Just Outta the Gate, It’s Dave by a Head : Television: Early results show Letterman in the late night lead, followed by Jay Leno and, finally, Chevy Chase.

One month has passed since late-night television turned into a high-stakes horse race between a pack of thoroughbred talk-show hosts. The early results:

David Letterman’s “Late Show” turned in a decisive win, Jay Leno’s “Tonight Show” fell to second place and “The Chevy Chase Show” has yet to show that it can compete.

Although Letterman’s ratings have dropped gradually since his premiere week, when he had double the size of Leno’s audience, he is still maintaining a comfortable lead on CBS over his competitors. It’s the first time “The Tonight Show” has been displaced by another talk show for such a sustained period.

“This is certainly on the high end of our expectations,” said David Poltrack, senior vice president of planning and research for CBS. “We were prepared to be the second-place show.”

Executives at all three networks stress that these figures are like early returns on a long election night: not necessarily indicative of the final outcome. But, for now, Letterman has settled around a 5 rating. After a rocky couple of weeks against the new competition, Leno has climbed back into the low 4s, roughly the level he had before Letterman premiered on Aug. 30. And after three weeks on the Fox network, Chase, who has a half-hour head start on his competitors, is in the 2s and falling. (Each Nielsen ratings point represents 942,000 homes.)

Newcomer Conan O’Brien, who took over Letterman’s old 12:35 a.m. “Late Night” show on NBC two weeks ago, received a 2.2 rating his first week and will probably dip below a 2 when the national ratings come in for last week. Letterman used to rate in the mid-2s when he did “Late Night,” but that was with a stronger “Tonight Show” lead-in.

In syndication, meanwhile, Arsenio Hall, whose once popular talk show was pushed by many TV stations to the early-morning hours to make room for Letterman and Chase, broadcast reruns during the week of Letterman’s premiere and tumbled 19% from the previous week to a 2.1 rating. The next week, during Chase’s premiere, Hall returned to original episodes but remained flat at 2.1 (those are the most recent national numbers available for syndication).

In the same two-week time frame, reruns of Rush Limbaugh’s syndicated show sank to a 2.7 average, down substantially from the 3.3-national rating Limbaugh enjoyed for his debut season last year. Limbaugh premiered his new season on Sept. 13, however, and Multimedia Entertainment is projecting a 3.3-national rating for that week based on preliminary ratings.

CBS’ Poltrack said the network had not anticipated Letterman remaining ahead of “The Tonight Show” this long at the outset. “We thought we would be competitive with Leno,” he said, “but we thought we would stay behind him until we could get rid of the clearance handicap.”

The “clearance handicap” refers to the fact that Letterman’s “Late Show” airs at 11:35 p.m., when the network wants it to, in only about 67% of the country. In other areas, CBS stations delay it past midnight--when there are fewer viewers--to air profitable syndicated programming. On the other hand, Leno’s “Tonight Show” clears almost everywhere at 11:35.

As a result, many advertisers predicted that Leno would rule in the ratings until sometime next year, when more CBS stations are expected to switch Letterman to the 11:35 slot once they play out the syndicated programming they already had purchased.

With “Late Show’s” strong early showing, which he expects to continue, Poltrack said he is going to take his case to CBS stations and encourage them to move up the start time of the show earlier than next year, which will help Letterman’s ratings even further.

But hold on, said Eric Cardinal, vice president of program research for NBC. This race has just begun, he said, and the early predictions that put Leno on top were for the first year, not the first month.

“I don’t think that this game is over,” Cardinal said. “Those predictions were for the long term. Come back to us in six months and let’s see who’s on top. The people who are calling this a Letterman win after three weeks are being premature.”

Cardinal does not agree with Poltrack that Letterman’s numbers have bottomed out, arguing it’s too soon to tell. Cardinal explained: “As things shake out, you’re going to see ‘The Tonight Show’ really return to its rightful place.”

One thing is certain: Late-night TV viewing is up significantly as a result of the new competition. An A.C. Nielsen analysis during the first two weeks of the late-night battles showed that the number of households using television during that time period was 13% higher than the same period in 1992.

“When Letterman came into the time period, I don’t think everybody expected him to do as strong as he did,” said Robert Wohler, supervisor of news research for ABC. “But what we have found, the majority of his viewing audience didn’t come from the other talk shows. He has brought new viewers into the time period.”

Wohler noted that “Nightline” on ABC, which is driven by a much older audience of 50-plus viewers than its talk-show competitors, has averaged a 5 rating during the first three weeks of the late-night wars--just what it has been averaging all year long.

“We anticipated very little erosion in our audience, other than some sampling the first week,” Wohler said.

With so many choices now, much of the competition appears to hinge on the guests on each show. During his second week, Letterman’s ratings spiked dramatically when he had Vice President Al Gore on. The next week, Leno beat Letterman the night Burt Reynolds was on discussing his break-up with Loni Anderson. And last week, “Nightline’s” overnight ratings soared when President Clinton appeared.

In examining the competition between Letterman and Leno, Wohler said: “Letterman will have a younger audience, and ‘The Tonight Show’ will have an older audience who will stick with Leno, although he will pick up the younger viewers on nights when he has the hot guest. But it’s hard to say who will end up in first.”

Fox appears to be the only real loser in the early leg of the late-night TV race. Chase scored well in the research Fox did leading up to his debut, and most TV analysts believed the sky would be the limit if he put on a good show. But the movie star, a first-time talk show host, has been skewered by critics, and viewership has been declining.

Chase received a 4.4 rating for his premiere week, but he toppled to a 2.8 his second week and even lower last week, although final numbers are not in yet.

Questions have begun to be asked about how long Fox can afford to run with Chase if the ratings don’t improve. In May, Fox stations averaged a 3.2 rating in the time period he now occupies, and that was when they were running syndicated programming for which they kept all the advertising revenue (they share advertising time with Fox on Chase’s program). Competing network executives don’t see how Fox stations can continue at that rate.

Andy Fessell, Fox’s senior vice president of research and marketing, said that the network is prepared to stick with the show, establishing a foothold in the late-night arena and building from there.