NEWTON, Mass. – Turreted and stately, the house on a quiet street in Newton had been vacant for a while.

But for a few days last month, its “For Sale” signs went away. Trucks, trailers, crews and actors converged along Lake Avenue after fliers in every neighbor’s mailbox gave fair warning: This picture-perfect homestead would temporarily be occupied as one of several shooting sites around the Boston area for a CBS pilot called “Quinn-Tuplets.”

This wannabe series features Amber Tamblyn, Kenneth Mitchell, Sam Witwer, David Giuntoli and Anna Chlumsky as all-grown-up quintuplets named Quinn.

But further details weren’t available, or worth a viewer getting too excited about, yet. “Quinn-Tuplets” may never make it to the air.

“Quinn-Tuplets” is just one of 80-plus scripted pilots in production and due to be evaluated soon by the five broadcast networks. Each is bucking for a berth on a fall prime-time schedule. But only a handful will make the cut.

That means if “Quinn-Tuplets” doesn’t pass muster with CBS execs, it will be tossed, forever unseen by the public, on the lofty scrapheap of busted TV pilots.

Such is the game of win or lose played out each pilot season in a high-stakes, time-crunched scramble.

Lately, a year-round program rollout has found favor in the industry. Even so, the May “upfront” presentations — heralding a new crop of fall TV to advertisers and the world — remain. This half-century-old rite perpetuates the need for pilots to sustain it. Lots of pilots. Pronto.

Shawn Ryan, with series to his credit including “The Unit” and “The Shield,” has a pilot in the works for Fox called “Ride-Along.”

“When you’re producing an ongoing show,” he said one hectic day last week, “it feels like you’re in an out-of-control car hurtling 100 miles per hour and you never know whether you’ll get someplace, or crash. With a pilot, you start at a standstill, and you’re told you’ve got to be at 100 miles per hour — tomorrow!”

Almost in lockstep, the process goes like this: Come January, scripts for dramas and comedies are picked by the studios from hundreds in development. Production begins. the end of April, each finished pilot is delivered to the network that ordered it. Then, in mid-May, the networks unveil their fall lineups, with a lucky few new shows part of the mix — all whipped together in a frantic fortnight.

Stapf has a dozen pilots under way for the sister CBS network (besides “Quinn-Tuplets,” they include a revived “Hawaii Five-O” and “Reagan’s Law,” a cop drama starring Tom Selleck), plus two for the CW. These came from scores of scripts and series pitches he’d been shepherding since last summer.

But for Cindy Chupack, the script development phase of her NBC project, “Love Bites,” took place two years ago. Then NBC opted not to go the next step to a pilot. Much to her surprise early this year, Chupack learned “Love Bites” had sprung back to life: The network’s current bosses wanted a pilot. Under the aegis of NBC’s Universal Media Studios, she started hiring a crew and casting roles.

Chupack (whose credits as a writer-producer include “Sex and the City”) conceived “Love Bites” as an hourlong romantic comedy anthology with loosely connected tales of love, marriage and dating. Besides a slate of guest stars, she signed Becki Newton (“Ugly Betty”) and Jordana Spiro (“My Boys”) as the series’ regular cast members.

“We’re going from words on paper that only a few executives saw and decided not to make before, to now,” said Chupack before the 14th and final shooting day. “It’s really nice to employ a lot of people and have them making this thing that’s been on paper for a long time.”