MOVIES : COMMENTARY : The Actor’s Trade, or How Do They Do That? : In new films together and apart, Bill Murray and Robert De Niro reflect different styles of an ephemeral art

No matter how popular or celebrated actors and actresses become, their careers invariably tend to be of the feast-or-famine variety.

Long gone are the more orderly studio days, when performers could depend on being forced to work regularly on whatever was handiest whether they wanted to or not. Now vagaries of production schedules and studio release patterns, not to mention agents’ whims or even the quirks of their own psyches, may mean that years can go by between on-screen appearances for even the most sought-after of stars.

Or, as is the case now for Robert De Niro and Bill Murray, the reverse can happen. Both these men can currently be seen in two films apiece, not only “Mad Dog and Glory,” in which they share billing and the screen, but also “Groundhog Day” for Murray and “This Boy’s Life” for De Niro. This double vision offers a rare opportunity to not only study the very different types of acting the two men practice, but also to understand what makes them as good as they are.

For whatever else the films offer, they display the skills of both actors to exceptional advantage. Taken together, De Niro’s two films show the dizzying breadth of character he can play, while Murray’s films demonstrate that precise work in a narrower range can be equally rewarding.

Murray’s acting had been in short supply of late. After making a splash on “Saturday Night Live” in the late 1970s, he provided memorable turns in both “Tootsie” and “Ghostbusters” and seemed to be heading toward a limitless future with his trademark deadpan persona.

Then Murray made a pair of missteps common for actors who are viewed, with unfortunate and misplaced dismissiveness, as mere personalities, as people who can only play one type of role--a variant of themselves--and only play it one way.

Murray first tried to prove that he could play someone very different from his image by writing the script for and starring in a misbegotten version of Somerset Maugham’s moody novel “The Razor’s Edge” in 1984. Then he went in the opposite direction and decided that his sensibility was so foolproof it didn’t matter what kind of nonsense he put it in. “Scrooged” was the disastrous result in 1988.

Now, five years later, Murray is back with two films in which he plays very shrewd variations of his core persona. In “Mad Dog and Glory,” he marries his darkly comic aura to a gangster personality and shows up as Frank Milo, a hard guy with a weakness for comedy and a yen for affable companionship. Given how misanthropic Murray’s wit is, it is both clever and believable to turn him into someone who could turn your life into a raging sea if he so desired.

In “Groundhog Day,” Phil Connors starts out as a standard-issue Murray character, hostile and abrasive. The film’s deft twist is that in repeating the same 24-hour time span day after day, Connors comes to see how lacking that character is, and what changes he will have to make in himself if he is going to get any kind of satisfaction out of his curious life.

What characterizes both these roles is how completely thought out they are, how well they understand what Murray can do and how adroitly they take advantage of that. Murray seems finally to have accepted himself as he is, to understand that having to stay within a certain band can be an incentive to creativity, not a hindrance. Just look what it did for Clint Eastwood.

While people who have met Murray say that his personality off screen is very much like what you see on camera (his ad-libbing of his lines when he and groundhog Punxsutawney Phil co-drive a car being a case in point), De Niro in person is quite unlike anything he’s done on screen.

Affable but not talkative, De Niro gives off an uncanny sense of more or less marking time between roles, of being, almost like a priest, in constant readiness to take on the next performance of a vital ritual. His off-camera quietness underlines how much of a transformation acting is for him, how he puts on and takes off roles like magical costumes he can lose himself in absolutely. Becoming another character seems to allow him to emotionally erupt in ways he doesn’t ordinarily indulge in.

Certainly in “Mad Dog and Glory” and “This Boy’s Life” De Niro has a pair of exceptionally diverse roles, and he does very well by both. Though he has done non-combustible guys with some regularity in everything from “Bang the Drum Slowly” to “Stanley & Iris,” it is fascinating to see how much attention to nuance and custom tailoring he can bring to each new variation.

His ironically nicknamed Wayne (Mad Dog) Dobie, for instance, is a man so set in his routine that when attractive Glory (Uma Thurman) shows up unexpectedly at his door, he stands there for the longest time without any kind of reaction at all, a study in slow-motion bafflement that expresses the essence of his character.

This same sense of what is appropriate keeps De Niro from using his usual broad, sweet smile here, and also allows him, despite all he learned about boxing in “Raging Bull,” to appear awkward and untutored in this film’s climactic fight scene.

Even more impressive is what De Niro does in “This Boy’s Life,” fastening on the role of Dwight Hansen in a way that is dazzling. Though explosive characters have been a mainstay of his career, and though De Niro, like any actor, can use overly familiar mannerisms or head off in misguided directions, he couldn’t be more on target here. More than anything, his Dwight is set off by its complexity, a role so finely realized down to the uncannily correct rural Northwest accent that it is impossible to see it without shuddering.

Unlike the tattooed space invader he played in “Cape Fear,” a cartoon from beginning to end, Dwight’s believability as a monster is in direct proportion here to how real he is, making this probably the most frightening character the actor has ever played. This reality is a product of shading and ambivalence, qualities that began in Tobias Wolff’s memoir, continued in Robert Getchell’s excellent screenplay and were completely embraced by De Niro in his turn.

As Dwight, the narrow, self-righteous tormentor, decimates his young stepson’s life, it is constantly an open question whether he is more limited than bad, more warped than actually evil. De Niro has been able to understand and convey Dwight’s crucial belief that he is doing the boy a favor by treating him the way he does, a notion even the victim for a time agrees with. When Dwight’s blue-collar resentment at the lad’s wealthy, unapproachable father is added to the mix, it makes Dwight the bully paradoxically feel the most aggrieved party in the family, sullenly proclaiming, “I know a thing or two about a thing or two” to a disbelieving world.

And when, in the film’s climactic scene, Dwight screams “What about me?” the amount of genuine agony in that howl makes the tortures he has inflicted on the boy in the name of his own insecurities that much more believable and horrific. This would be a heroic performance at any time, but to see it now, in tandem with “Mad Dog and Glory,” is to gain an additional insight into why De Niro is considered such a master of this most evanescent craft.