Jeremy Hobson: Well now to New York, where the TV networks are unveiling their fall schedules to advertisers this week at an event called the upfronts.

As Marketplace's Adriene Hill reports, some of the biggest suspense isn't about what shows will be on -- but when.

Adriene Hill: The upfronts are about selling ads, sure. But they're also a chance for the networks to reveal the lineup -- which shows are in, on their way in and out.

Brad Adgate: These are like gametime decisions, to coin a sports phrase.

Brad Adgate is an analyst at Horizon Media. Scheduling the networks lineup, he says, is tricky: You want your hit comedy leading into your new comedy. And you don't want your police procedural going up against "CSI."

Adgate: It's almost like putting together a jigsaw puzzle.

DVRs and 0n Demand are changing how these pieces fit together. But they still matter.

Joe Adalian from Vulture.com calls TV scheduling a "scientific art."

Joe Adalian: Those of it who cover TV like to think of it as more of an art, because we like to think that there are these brave scheduling jockeys who are trusting their gut working on instinct.

But he says, there's a whole lot of research that goes on behind the scenes, with input from the network's sales department.

I'm Adriene Hill for Marketplace.