In Medias Res…ish
Quick Latin lesson (because we're all about the edumacation): in medias res means "in the middle of the action."
We say "in medias res ish" because the film kind of has two beginnings. First, the film throws us into the middle of a conversation at a diner where the men are having some breakfast. This scene begins without an introduction, literally starting before we actually see anything, when the screen's still black. The scene itself serves to introduce the rest of the movie, but it's hard to know that on a first watch. In fact, after completing the movie for the first time you may have completely forgotten the diner scene, as it really plays no significant role in the plot. It may occur at the beginning… but that doesn't mean it provides traditional exposition.
When the movie's main action starts, it also begins before we actually see anything. The screen's still black and we begin to hear the desperate voice of the bleeding Mr. Orange. Suddenly, we're in a very bloodstained car with two men, one of whom has been shot. They drive to a building (which turns out to be a funeral home), and from there, what's actually happened slowly begins to unfold. This seems to be the true beginning of the film; the first scene acts as a sort of preemptive flashback, before we even know what kind of narrative we're in for.
Flashbacks; there are a lot of those. They give us some characterization and help reveal the plot. The flashbacks change the movie from a bunch of criminals arguing in a funeral home to a heist film (minus the heist) with a mystery twist as we try to piece together what has happened and how we ended up where we started.
The film is nonlinear in its narrative technique, but there's a general consensus that the flashbacks don't make things too confusing. Instead, they give us the perspectives of many different participants in the heists, giving the film a kind of Rashomon quality. We don't get different first-person perspectives, but we see the events experienced by the different gangsters. Each guy's story adds to the narrative and Tarantino pulls it all awesomely together in the end.
Rather than the non-chronological structure making the audience confused, Tarantino thought it just made them curious. He didn't like to call the different perspectives "flashbacks." He saw the narrative style as like a novel, where a story might be interrupted to tell you more about what's going on with one of the characters. He thought that this narrative style added to the suspense:
TARANTINO: It's not a flashback. Novels go back and forth all the time. […] Flashbacks, as far as I'm concerned, come from a personal perspective. These aren't, they're coming from a narrative perspective. They're going back and forth like chapters. I like the revealing of information and deciding what I'm gonna reveal and when I'm gonna reveal it […]Part of the excitement of the movie comes from the fact that you don't quite know what happened, it's just everyone's interpretation.
Hmm. Still kind of sounds like a flashback… but we'll let Tarantino hold the mic on this one.