Baseball may be the national pastime, but baseball movies generally don't do very well at the box office. Neither do movies with unknown stars, or thoughtful historical dramas for grown-ups (at least, not in April), or, for that matter, movies featuring Harrison Ford (at least, not lately). The new Jackie Robinson biopic "42" is all of these things, and yet it outperformed expectations in its chart-topping theatrical debut this weekend.

The film had been expected to earn no more than $20 million in its first three days. In fact, it earned an estimated $27.3 million, the biggest debut ever for a baseball movie. (The previous record-holder was sports comedy "The Benchwarmers," which opened with $19.7 million in 2006.) As a result, previously unknown Chadwick Boseman, who plays the hall-of-famer, suddenly looks like an overnight star.

How did "42" manage to hit it out of the park? Here's what it did right:

Broad Appeal: "42" seemed to offer something for everyone. The story of how Robinson broke the color line in major league baseball was expected to draw African-American audiences, but Robinson's heroism so transcended civil rights activism and sports that it should also have held appeal for people of all backgrounds. As a historical drama set in the 1940s, it would appeal to older audiences, but the sports action and continuing relevance of Robinson's achievements gave the movie appeal beyond the nostalgic or educational. And even though it was a sports movie, it played surprisingly well among women (who made up 52 percent of the audience, according to distributor Warner Bros.), perhaps because the movie also gave emphasis to Jackie's romance with wife-to-be Rachel (Nicole Beharie).

Good Reviews: Most critics liked the film, finding it uplifting even though it offered few surprises or character quirks in its straightforward, warts-free portrait of the Brooklyn Dodger. To the older audience that was the primary target for "42," good reviews still matter.

Strong Word-of-Mouth: Unlike critics, audiences don't mind being manipulated and having their buttons pushed. For many filmgoers, that's why they go to the movies in the first place. "42" pushed all the right audience-response buttons, and as a result, the film earned a rare A+ rating from CinemaScore. Viewers who saw it on Friday were especially eager to recommend it to others over the rest of the weekend.

Good Timing: Warner Bros. was smart to release the movie as baseball season opened, and close to Jackie Robinson Day (April 15, the 66th anniversary of his debut with the Dodgers). But the studio was also smart to release it in April, when grown-ups are starved for quality mainstream movies, when the only real competition is playing in limited release in the art-houses, and when summer blockbusters are still a few weeks out from stealing thunder away from smaller movies like this modest ($40 million) production.

Stellar Marketing: At 70, Harrison Ford is far from the box office draw he once was, but the often taciturn star was unusually enthusiastic about promoting his supporting role in "42" (he plays Branch Rickey, the Dodgers general manager who makes history by hiring Robinson). He was on seemingly every talk show, appearing not just chatty but even moved by the poignant place Robinson's story holds in American history. Having Ford make the rounds surely helped attract older audiences, but Warners cleverly attracted younger ones, too, by using in its marketing the anthem "Brooklyn (We Go Hard)" by Jay-Z. The effect was to make the movie seem contemporary, relevant, and anything but nostalgic by connecting the original Brooklyn sports hero with the modern-day entertainment mogul who helped bring big-league sports back to Brooklyn (basketball's Nets) for the first time in the more than 50 years since the Dodgers vacated the borough for Los Angeles.

The Right Brand: "42" is just the latest example of a big-studio production whose familiar brand is such a strong selling point that even an unknown can play the lead. In this case, the pre-sold brand was Jackie Robinson; he, not Boseman, was the real star of this film. Usually, that notion applies to big-budget special effects blockbusters based on comic-book superheroes. But Robinson was a real-life superhero to many in the 1940s and '50s and remains so today. He was bigger than baseball. This weekend, more than 40 years after his death, he proved he was bigger than movies, too.

EARLIER: '42' Review: 10 Things You Should Know
CATEGORIES Movies