Writing and directing a based-on-truth sports flick can be a thankless job, given that sports fans are notoriously well-informed about history and notoriously picky when Hollywood messes with it.
"The last thing I wanted to do was make a kind of by-the-numbers, sappy sports movie," he said, "but early on I thought we should not forget what's great about the movies.
"What you really want is to feel like you're there with Robinson, and I think the best way to get that point across, whether you're black or white, you want to create a guy you relate to and want to go on a journey with."
The film does have its sappy moments -- several of them out of the mouth of Harrison Ford as Branch Rickey -- and presents an uncomplicated picture of a complex man. But the cast, led by Chadwick Boseman, is likable and believable.
It helped that Robinson's widow, Rachel, 90, worked closely with the filmmakers and has endorsed the finished product.
"Since the '70s, she's been optioning the life rights and it never got made, so the rights reverted back to her," the director said. "We had to convince her we were the guys to do it. She didn't want to get in the way of what we were doing, but she's been an adviser all the way through."
Helgeland said Ralph Branca, one of the few surviving members of the 1947 Dodgers, also was instrumental as a consultant.
With such guidance, Helgeland took as few storytelling liberties as possible, combing over old articles and boxscores, with help from the Baseball Hall of Fame. But sometimes events had to be compressed or words put into people's mouths.
"You try to limit it, but you always get slammed for inaccuracies because it only is from one side," he said. "When you're on our side looking the other way we have almost two-and-a-half years of a guy's life we're trying to tell in 120 minutes.
"Sometimes strict historical accuracy would result in a nine-hour-long movie, so you try to be true to the spirit of the events and have a greater overall truth."
As important as it was to tell the story accurately, so was capturing the look and feel of America and baseball in the mid-to-late 1940s.
"It's all in the details," Helgeland said, "so if the baseball doesn't look real, if the stadiums don't look real, then the stories won't look real."
Helgeland wished he had access to Tiger Stadium, which Billy Crystal used as a fill-in for Yankee Stadium in the 2001 movie "61*." But the old place was torn down several years ago, so he turned to ancient parks such as Rickwood Field in Birmingham, Ala., and Engel Stadium in Chattanooga, Tenn., which was repurposed as Ebbets Field.
The outfield walls and stands were generated by computers, using true dimensions of long-gone stadiums. On any given day about 150 extras in the stands magically were turned into thousands.
To get the baseball right, several actors had to be cut because of lack of athletic skill, and opposing teams' lineups were filled by former college players.
The production values are light years more advanced than in the 1950 version, "The Jackie Robinson Story," even though that film had one key advantage in the verisimilitude department: Robinson played himself.
"I liked it," Helgeland said of the original. "Obviously, he's not an actor, so it's fun to see him on the screen, but the odd thing is an actor could play him better than he could play himself."