400 Screens, 400 Blows is a weekly column that takes an in-depth look at the films playing below the radar, beneath the top ten, and on 400 screens or less.

Every year critics are subjected to who knows how many dozen documentaries; most probably don't bother to see them all, and others will be reluctant to admit that most of them are the same. Oh, the subjects are different. One may be about war in Asia and one will be about war in Europe and another is about politics in the U.S.A., but they're the same in structure and tone and rhythm. We usually get the big three: talking heads, stock footage and photographs, and sometimes some "re-creation footage."

Here are some pointers for future documentarians. 1) Don't do that thing where, if the subject starts crying, you discreetly keep the camera rolling, and then use that footage in the final film. If your cutting is otherwise neat and smooth during the rest of the film, then if you suddenly pause over a weeping shot for the first time, it's annoyingly obvious why you're doing it (see My Architect). 2) If the police or someone else tries to make you turn your camera off, pretend to comply and leave it on. It's very cool and it gets the audience on your side (see Street Fight). 3) No fancy graphics, unless your movie is funny (see Bigger, Stronger, Faster). Animation is still cool -- see Chicago 10 and Waltz with Bashir (208 screens) -- but it could get old, fast, so approach with caution.

Perhaps the most important thing to remember is that the great documentaries are about people. The more you can reveal about your subject the better the film is going to be. It's even better if your subject is nuts (see Gray Gardens, The King of Kong, Mr. Death, etc.). For my money, the best documentary yet made is Terry Zwigoff's Crumb, since Zwigoff had virtually unlimited access to the artist, his family, his past and his work; he knew what to shoot and when and how to put it all together. (Crumb may have been crazy, but Zwigoff dug down far enough to get both the cause and the cure.) This year's Oscar winner, Man on Wire (11 screens), was about one crazy mofo. The year's best documentary, Encounters at the End of the World, featured the uncensored explorations of another crazy guy, Werner Herzog.

If you only have one or two hours of camera time with your subject, you don't have a movie (see An Unreasonable Man). If you have an ensemble cast, rather than a single subject, you have a reality show (see Morning Light). If your movie is about "war" or "famine" or "credit trouble" or "flooding" and you don't have a main character, you don't have a movie. The reason Michael Moore has three of the top ten highest moneymakers is that he's in them, and he's interesting. He's funny and smart and bold as hell. It almost doesn't matter what the subjects are, or even if they're factual. Morgan Spurlock scored another one of the top ten docs (Super Size Me) with a similar approach. But make sure you have some camera presence before you try this yourself.

Of course, there are exceptions to every one of these rules. Two of the top ten documentaries feature birds on road trips (March of the Penguins and Winged Migration). I'm not sure what that means, but ultimately the final key to any great documentary is that you should be able to see it again. It's a work of art as well as a work of journalism, and its subject is more or less timeless. Films like Robert Flaherty's Nanook of the North (1922) and Frederick Wiseman's High School (1968) still have the power to affect us, mainly because of the people (or birds) involved both in front of and behind the camera; their emotions, not their opinions, still register.