When discussing his series, "Cops" mastermind John Langley can't help mentioning a few of its 700-plus episodes.

Like the one where an overweight woman lunged at an officer with a butcher knife.

"She falls down and the knife goes all the way in her gut! I mean, to the hilt! And she lived!" He's clearly still amazed.

"And then we had the naked burglar in Philadelphia. The cops answer the call, and the guy's on PCP, which for some reason makes people take their clothes off. It takes about seven cops to subdue him.

"Then, a year or two later in Pittsburgh, the same thing: a naked burglar coming out of a school." Langley chuckles. "Ver-r-ry bizarre."

Not every episode of "Cops" is ver-r-ry bizarre. Even so, the prospect of seeing something unexpected, unhinged or simply true-to-life has kept viewers — more than 6 million on average last season — tuning to "Cops" each Saturday since March 1989.

But you don't have to watch "Cops" to have felt its cultural impact. Countless scripted and reality series have borrowed its "video verite" storytelling style.

Meanwhile, it inspired the Comedy Central spoof "Reno 911," and its reggae-flavored theme song ("Bad boys, bad boys") was memorably borrowed by "The Simpsons": "Bad cops, bad cops! Springfield cops are on the take. But what do you expect for the money we make?"

"Cops" is an institution, however unlikely. And lodged off the beaten path on TV's least-watched night. Which suits Langley fine.

"Each new Fox exec comes in and has a lot of other issues to take care of every other night," Langley says. "Then he gets to Saturday and goes, 'Oh, we got "Cops," let's just leave that alone.' So we're very happy, just plugging along."

Come fall, "Cops" will be plugging along for its 20th season, its nimble camera crews (10 of them) continuing to patrol the nation gathering 400 hours of footage per week to whittle into each episode.

When "Cops" premiered on the struggling new network, it made a splash.

"It had a big 'wow factor,' " Langley recalls. " 'Documentary in extremis' ... 'existential variety show' ... things that people weren't used to seeing."

Nowadays, "Cops" sticks to an unyielding format. Each half-hour comprises an action segment, then a slow-things-down segment, then a leave-the-viewer-with-a-message segment.

For instance: In one recent episode, a cop in Boston gave chase to a youth with a gun. Then Las Vegas cops patiently defused a domestic dispute. And finally in Boise, Idaho, a cop displayed remarkable compassion for a pair of troubled women (with a reminder to all: Stay off crack).

This all suggests that "Cops" isn't so much about crime as about everyday people who get themselves jammed up with society and each other — and how the cops who encounter them try to sort it out. John Langley's idea has worked for almost two decades. People being people, "Cops" just might last forever.