Casting in fiction filmmaking is often said to make or break a film.  But this is even more the case in documentary, where casting often involves making a bet that the subjects’ lives will make for an entertaining story.

Director Marshall Curry certainly bet well when casting three tween race kart drivers for his latest doc, Racing Dreams, which picked up the award for Best Documentary at Tribeca and screened this past week at Silverdocs.   Annabeth (11), Josh (12) and Brandon (13) “popped out” in screen testing, said Curry, who sensitively documented  their earnest, sometimes sad, and often humorous childhood travails all the while competing in the year-long World Karting Association Championship.

Curry last swept the festival circuit with his first documentary, Street Fight, which picked up an Oscar nomination in 2005.  His latest features sharper production values but no less compassion.

I was able to meet up with Curry after his screening at the AFI Theater in Silver Spring on Saturday. Here’s what he had to say:

Q: How did you select the characters for the film?

I read an article about the World Karting Association and found it to be interesting and thought, well I’ll go and see it. So I took a camera and went to a couple of races and just started asking people: “who do you think I should talk to?”  A couple of people said you should really talk to Josh Hobson.  So we went to the Grand National Race a year before we started shooting and I finally found Josh as he was pulling off the track and he had just won his fourth Grand National Race over the weekend.  I talked to him for twenty minutes and I just thought, wow, if there are other kids out there like this, then we have one hell of a movie. And so I took the footage home and I edited a trailer and showed it to Bristol Baughn, who was working at one of the finance companies for the project.  She saw it and said, great, let’s do it. So we went to that year’s karting convention award ceremony and just started fanning out and talking to about 75 kids.  There we met Annabeth and Brandon.  We met a lot of kids there that we really really liked, but those three kinda popped out. So we took a chance with those three, and all three turned out to be great.

Q. Would you consider documenting these kids again, say, five years down the road?

One of the things that attracted me so much to this age was that its such a pivotal age and its an age that a lot of people really don’t pay that much attention to.  Amazingly, you see Annabeth at the beginning of the movie and at the end of the movie and in one year she’s a young woman. I’m sure we will do a short followup as a DVD extra or something like that.

Q. How did you achieve such a level of intimacy with your characters?

Intimacy is something that is super super important to me. We really wanted to shoot the movie HI Def, with great cameras and give that sense of pageantry of racing.   But at the same time I didn’t want to roll in there with the big camera and the lights because I just know how that freezes people up. And to me, I would always prefer and intimate slightly less high production value scene than a slick hollow moment.

Q. How was making your second film different than making your first?

My first film was really film school for me. I had never shot or edited before so it was an incredibly slow long process for me.  I basically read the manual of the camera before I went on my first shoot and shot you know, 200 hours and the first 50 are lot worse than the last 50.  And then editing took me two years.  I edited everything myself, logged everything myself, transcribed everything myself.  There were no interns or anything like that. This time we had really good shooters that were working with us and I had another editor I worked with full time and another editor we brought in three quarters of the way through. So definitely that made it a lot easier. But it was also a challenge because with Street Fight, if I saw something that I thought we should be shooting, I would get it. And when somebody else is holding the camera it is harder to do that.  But then again, I’m working with people who have been shooting for 20 years and they are never having to find the aperture on the camera in an important moment.

Q. Were there any ethical dilemmas that you faced, especially with the more sensitive elements of some of the characters’ lives?

There’s nothing worse than pointing a camera at a person in a painful situation and treating them like a subject, when all you really want to do is put the camera down and hug them. That’s the part of my job that I hate the most – to see somebody you care about suffering and to be thinking about whether you’ve got it in focus. But I also know that if you want to make movies, that’s what you’ve got to do. So I would talk to them beforehand and say: during the course of this movie, there are going to be some uncomfortable times and your kid is going to lose a race and be crying and I’m going to shoot it. And its not that I’m a vulture, but that’s part of the story, and I feel like they all pretty much understood that. After we screened the film to the families, Brandon’s grandmother turned to me – and she’d been crying throughout the movie – and she she said: It’s really hard to watch and its completely true and I wouldn’t change a thing. And I think that they realized the value of telling their story.

Q. Why documentary?

I guess I’m just curious about things and it gives you an opportunity to go around and poke in other people’s lives. I like just the craft of it too. I like just the serendipity of it. You’d shoot a fiction film, and everything was put there. And then you shoot a documentary, and all of a sudden the kid picks up the phone and starts calling and this whole thing happens and you’re like, gee, I hope the battery doesn’t run out. And I’m not a fisherman or a hunter, but I’d imagine its similar to that. You go out and you spend all day on the water and somedays you don’t catch anything.  But once in a while, you get a big one and it’s so thrilling.

Q. What are you working on next?

I have a film that I’ve shot and I’m going to start editing that is about a radical environmentalist who burned a couple of timber facilities in Oregon and is now in prison.