried that are based in St. Louis, with its old-guard business scene, and in Boston, a rapidly growing tech hub.

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Another tech company that has been in Boston since its inception in 2002 is online home goods seller Wayfair. Its cofounder and CEO Niraj Shah, No. 32 on this year’s 40 Under 40 list, grew up in Pittsfield, Mass., and has a home on Cape Cod. Shah says Wayfair has four season tickets to Fenway Park and for the playoffs the company runs an internal raffle, with winning employees getting seriously fired up.

Shah tells Fortune his own clearest Red Sox memory is from 2004, when he attended Game 4 of the ALCS with his Wayfair co-founder and Cornell pal Steve Conine. The Sox were down three games to none against the Yankees in a must-win situation, and fans will remember well what happened: The Sox won that game, won three more, and went on to sweep the Cardinals in the World Series.

That was an especially significant game for Shah, because his wife was pregnant at the time (she stayed home). “It was a chilly night, and the game went long; over five hours,” recalls Shah. After they got the win, “I remember the excitement in the city. It was unbelievable. The Red Sox went on to easily beat the Cardinals in four straight games. I hope the 2013 Cardinals will be just as easy.”

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They won’t be, if you ask a Cardinals fan. Shah predicts the Red Sox will win in five games, but David Farr, CEO of St. Louis-based Emerson Electric (EMR), thinks the Cardinals are a sure bet. “There is no town and no team like St. Louis and the Cardinals,” says Farr, who is captured behind home plate, arms up, in a St. Louis Post-Dispatch photo from NLCS Game 6. “I will be watching it all and cheering louder than anyone in hopes that we clobber the ball and the Sox and bring another Series home and add another World Series flag at the top of Busch Stadium.”

Meanwhile, communications firm FleishmanHillard’s offices in St. Louis and in Boston have turned the rivalry into a bet. Robert Dowling, president of the agency’s east region, and based in Boston, will have to deliver to Susan Veidt, president of the central region, a round of Sam Adams for the whole office if the Cardinals win; if it’s the Sox, Veidt will send toasted ravioli, a St. Louis staple, to the Boston offices.

Halligan, of HubSpot, is a bit more conservative with his prediction: He says the series will go all seven games, but perhaps that’s because he has tickets to Game 7 at Fenway if that scenario happens. Still, the company is taking no chances: Its CEO is a baseball stats geek who frequently references baseball in staff meetings, and during the 2009 season the company made employee shirts that recast HubSpot’s logo in the Red Sox font; staffers jokingly referred to themselves as HubSox Nation. “The complaint you hear about baseball as America’s pastime is that it can be boring,” says Halligan, “but this year’s team has been just the opposite. From the beards to hitting bombs and winning games in the ninth inning, it’s hard to argue with their success and grit.”

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One of the oldest and biggest employers in the St. Louis metro area is Anheuser-Busch (BUD). (See: “Brewmaster of the universe.”) And Busch is, after all, the name that graces the Cardinals’ home field. Jim Brickey, the company’s chief people officer, was born and raised in the city and remembers hiding under his covers and listening to the radio on headphones during late-night games. “My dad would take me to Cardinals games when I was a kid, and those memories are very special to me,” says Brickey. “In 1998, I took my dad to the last game of the season when Mark McGwire hit home run number 70. It was the last Cardinals game he was able to attend.” Brickey thinks that the Cardinals will be “looking to avenge the 2004 World Series” and will thus take it in six games.

At the St. Louis headquarters of agriculture giant Monsanto (MON), the food services staff donned Cardinals hats and jerseys today. Brett Begemann, COO, says “I’ll be at Monday night’s game at Busch Stadium. Even better is that on Saturday I’ll not only get the chance to cheer on the Cardinals, but also root on our 7-0 Missouri Tigers as they go for the win over South Carolina. There is no doubt it’s great to be a Missouri sports fan this October.” His call? Cardinals in six games.

Jack Dorsey, cofounder of Twitter and CEO of Square, may be based in San Francisco, but it’s no secret that he’s from St. Louis. He’s also notoriously press-shy; he declined to speak with Fortune about the series, but he has tweeted regularly about his Cardinals. “Cards go to the World Series!” he tweeted when his hometown team finished off the Dodgers. “4^th time in 10 years. Go STL @cardinals!” On August 28, one night before a Square “town hall” in St. Louis (attended by his parents), Dorsey brought some of his employees to a Cardinals vs. Cincinnati Reds game at Busch Stadium and tweeted a quirky photo of the field and his face hidden by a Cards hat. And although we couldn’t get him to talk any smack, we have a feeling that if his team does win, you might see some slightly more colorful tweets from the Square CEO.

Oh, and Tom Brady’s forecast? The New England Patriots QB — who has been involved with companies like Under Armour, Ugg, and Movado in the past — says Red Sox in five.