FINAL COUNTDOWN TO ACADEMY AWARDS : The Ratings Envelope, Please: Will Oscar Win the Time Slot or Lose to Basketball’s Slam Dunk? : HOLLYWOOD PLAYS THE TV PERCENTAGES

For the last three years, despite its high drama and hoorays for Hollywood, Oscar night has been sliding in the TV ratings.

It’s not been a big drop--not the kind that would cause the lords of Oscardom to impale themselves on a Nielsen point. Still, can anything be done to reverse this descent?

The question was put to Samuel Goldwyn Jr., who is producing tonight’s 59th annual Academy Awards proceedings that ABC will air live at 6 p.m. from the Los Angeles Music Center’s Dorothy Chandler Pavilion.

“I think,” he said, “if I can solve the ratings problems of television, they’ll give me three networks.”

Goldwyn, in other words, is philosophical about it. “The Academy Awards are the Superbowl of show business,” he reflected. “And sometimes the Superbowl’s up, sometimes it’s down.”

The chief competition for ABC’s Oscar telecast will be CBS’ live coverage of the NCAA basketball championships from New Orleans. NBC’s prime-time wares are “ALF,” a new TV movie called “Stone Fox” and a repeat of a “You Again” episode.

CBS’ basketball telecast is getting a jump on the Academy Awards by starting at 5 p.m. (Channels 2 and 8), an hour that ABC-owned KABC-TV Channel 7 will fill with live coverage of the arrival of tuxedoed and begowned Oscar hopefuls, celebrities and various spear-bearers at the Music Center.

The CBS hoop tilt “should do very well” in that first hour, said David Poltrack, CBS’ audience research chief. Later, there doubtless will be some channel-switching, from basketball to the main Oscar event and vice-versa.

In 1982, the last time CBS’ basketball went one-on-one with Oscar, Oscar easily won the contest, although basketball got a respectable 31% share of the audience, Poltrack said.

This time out, he predicted, the basketball joust--pitting University of Syracuse against Indiana University--will attract about a 30% share of the audience.

Poltrack’s biggest worry: that one team will get a commanding early lead, making it appear that the game is what lawyers call nolo contendere. This has been known to cause massive tune-outs.

As he puts it, “If you get a blowout, you’re in big trouble.”

Oscar night’s record “up” was the halcyon year of 1970. That year, one in which John Wayne won the only Oscar of his long career for “True Grit,” the academy telecast had a 43.4 rating, or 26 million homes, and a record 78% share of the prime-time TV audience.

Cut to 1984, when Oscar night, rampant with endless oratory, rolled on for 3 3/4 hours. It got a 30.3 rating and had a 50% audience share. A post-mortem resulted in a shorter and far crisper edition in 1985, when winners got only 45 seconds to thank everyone in the world or face the hook.

Alas, the streamlining didn’t help the show’s ratings. The telecast was seen in nearly 23.5 million homes. But that was about 1.9 million fewer than the previous year. The audience share was down too to 45%.

Last year, despite a heavy emphasis on old-fashioned glamour, Oscar night again suffered a slight loss of audience. It was seen in 23.4 million homes, with 43% of viewers tuning in.

Hollywood’s Big Night never fails to win its time period, but is it possible to get it back to the Nielsen glory of yesteryear?

Or is that the impossible dream, particularly now that network audience levels are in decline, down to a three-network average of 75%--compared to 90% in 1979-80--because of increased competition from cable TV, independent stations and videocassettes?

“I don’t know that it’s impossible, but it’s improbable for all the reasons we know,” said Larry Gelbart, co-producer of CBS’ much-honored “MASH” series and writer of the 1985 Oscar show that drew praise from critics for its tight production.

For one thing, he said, referring to the increasing number of award shows on TV, “the awards business is such a competitive business today. Everyone gets an award and, as we know, it’s at the point where award shows get an award.”

(He speaks only partly in jest. In 1980, Broadway’s televised Tony Awards won TV’s Emmy Award as best special. And last year, Roy Christopher, production designer of tonight’s Oscar show, won an Emmy for his sets for the 1986 Oscar show.)

“But I think the other shows are probably aiming at a wider audience,” Gelbart mused. To get those viewers, he said, “you have to be able to promote--in advance--something which is going to attract them. You can’t get a good audience just by virtue of having done a good show.”

Ergo, he said, “somewhere in the planning you have to offer something more than handing out the statuette.” He chuckled. “What that is, I don’t have at my fingertips.”

Producer Goldwyn, whose show airs here on Channels 7, 3, 10 and 42, agreed that there are too many award shows nowadays. Still, he noted, the Oscar show remains “the highest-rated program of its kind in show business anywhere in the world.”

It also has a worldwide audience. According to William Vitale, director of international television for ABC’s distribution arm, tonight’s show will be seen live or on a tape-delay basis in 85 other countries, including China, where it first aired in 1984.

Sixty of those nations--from Great Britain to El Salvador--have opted for a taped 90-minute edition, an “Essence of Oscar” program distilled from tonight’s broadcast and sent overseas by satellite before dawn Tuesday for broadcast.

The other markets will take the full show--scheduled for three hours--and either will air it live or tape it for later broadcast. The live contingent includes Canada, Mexico, Jamaica and, although it will be in the wee, small hours of the morning when it gets there, Spain.