Paul Reiser got NBC’s attention when he walked into the network earlier this year with multiple scripts completed for a comedy series in which he plays himself, more or less.

Matthew Perry set up a deal at ABC for his return to sitcom-dom only after he and producer Jamie Tarses had hand-picked the scribes to flesh out his idea and enlisted Thomas Schlamme to direct and exec produce the pilot.

Both are bellwethers of a TV pilot season this year in which some of the hottest properties have taken a roundabout route to the network runway. What were once rare exceptions in a tradition-bound process are fast becoming a preferred way of navigating pilot season, particularly for talent with clout.

The networks are increasingly warming up to projects that come in the door much more fully formed than in the traditional process by which writers pitch concepts to network buyers and hope to land a script order. Spec pilot sales are becoming more commonplace, as are projects that are pitched out detailed over 13-episode arcs with the goal of securing more than just a pilot order.

The openness to variations on the usual themes comes as network and studio execs are under pressure to find more effective ways to deploy the $40 million-$60 million or so that each of the Big Four spend annually on pilots. That’s also why more and more projects that may not have gone the distance during one development season are getting second looks a year or two down the road.

“You’re automatically going to get more attention when you come in with a package or a (completed) script,” says a lit agent who guided a scribe client through a non-traditional sale this year.

Prominent scribes are increasingly writing pilot scripts on spec and shopping the completed scripts to buyers, who are afforded a much deeper understanding of a writer’s vision for a project. Many writers prefer the spec process because those scripts tend to go through less of a gauntlet of exec notes and rewrites. A completed script allows buyers to say yea or nay in a more definitive fashion.

Top-tier writers have been successful in staging auctions for spec scripts that have drawn frenzied bidding from nets. J.J. Abrams did so late last summer with “Undercovers,” the spy-fy dramedy he penned with Josh Reims that landed at NBC. NBC swooped in on the David E. Kelley spec for legal ensembler “Kindreds” that went on the block late last year. Abrams did the same thing two years ago after he and Alex Kurtzman and Roberto Orci wrote the pilot that became Fox’s “Fringe.”

Reiser had struck out in recent years in fielding comedy pilots for CBS and NBC. This time around, the multihyphenate is said to have taken his time on a project that was near and dear to his heart — he plays a man of a certain age who’s trying to balance the next phase of his life as a husband, father and friend to his close circle of guy pals. With scripts in hand, Reiser set “Next” at Warner Bros. TV — even though it emerged late in the development cycle in January — and quickly sold the package to NBC, complete with seasoned showrunner Jonathan Shapiro on board.

“Friends” alum Perry had a brainstorm for a laffer about a guy who manages an aging sports arena in San Diego and decides to re-evaluate his life after he hits 40. Perry linked with Tarses, who championed “Friends” during her days as an NBC creative exec, and brought in scribes Alex Barnow and Mark Firek to flesh out the script for “Mr. Sunshine” through Tarses’ Sony Pictures TV-based production shingle. Once Schlamme (who worked with Perry on NBC’s “Studio 60 on the Sunset Strip”) was onboard as director/exec producer, NBC and ABC got into a bidding skirmish to land the project when it was shopped in October.

But it’s not just boldface names in on the action.

“Traffic Light,” the most buzzed-about comedy prospect at Fox, was a spec fielded by sitcom vet Bob Fisher. NBC was drawn into conspiracy thriller “The Event” on the strength of scribe Nick Wauters’ spec. CBS picked up “Open Books,” a laffer set in the publishing world, after outbidding other nets for the script fielded by “Will and Grace” alumnus Gail Lerner.

The heat in the pilot spec market was kindled by the success of “Desperate Housewives.” The sudser that helped revive ABC’s fortunes was born of a spec by Marc Cherry, who was anything but a hot writer at the time the script was shopped. (In fact, the script was famously rejected all over town until ABC bit in 2004.)

The changing landscape for pilot deals reflects the urgency to reinvent the business model for scripted primetime programming. (Not a week goes by these days without a net or studio mogul lamenting the “broken” economics of the primetime biz at an industry confab.) With auds splintering and in-season reruns a thing of the past, net execs are grappling with the harsh reality that they can’t spend like they used to on pilot R&D, or on the shows that make it to air.

You know things are changing when one of CBS’ most promising comedy prospects is a spinoff from a Twitter feed: the William Shatner starrer “S**t My Dad Says,” from youthful scribe Justin Halpern.

Fox Entertainment chairman Peter Rice and prexy Kevin Reilly have been adventurous during the past year with their development.

Matt Nix, creator and exec producer of USA’s top-rated actioner “Burn Notice,” garnered a 13-episode order for the buddy cop actioner “The Good Guys” after he presented a detailed blueprint for a show to be done on a budget closer to the cable standard rather than the $2.5 million-$3 million per-episode norm for network primetime these days. (For starters, the show lenses in the Dallas area.)

“Good Guys” producer Fox Television Studios, also home to “Burn Notice,” has been innovative in cobbling together financing from various sources for shows that are pitched to network buyers as 13-episode packages, not the traditional sweat-out-a-pilot process.

The idea for the show stemmed from a feature spec that Nix wrote years ago. It wasn’t hard to adapt into a weekly series with close-ended storytelling and action elements that would appeal to international buyers, Nix says.

“Good Guys,” starring Bradley Whitford and Colin Hanks, will be sneaked May 19 in the 8 p.m. hour leading into “American Idol” before settling in the Monday 9 p.m. berth on June 7. Fox execs have taken pains to assure that the summer skedding is part of the network’s efforts to seed scripted projects during the summer months — and not a sign that the net is treating it as a burnoff run.

“Part of what was appealing (to Fox) was that this was a more manageable way for them to do more year-round programming,” Nix says.

The certainty of knowing the project would have a 13-episode order was nice, but there were some drawbacks, too, Nix says. On the traditional timetable, showrunners have plenty of time to tweak a pilot and think about where the series is headed in the months between the time the pilot is shot and the series goes on the air.

In the case of “Good Guys,” Nix notes, “We were shooting episode two the day after we finished episode one. We had to find our feet more quickly than shows typically do.”

Another Fox project eying the straight-to-episodes route is the ambitious “Terra Nova,” a drama about a family from 100 years in the future that winds up back in prehistoric times battling dinosaurs and the like. The spark of the idea came from British scribe Kelly Marcel, who was paired with drama writer Craig Silverstein to work out a script that drew bids from CBS as well as Fox when it was shopped last summer.

After the idea piqued Rice’s interest, he helped recruit heavyweights Steven Spielberg and Peter Chernin as exec producers. “Terra Nova” is now seen as a likely to eschew a single pilot in favor of a 13-episode order (probably for midseason) once the casting process is complete. With the elaborate sets and special effects the project demands, it makes more financial sense for Fox and its 20th Century Fox TV sibling to go all-in for 13 segs in order to better amortize the startup costs.

The other clear trend on the pilot front is redevelopment of projects. NBC has high hopes for the romantic dramedy anthology pilot “Love Bites,” from “Sex and the City” alum Cindy Chupack. The project was first developed at the Peacock for the 2008-09 season. It was revived last year with Chupack and a new set of producers, the Working Title team of Timothy Bevan, Eric Fellner and Shelley McCrory (it marks the Brit production shingle’s first U.S. TV project.)

Another NBC project, domestic comedy “This Little Piggy,” had its first go-round last year at ABC, which shot a presentation but passed on giving it a series pickup. ABC Studios remains the production entity on the project — and is only too happy to see it get a second chance at the Peacock.

Among other projects, ABC’s comedy “Wright vs. Wrong,” starring Debra Messing as an tough conservative pundit, was first developed last year.

“There’s so much that’s wasted every year,” says a top creative exec at a Big Three net. The new mantra of pilot season, she jokes, ought to be “reduce, reuse, recycle.”