THE FALL TV SEASON : HOPE FOR ‘SPENSER,’ ‘MacGYVER’ SEEN : NEW SERIES FACING ‘KILLER’ TIME SLOTS

They’re called “killer” time slots--prime-time periods in which the competition from two networks is so formidable that it would be expected to decimate anything placed there by the third.

ABC is facing the most obvious of these deathtraps on the new season’s schedule with two otherwise potentially promising shows. They are “Spenser: For Hire,” which premieres Friday, Sept. 20 with a two-hour pilot at 9 p.m. and then moves the following week into its regular 10 p.m. slot, and “MacGyver,” which will air Sundays at 8 p.m. beginning Sept. 29.

Each would seem to have some of the prerequisites for success.

“Spenser,” which is filmed in Boston, stars Robert Urich, a charismatic and recognizable screen figure, as the literate detective of Robert Parker’s popular novels. Urich has a solid track record with ABC, having starred in “Vega$” from 1978 to 1981. So does “Spenser’s” executive producer, John Wilder, who produced “The Streets of San Francisco.”

“MacGyver” brings former soap opera star Richard Dean Anderson to his first headlining role as a scientist-adventurer. Network tests showed that Anderson appeals not only to the expected women and teens but also to men and older viewers. And this show, too, is backed by successful TV track records: Its executive producers are longtime ABC star Henry Winkler (Fonzie on “Happy Days”) and John Rich, who directed and produced “All in the Family” (on CBS), among other shows.

Yet Lewis Erlicht, president of ABC Entertainment, readily acknowledges that both shows “will go in and be third in the time period. There’s no doubt in my mind.”

The opposing schedules tell the story behind Erlicht’s admission.

“Spenser” will air opposite CBS’ “Falcon Crest,” the 10th most popular series last season, according to the A.C. Nielsen ratings, and NBC’s “Miami Vice,” proclaimed by both critics and viewers as one of last season’s hottest new shows.

“MacGyver’s” competition will be “Murder, She Wrote,” last season’s 8th-ranked show, and Steven Spielberg’s “Amazing Stories,” an untried product but one that media analysts expect to earn healthy ratings at the outset simply on the basis of Spielberg’s movie-making reputation.

The crunch for the two new ABC shows--more so than for others premiering this season--is that, in these time slots, CBS and NBC are going after slightly different audiences with proven or expected hits, in theory leaving no significant demographic group available for a new contender.

“Falcon Crest,” for example, is strong with women and aims at CBS’ traditionally older audience. “Miami Vice,” meanwhile, skews to a younger, more male audience. Given “Falcon Crest’s” past performance and “Miami Vice’s” extremely good showing in reruns this summer, they together could draw more than 60% of the total viewers tuned in on Fridays this fall. But all three networks combined earned only 81% of the available viewers in that 10 p.m. time slot last year, with the other 19% tuning into cable, independent stations or PBS. If viewing patterns remain the same, “Spenser” may have fewer potential viewers than the number that watched last year’s occupant of that time period, “Matt Houston,” which ABC canceled.

Likewise, “Murder, She Wrote,” with across-the-board age appeal but tilting toward the older viewer, and “Amazing Stories,” predicted by analysts to hone in on younger viewers, between them could capture the vast majority of network TV viewers. (Though “Amazing Stories” is a half-hour show, common wisdom says that anyone who sticks with it for a full episode is more likely to stay tuned to its follow-up, “Alfred Hitchcock Presents,” than to join “Murder, She Wrote” or “MacGyver” in midstream.)

So what are a couple of lonely guys like Spenser and MacGyver to do?

The answer from ABC is: Be patient, and maybe, if you’re lucky, you can move to a better time slot.

“You don’t have to be second or first to do well in a time period where you have modest expectations,” Erlicht said.

And how modest are his expectations? “You can’t give any cutoff,” he said. If a show attracts only 10% of the available viewers, “you know the handwriting’s on the wall. But you can be third and you can get qualitative research showing the audience is liking the show.”

The big break for “MacGyver,” he said, will come after Game 2 of the World Series, set for broadcast Oct. 20 from 6:30 to 10 p.m. on ABC. On that evening--and one week later, if the Series goes seven games--”MacGyver” could benefit from post-game viewers who resist changing the channel. Then, he believes, “MacGyver” could have a fighting chance for the 18-to-49-year-old viewers targeted by “Amazing Stories.”

“It will take as long as December or early January,” Erlicht said, to see for sure if “MacGyver” is building viewership.

“Spenser” is in for an even tougher battle, he said, since both opposing programs are proven hits. “But you’ve got to throw in something that you believe can eventually work,” he said.

“If you have a show that’s in a killer time period and you keep putting show after show after show in there and it’s just fodder, you might as well ride with something you believe in. Or if it shows me something in that time period, maybe it can be moved.”

“Spenser’s” Wilder said that he already is eyeing the 10 p.m. Tuesday slot soon to be occupied by “Our Family Honor.” “Spenser,” he reasons, would be extremely compatible with ABC’s 9 p.m. detective comedy, “Moonlighting,” because its star, Cybill Shepherd, and Urich both have what he calls “movie magic” appeal.

(However, that assumes that “Our Family Honor” will fail, and Erlicht said he has high hopes for that show, too.)

Rich said that he, too, “suspects” ABC would eventually move “MacGyver,” but until it does, his concession to the bad time slot is “to do very exciting openings--big stunts and impressive sequences.” The premiere episode, for example, opens with MacGyver suspended on the sheer face of a cliff thousands of feet above the ground--from which he eventually propels himself using a hastily improvised rocket launcher.

“If people will come in and sample the wares,” Rich said, “I think they’ll return.”

Wilder said he is focusing on the show’s execution, regardless of the network’s scheduling. “To the degree to which execution can affect ratings,” he said, “we’re doing our part.”

“Personally, I’ve never had an instant success,” Rich said, citing “All in the Family,” as well as “The Dick Van Dyke Show,” which he directed. Both had tough competition, both had unimpressive early ratings and both were “reluctantly” renewed by the networks, only to become two of the most memorable shows in TV history.

Despite the shoot-out waiting for “MacGyver” and “Spenser,” ABC reportedly is sticking to its promise not to interfere with producers, as it had in previous years when it insisted on certain levels of glamour and action.

“I think they’re much less jumpy now,” Rich said. “They’re finally getting the idea that you have to be patient with shows.”

“The one thing that’s irrefutable,” concluded Erlicht, “is if you have a show that’s executed great, if you believe in it, if there are stars and good characters, you should ride with the show. That’s a change for us. It’s something you learn.”