Saturday Night . . . Dead? : Television: The Big Three haven’t had a Saturday hit in several years and it’s more difficult now for networks to get new shows off the ground.

Twenty years ago, CBS was getting set to launch a programming lineup on Saturday nights that turned out to be one of the most successful and critically acclaimed in the history of television: “All in the Family,” “MASH,” “The Mary Tyler Moore Show,” “The Bob Newhart Show” and “The Carol Burnett Show.”

Since then, however, the number of viewers watching network television on Saturday evenings has plummeted to the point where the entire night has become little more than a tax write-off for the three major networks.

Only 49% of the people watching television on Saturday nights this season have been tuning in to CBS, ABC and NBC--down from 54% last year and 75% 10 years ago. By contrast, for the week as a whole, the networks are attracting about 63% of prime-time viewers this season.

The lack of Saturday support led to fast failures this fall on CBS and ABC, including CBS’ cancellation of “Angel Street” after only three weeks on the air. Both networks have temporarily resorted to inexpensive emergency measures--CBS with movies and ABC with reliable repeats of “Columbo.” NBC hasn’t tinkered as much, but it too is not carrying the same Saturday schedule it started the season with in September.

The weekend programming task has never been easy for the networks, since Friday and Saturday are the two nights of the week when people go out the most. Box-office analyst Art Murphy says that as much as 30% of a film’s weekly revenue comes on Saturday, for example. Nevertheless, it was possible for shows to become hits there: Besides the fabled CBS lineup of the 1970s, “The Love Boat,” “Fantasy Island,” “Diff’rent Strokes,” “The Golden Girls” and “Hunter” all did well on Saturdays.

But the Big Three networks haven’t had a new hit on Saturdays in several years, and as viewers turn to other channels for their entertainment, it becomes more difficult for the networks to get a new show off the ground. Competitors have moved aggressively to fill the programming void.

The smaller, youthful Fox network, which arrived on the scene six years ago, has stepped up to grab 14% of prime-time viewers on Saturday, with such low-cost reality fare as “Cops.” Another 27% of viewers are watching one of the 148 basic cable channels on Saturday nights.

Still another 7% are tuned in to pay-cable channels. Indeed, last May, HBO began premiering all of its big theatrical movies, original HBO movies such as “Stalin” and new episodes of the series “The Larry Sanders Show” and “Dream On” on Saturday nights.

As a result, Saturday has become HBO’s most heavily viewed night of the week. In households that receive HBO, the pay-cable channel generally receives higher ratings than the networks that night.

“We kind of identified the fact that all successful networks own a night or two of the week,” said David Baldwin, vice president of program planning for HBO. “CBS has ownership of Monday night. NBC for years owned Thursday night. With the resources we have, we decided we should set out to own Saturday night.”

Meanwhile, the increased quality of such original syndicated series as “Star Trek: The Next Generation” has helped independent TV stations siphon off 7% of the Saturday night audience. (For those adding, the total audience share exceeds 100% because the A.C. Nielsen Co. measures multiple viewing of TV sets in the same household.)

People watching videocassettes are not factored into those percentages, but their number is also considerable. Video Store Magazine reports that more than one-third of all video rental transactions in retail stores occur on Saturday. And consumers on average are renting 83.5 million videocassettes each week, representing a 5% increase over last year, according to media analysts at Alexander & Associates.

The networks are adopting different strategies in dealing with the Saturday night problem.

ABC is expected to announce in January what will air on Saturday nights for the rest of the season--probably a few series that the network has already ordered as midseason replacements. The real curiosity in the TV industry is over an unusual cost-saving concept under development for the following season, which the network is keeping hushed. ABC is reportedly planning a free-form, two-hour program block involving a mix of comedy, music and entertainment segments bound together by studio hosts.

After the cancellation of two expansive Saturday night dramas this fall--the medieval “Covington Cross” and the road adventure “Crossroads”--ABC Entertainment President Robert Iger told reporters that ABC will no longer pour big dollars into series on Saturday nights because there is no market to support them.

“What works against high-cost programming on Saturday night is the fact that viewing levels are lowest then,” said Larry Hyams, vice president of prime-time audience analysis for ABC. “Even if you get a large share of the audience, because the (number of households using television) are lower, it’s not as cost-effective.”

Other network executives don’t believe that less expensive programming is the way to go.

“When any network decides it’s going to give up a night and put on the cheapest viewing possible because there are no viewers, viewers smell it and it becomes a self-fulfilling prophecy,” said Preston Beckman, vice president of program planning and scheduling for NBC. His network is sticking with its present formula of four sitcoms and a drama, “Sisters,” for the spring.

“There’s no question that if failure is inevitable, then you should fail cheaply,” said Peter Tortorici, senior vice president of programming for CBS. “But I don’t think failure is inevitable here. We have a night people are watching television.”

In recent years, CBS has done little to build an audience on Saturday nights, Tortorici said, because “the stakes aren’t as high” due to the smaller viewing audience. Instead, CBS concentrated on other nights of the week last year to become the top-rated network. Now CBS is ready to tackle Saturday.

When the sitcom “Frannie’s Turn” and the returning “Brooklyn Bridge” failed to produce ratings on Saturdays this fall, CBS removed them and decided to replace them from 8 to 9 p.m. as of Jan. 2 with “Dr. Quinn: Medicine Woman,” which the network co-produces, followed by the returning drama “Raven” and “The Hat Squad,” a first-year police series moving over from Wednesdays.

“Medicine Woman” was at one time scheduled for a 9 p.m. time slot, but Tortorici wanted to wait for an earlier opening in hopes of attracting families. “Medicine Woman” stars Jane Seymour as a strong-willed New England doctor who moves to a frontier town in Colorado during the 1860s to set up practice, only to encounter resistance from locals who don’t want to deal with a female physician.

“We keep getting responses from viewers saying they want family entertainment,” Tortorici said. “Adults want something they can safely watch with their kids. They want a show that provides a family experience. Shows from the past, like ‘The Waltons’ and ‘Highway to Heaven,’ those shows haven’t been around for a long time.”

Loneliest Night of the Week

In the past 11 seasons, the percentage of prime--time teleision viewers tuning in to ABC, CBS, NBC on Saturday night has declined by a third.

82--3: 75 83--4: 74 84--5: 69 85--6: 70 86--7: 69 87--8: 65 88--9: 61 89--90: 60 90--1: 54 91--2: 54 92--3: 49 Source: A. C. Nielsen Co. * Through Dec. 6