LAYING DOWN KELLEY'S LAW; TV'S PROLIFIC, HIGHLY SUCCESSFUL WRITER-PRODUCER PUSHES ENVELOPE YET AGAIN WITH SWEEPS-DRIVEN CROSSOVER CONCEPT TO HELP STRUGGLING `PRACTICE' WHILE SUSTAINING HIT `ALLY MCBEAL'.

Byline: Keith Marder Daily News Television Writer

For a man who goes to work looking like he just rolled out of bed - a tousled mane of thinning hair, razor stubble, wearing jeans and a shirt he most likely chose because it was closest to the closet door - David E. Kelley keeps a most stringent regimen.

In by 9 a.m. Out by 6 p.m. Fifteen-minute breaks to allow the fog to lift from one project to the next.

And for Kelley, one of television's most prolific writer-producers, those fixed hours are enough to create projects that are as successful as they are unique.

``Doogie Howser, M.D.,'' ``Picket Fences,'' ``Chicago Hope'' and his two current projects, ``The Practice'' and ``Ally McBeal.''

For a guy whose grandmother used to call him a stinker, he has never created one.

From his cluttered desk at Ren Mar Studios in Hollywood, the characters' voices shoot into the most talented fingers in television writing, through a ballpoint pen and onto a legal pad.

These are just a few of the traits that separate Kelley from all the other kids. And he has a six-figure income and a bucket full of Emmys to show for it.

Kelley is a fiercely private man with a square jaw, brooding lips and deep-set eyes that make you wonder what he's thinking - which, most likely, is a heck of a lot more clever than anything you're thinking.

He chooses his words carefully and prefers to talk about his shows rather than himself. A testament to his low-key manner is his remarkable ability to keep his marriage to high-profile actress Michelle Pfeiffer - with whom he was set up on a blind date - from becoming tabloid fodder.

His shows, most notably ``Ally'' and ``The Practice,'' however, have sold many magazines during the past months.

And on Monday night, in the name of ratings, the two worlds he has created will collide.

The Boston-based courtroom dramas, though hatched from the same mind, couldn't be more different.

``Ally McBeal,'' a hit right out of the gate, centers on a capable yet vulnerable woman attorney who works for a small and high-priced firm. ``The Practice,'' in contrast, focuses on a blue-collar firm with an earnest but ethically pliable leader who bends the rules to keep the financially strapped company afloat. The show initially was time-period-challenged but finally has an audience worthy of its critical praise and quality.

``Ally is trying to navigate her personal world,'' said Kelley, 41. ``Bobby is definitely a little bit of a lost soul.''

Now, in an unusual sweeps stunt, the two casts will meet.

The coincidental scheduling of Kelley's two shows - ``Ally'' airs at 9 p.m. on Fox (Channel 11), leading directly into ``Practice'' at 10 p.m. on KABC (Channel 7) - and their common Boston settings make the crossover an interesting proposition.

The two-hour extravaganza finds Ally's law firm representing a murder suspect, a case that stretches her and her colleagues' knowledge of criminal law. To mount a proper defense, they enlist the help of Bobby Donnell's firm (``The Practice'') as co-counsel.

The interplay between the two casts is, at times, wonderful. Kelley took the liberty of inserting plenty of inside jokes from ``Ally'' during both of the linked episodes. A note for the Ally-illiterate: When someone says, ``bygones,'' it means that, despite a crude comment, they mean no harm; men and women share a large public bathroom in the posh office building; and when John Cage (Peter MacNicol) says ``Poughkeepsie,'' he's trying to control his stutter.

The two hours of television live up to Kelley's standard of excellence. The story moves well and has enough twists to keep you from turning.

It was once unfathomable to think of two television networks working together on a promotion during the competitive May sweeps period. The closest any network has come to the crossover concept was when one of NBC's ``Homicide'' characters appeared on Fox's ``The X-Files.'' Kelley once tried to pull off a similar stunt with ``Picket Fences'' and ``The X-Files,'' but CBS pulled out, he said.

This time, he's at the helm of both shows in question.

Having two shows from different networks work together like this is like the Lakers lending their players to the Clippers for an important National Basketball Association game.

The idea has puzzled some affiliates who are eager to garner as many viewers as possible during the four-week sweeps period.

ABC is sending viewers to Fox at 9 p.m., all but programming against its newsmagazine ``20/20.'' And Fox is sending viewers away from its local news in many markets during the vital period during which ad rates are set.

Some affiliates protested the cross-pollination, but that couldn't stop it. When the person pushing for the stunt is David E. Kelley, a producer everyone wants to be in business with, exceptions become the rule.

``I just think he's much more talented than the bulk of producers and is responsible for provocative television,'' said ABC Entertainment president Jamie Tarses. ``He has great instincts, and his characters are likable and relatable. He really makes you think.''

Said Peter Roth, president of the Fox Entertainment Group: Fox's Roth: ``Maybe he has tapped into something in his brain that the rest of us haven't found yet. He is otherworldly in his talent. I read David Kelley scripts for pleasure - like books. I know it sounds corny, but he is a gift to the American viewing public.''

Actors are attracted to the material Kelley conjures up like big-haired teen-agers to a mall.

Calista Flockhart (Ally McBeal), one of a few breakout stars this season, never had worked in television. A stage actor of Broadway caliber who happened to be a fan of ``Picket Fences,'' Flockhart loves Kelley for his mind.

``I saw an opportunity to play a great character with a lot of contradiction and complexity,'' Flockhart said. ``I am committed to who the person is. She overreacts. She makes mistakes and acts on impulse.''

McBeal fights, wears really short skirts, has man problems and sometimes sees imaginary dancing babies.

Donnell (played by Dylan McDermott), the Alpha character in ``The Practice,'' is a steel-eyed hunk who spends as much time fighting back bill collectors as he does opposing attorneys.

As is McBeal, Donnell is a rich character who is far more gray than black and white.

``What he writes comes from somewhere intimate,'' said Michael Balducco, who plays blue-collar Jimmy Berlutti on ``The Practice.'' ``That kind of writing is special for actors. It's not only from his heart, but from our hearts, which makes it special. He even talked to my mother to find out some things about me. I don't even have to memorize my lines because he has it coming out of me.''

And, since nearly every line comes out of one of Kelley's ballpoint pens, his cast knows where to go when they need direction.

``If you don't know what to do in a scene, you can call him,'' said Courtney Thorne-Smith, who left ``Melrose Place'' and now plays Georgia Thomas on ``Ally.'' ``The extraordinary difference between the two shows is, obviously with Aaron (Spelling), he doesn't write. With a show with David, you really feel his vision. I couldn't say no to a David Kelley show, I'm such a fan. I think his writing is extraordinarily honest.''

Princeton pedigree

Kelley is part of the long run of Ivy League-educated Hollywood writers. His pedigree runs through Princeton where, as the son of a professional hockey executive, Kelley was the captain of the hockey team.

He moved on to Boston University Law School, graduated in 1983 and practiced law for three years before taking a job as a story editor on ``L.A. Law.'' From there, he raced up the television writers' food chain.

As a law student, he lived with his grandmother, Mildred Kelley. And like many students of jurisprudence, he had an annoying habit of cross-examining everyone he came in contact with.

``First-year law students just want to grill everybody,'' Kelley said. ``She would ask me to get a loaf of bread and I would ask, `Why is it a loaf of bread?' I used to practice on Grandma all the tme. She would go with it for a while and she would say, `You stinker.' Then it was over. She always got the last word.''

She's still putting Kelley in his place. After the credits finish rolling at the end of each of Kelley's shows, an old woman falls off a rocking chair and her voice cracks with a Boston accent: ``You stinkah.''

She is, of course, talking about her wise-guy grandson, not any of his work. And maybe it's his grandmother as much as it is the next generation of Kelleys that inspires the writer to greatness.

``One day, my children are going to watch this and ask me why I wrote it,'' Kelley said, ``and I want to have a good answer.''

CAPTION(S):

5 Photos

Photo: (1--Cover--Color) Legal eagle

The clout of David E. Kelley convinces two networks to link `The Practice' and (2--Color) `Ally McBeal'

(3--Color) `The Practice'

(4) ``The Practice's'' Bobby Donnell (Dylan McDermott) and ``Ally McBeal's'' title character (Calista Flockhart) combine their defense expertise.

(5) David E. Kelley: ``One day, my children are going to watch this and ask me why I wrote it. I want to have a good answer.''