The most interesting person on late-night television is a 47-year-old Scottish reformed alcoholic high-school dropout, drummer, actor, comic and novelist named Craig Ferguson, who since 2005 has been hosting “The Late Late Show,” which follows David Letterman’s “Late Show” on CBS. He is not the only talk show host whose work I like, or even the only one I’m tempted to call a genius -- the other would be Letterman, whose Worldwide Pants produces Ferguson’s program -- but he’s doing something that, though constructed within the recognizable parameters of a late-night American comedy talk show, is all his own thing: personal and free, mindless of rules and yet in control of the medium. It is direct and intimate in a way that hearkens back to earlier, less frilly days of television, and it is also hilarious.

There has been a “war” in late night, as you certainly have heard -- well, not so much a war as a schoolyard brawl between one of the older boys, Jay, and one of the younger ones, Conan, that saw the former transferred and the latter expelled. Catcalls flew in from the sidelines, but Ferguson, though he has had some fun at the expense of NBC, who whipped up the fight in the first place, has remained basically neutral as regards the combatants. He also likes to say that he is not exactly in the same game as they are. “I know this isn’t really a late-night talk show,” he told his viewers recently, “it’s just something that happens about the same time.” The truth is, he really isn’t in the same game.

Time slot, as much as viewership, is how importance is measured in late night: The later your start, the fewer people left awake to watch you, the less you matter in the world that defines success by numbers. Conan O’Brien’s insistence that a show that began at 12:05 was by definition not “The Tonight Show” was, among other things, a matter of chronological status: It meant that he’d be competing not against Letterman but Jimmy Kimmel.

Ferguson goes on even later, at 12:35 a.m., and though he has been regularly mentioned as a likely successor to Letterman, he seems in no rush to see his boss retire.

“I have no ambitions beyond being comfortable in what I do for a living -- and earning a living,” he said recently in his office at CBS’ Television City, where “The Late Late Show” tapes in a surprisingly small, converted photo studio. He was stretched out on a couch, beneath a plane’s-eye-view of a landing strip. (He earned a pilot’s license to conquer a fear of flying.) He was naturally more muted than when he is being “TV’s Craig Ferguson,” as he introduces himself on air, but he is volubly passionate about maintaining the independence and the integrity of his work.

“We have no promotion, we’ve got no money -- it’s the cheapest budget of any of the late-night shows -- probably Carson Daly’s too. We get nothing. But we do have a huge advantage in that they let us do what we want. And I would take that trade.”

Like no other

What Ferguson does is not so much make lemons into lemonade as exploit the actual properties of the lemon itself. He has no band, no sidekick. (He will “sidekick himself” as the need arises.) “What it feels like on this show,” he said, “is that all the kids are by the riverbank fishing and I have a stick with a piece of string and a bent hook and the rest have fantastic equipment, but every now and again I catch a fish, to the surprise of everyone else -- and me.”

Yet the lack of amenities is also the foundation of an aesthetic, refined into something relaxed and strange and -- though it can involve shark puppets and a frightening impersonation of Larry King -- pure. Ferguson’s set has grown simpler since he started: It’s empty enough now to play Beckett on, just a couple of chairs and a desk empty but for a mug in the shape of a coiled rattlesnake.

What fills the space is Ferguson himself, mostly as himself, though sometimes in costume and sometimes at the unseen end of a hand puppet. He carries the show from first to last, a protean excursion that begins with his customary “It’s a great day for America” and ends with the question “What did we learn on the show tonight, Craig?” or "¿Qué aprendimos en el programa, Señor Craig?” since his vow to learn enough Spanish to do a whole show in that language by the end of this year. What happens in between will be done in a variety of voices and attitudes, in colliding waves of sense and nonsense.

In January he began his sixth season, and at the end of last year he marked his 1,000th episode by performing the entire show as his crocodile puppet Wavy. His audience, which began a little shy of 2 million viewers, is now a little over that mark -- as a rule, he was beaten by Conan O’Brien before O’Brien moved from “Late Night” to “The Tonight Show,” and he beats O’Brien’s replacement, Jimmy Fallon. In December, he won a Marie Claire online poll as the late-night host readers would most like to sleep with. “I’m genuinely freaked out by this,” said the thrice-married father of one. (His son, Milo, is 8.) “I blame people that don’t have high-def television.”

In fact, it’s not hard to see why he won. He leans close to the camera -- confidentially, flirtatiously putting his hand upon it, and by extension upon the whole viewing audience. Where most late-night hosts hit their mark and stay there, Ferguson moves back and forth in space, talking with his hands, cocking a conspiratorial eye, hanging his head in a coy impression of shame, shaking himself as if to reset his brain. His monologue, which may or may not reflect a list of “bullet points” put up on the teleprompter, might contain jokes; but they are cushioned within a larger, often thematic frame, and by Ferguson’s frequent digressions, so they play as part of an extended string of thoughts. (Recently, he did the monologue in the middle of the show because “you’ve got to change it up for yourself or you lose your mind.”)

Though he styles himself a “vulgar lounge entertainer” and can go as low as the network censor will allow, he is certainly the only late-night host who would do several minutes on the death of J.D. Salinger or respond to recent guest Claire Danes’ saying that her father-in-law was a moral philosopher by asking “Pre- or post-Enlightenment?” with a quote from Kierkegaard for a kicker. On the other hand, he loves the show “Mythbusters” and the word “farty.”

Ferguson showily shreds his notecards at the start of every interview, like a pop musician announcing that he has thrown away the set list. Some of his conversational strategies are not much different from what you’d use to draw out a stranger at a party. (“Where are you from?” is a favorite question, because he likes to talk about places he knows, and he knows a lot of places.) The effect for the viewer is of being present at a meeting of humans, not of being sold a product. Guests come and go often without having discussed the thing they had ostensibly come to promote.

“The best guests tend to be those who are generous of spirit because that’s the spirit of the show,” Ferguson said. “It’s an old improv game: I ask you a question, you don’t say ‘No,’ you say ‘Yes.’ I say, ‘Were you ever in Australia?’ ‘Yes -- and no. I was in New Zealand.’ Or ‘I’ve seen a photograph of a kangaroo.’ Bring something to it ‘cause I ain’t gonna ask you what practical jokes you played on a movie set, ‘cause I don’t care, and I’m not going to ask anything that doesn’t interest me, because that’s not my job.”

Making his own way

Ferguson, who grew up near Glasgow, Scotland, and is now an American citizen, was previously best known here as the boss on “The Drew Carey Show.” He logged a lot of miles before coming to late night: He delivered milk, drummed in rock bands, worked in an adding machine factory, in construction and as a bartender before he began doing stand-up in local discos. “Now, in a town like Glasgow on a Friday or Saturday night when you stop the music in a dance hall for a guy to try to get some laughs,” he said, “you develop a certain frantic, partially aggressive, partially desperate, certainly vivid style.”

As to where and when he was raised, “I think that clearly it has an influence, to be coming of age during the punk rock era, to come from a difficult and sporadically violent background, to have been in and out of such chaos, I think it actually helps. But I don’t know for sure. I used to believe, like many people who come from poor backgrounds, that it gave me an edge, but I think that’s just something we have to tell ourselves to get by sometimes. I don’t believe that anymore. Children of privilege can be just as talented and clever as anybody else.”

When “The Late Late Show” came his way, he wrote in his memoir, “American on Purpose,” “I was bored with acting . . . and I hadn’t done stand-up comedy in ten years. I was thinking maybe I should go back to drumming or delivering milk.” But he found his metier and has only grown better at it. He has hit his stride.

Comedy is in many ways a young person’s game; that’s where the fashions change. But what Ferguson does takes seasoning; his most remarked upon moments are also his deepest: his eulogies for his father and then his mother; his thoughts on the proper targets for comedy on the coincidental occasion of Britney Spears’ lost weekend and the 15th anniversary of his own hitting bottom and getting sober; and the show he devoted to Archbishop Desmond Tutu. But these episodes were also very funny.

“I doubt very much if you sat down with a focus group they’d say, ‘Let’s get the reformed alcoholic punk-rock 45-year-old drummer from another country with a broad accent -- that’s the way to go in the late-night world,’ ” said Ferguson. “ ‘Cause no conventional wisdom is going to do that for you. But the thing about conventional wisdom is that it doesn’t work in art -- if that’s what we do.

“I don’t think I’ll get away with this forever,” he concluded. “I try and live my life in bite-size chunks. It was a lesson I had to learn when I got sober, but then it became a way of life, a philosophy -- live your life a day at a time. Especially because the temptation, especially when you’re doing OK, is to think, ‘In a couple of years I’m gonna get this, and then I’ll have this.’ And then what?”

robert.lloyd@latimes.com