By Aly Semigran
Updated August 31, 2011 at 02:15 PM EDT

As any fan of the long-rivaled Boston Red Sox and New York Yankees can attest, those New Era commercials that pit John Krasinski (the Sox purist) and Alec Baldwin (the Yankees diehard) against one another perfectly encapsulate the trash-talking banter and deep-seated contempt that the followers, even friendly ones, of the two teams feel towards one another. In fact, Bryan Buckley, the director behind those ingenious ads, sees the spots as almost a metaphor for the generations-spanning rivalry. “It’s always been interesting to me that [the commercials] are in black and white,” he tells EW. “Because that’s exactly what the rivalry is: Black and white. You either go one way or the other: Red Sox or Yankees.”

While Krasinski and Baldwin both stand strong on which side of the battle line they fall on, the actors (and real-life friends) were more than happy to step up to the plate and work together once more (they first collaborated on the 2010 comedy It’s Complicated) to represent their respective teams. Buckley, who has worked on other memorable promos over the past few years, including the oft-repeated “What Happens in Vegas” campaign, spoke with EW about how the wildly popular New Era ads featuring the two stars came to be and why its struck such a chord with baseball fans… and even some of the players!

The initial idea for the campaign, as Buckley explained, was the brainchild of advertising agency Brooklyn Brothers and their creative director Guy Barnett. While they knew right off the bat that the commercials would feature two dueling celebrities who were “real fans of the game,” the big question was who would those stars be. After Buckley, a Sox fan himself, was brought on board to direct, he knew Krasinski, a fellow Massachusetts native, was the right one to rep for their team. Once they got the thumbs up from Krasinski, The Office star recruited his pal and sports foe, 30 Rock‘s Baldwin, to play nice(-ish) against him in the ads.

After a meeting with Buckley and the creative team behind the campaign, Krasinski, along with The Office scribe Charlie Grandy, took a few weeks to morph the general idea into fleshed-out scripts for the commercials. “John really personalized the scripts,” Buckley says. “The minute you read them, it was like, ‘Oh my God, these things are so funny.'”

With the go-ahead from New Era (“Those guys really let [Krasinski and Grandy] do their thing”), Krasinski and Baldwin shot the series of promos on a shoestring budget over the course of two days in two different New York City brownstones (neither of which belong to Krasinski and Baldwin, for the record). While the actors didn’t stray too far from the scripts, they certainly tapped into their own experiences. “John told me they actually do text each other and ride each other about their teams,” Buckley says.

Of course, just like the ads themselves, it was all in good fun, and really, a tribute to the game itself. “There’s so much passion about that rivalry,” says Buckley, “they wanted to do it for the love of their teams.” The mixture of Krasinski’s willingness to put up with a lot for the sake of his beloved Beantown ball club (in the ads, he’s been tricked, assaulted, and photoshopped for the Yankees JumboTron), and Baldwin’s famously intimidating 30 Rock-like demeanor (as Buckley puts it, “You’re already in trouble facing off against Baldwin, but then you’re arming him with searing humor”), has struck a chord with just about everyone. In fact, Buckley heard through the grapevine, “Derek Jeter really liked the campaign.” (Score one for Team Baldwin!)

While the Sox-Yankees war seemingly has no end in sight, unfortunately the commercials might — at least for now, anyway. Buckley told EW that the final ad of the series, which will pick up where the last one left off (with a newly-homeless Baldwin taking up residence with Krasinski, after burning his apartment, and some Red Sox tickets, to a crisp), will likely air right before the intensely heated post-season starts. “You couldn’t have picked a better season for these commercials to air,” Buckley says, referring to the Sox and Yankees’ neck and neck battle for first place in the American League East. “We had so much fun doing these and I could see there potentially being more of these ads…. Neither of the guys said they wouldn’t come back, [but] don’t count on there being more right away.”

Still, Buckley promises the final Krasinski-Baldwin showdown won’t be a disappointment. “It’s a great finale,” he teased, adding, “It ends in a very unexpected place.” So once again, come September, Sox and Yanks fans will be left pondering where that place will be: Fenway or Yankee Stadium? As Buckley put it, in the spirit of the good sportsmanship, “May the best man — and team — win.”

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