"L.A. Law" vs. "Picket Fences." The big showdown? Forget about it! As both now stand, "Picket Fences" is easily and absolutely the better series. "L.A. Law" is a big fat "then" and "Picket Fences" is a resounding "now."

The two weekly dramas go up against each other tonight at 10. NBC's "L.A. Law," on Channel 4, is an old warhorse whose battle scars now appear to be terminal. "Picket Fences," the struggling CBS series on Channel 9, is in its first season and, in its previous Friday night time slot, earned critical support but only so-so ratings.

Both shows are produced by Fox TV, so Fox can't lose. David E. Kelley, who created and produces "Picket Fences," formerly produced "L.A. Law" -- he's the big meanie who sent Rosalind Shays down that elevator shaft -- so there is a certain incidental irony in the race. In terms of quality, however, the race is over. "Picket Fences" wins.

"L.A. Law" is having a miserable season. Its death throes have been agonizing. Two new executive producers, John Masius and John Tinker, came aboard last year to revitalize the series but only succeeded in trivializing it. Among their harebrained schemes was a continuing plot line in which a female lawyer was menaced by a knife-wielding lady loony. This went on and on until you wanted to scream, and not out of terror.

Now Masius and Tinker have been given the boot, and the final eight episodes of "L.A. Law's" season are to be produced by Steven Bochco, who co-created the series, and William Finkelstein, another "Law" veteran. They have decided wisely to jettison the soap operatics and return to the original concept of juicy or topical legal cases with some office politics thrown in.

Leland McKenzie (Richard Dysart), senior partner of McKenzie Brackman, announces as much at the start of the first of the eight shows. "I've sat by and watched as this place has changed," he grumps to fellow partners at the morning meeting. "People have dissipated their time and wasted their talent. This, ladies and gentlemen, is a law office."

Unfortunately, McKenzie's harrumph won't be enough to do the trick. By now, let's face it, "L.A. Law" has done nearly every conceivable juicy or topical case three or four times anyway, and the office shenanigans have found just about everybody hopping into the sack with everybody else. The big stars like Harry Hamlin and Susan Dey are long gone, leaving a cast of mostly second-stringers, as if this were the summer stock version of "L.A. Law."

"F.O.B.," tonight's episode, includes a plot line involving a strange young man played by Griffin Dunne, who arrives at the firm claiming to be an emissary from the Clinton administration and dropping such names as Hillary Rodham Clinton, Mickey Kantor, Donna Shalala and -- gasp! -- Barbra Streisand. Viewers are likely to see through this fellow much more quickly than the characters in the show do. In another subplot, a woman divorcing a professional boxer makes a pass at Arnie Becker (Corbin Bernsen), like we haven't all seen that a million times before.

McKenzie's speech tonight echoes one he made as the season opened in which he talked about "so many changes" in the firm but was also talking about so many changes in the show and its cast. This self-referential reflex, something that has taken some of the fun out of "Seinfeld," by the way, seems to be a way of admitting to the audience that even those who make "L.A. Law" don't much believe in it anymore.

"L.A. Law" is no longer about anything other than "L.A. Law."

"Picket Fences," on the other hand, continues to amaze, startle and provoke. Kelley grapples with The Big Issues in strikingly intimate and manageable ways, so that issue and story are almost seamlessly integrated. "Fetal Attraction," the episode airing tonight, written by Kelley, dares to deal with that touchiest of all topics, abortion. No one on the show is contemplating having one, but a brilliant neurosurgeon wants to use tissue from an aborted fetus to treat a man suffering from an advanced case of Parkinson's disease.

"This is big trouble," warns the mayor of Rome, Wis., the fictitious and microcosmic heartland town where the series is set. He could be speaking on behalf of network television, which tries to avoid the subject of abortion in non-news programs. The episode includes a scene in which a protester thrusts the bloody fetus of a dog at the neurosurgeon as he tries to have lunch at a restaurant, an entirely believable occurrence.

"It was an act of terrorism," says Jill Brock (Kathy Baker), the leading doctor in town. "We don't put up with that in Rome." The plot is complicated by the fact that Brock and the neurosurgeon were once almost married. That would have meant a more glamorous life for Brock than the one she settled for, married to Rome's sheriff.

Kelley does not make his shows preachments. Although the federal government is blasted for banning potentially lifesaving experimentation using fetal tissue (a ban the Clinton administration has lifted), the other side gets an articulate spokesman who warns of potential dangers: that use of fetal tissue could encourage women to have abortions for profit.

What you get from "Picket Fences" is not discussions or debates, however, but absorbing dramas into which the issues themselves have been absorbed. The characters are strong, the actors ideal, the sense of time and place convincing and colorful. The cast is splendid, from Baker on down through Tom Skerritt as the sheriff-husband to Fyvush Finkel as the town's seemingly only lawyer (and one's enough, don't you think?).

Ray Walston, as Judge Henry Bone, has some especially fine moments tonight, something beyond the usual blustering. The neurosurgeon is smartly played by Jamey Sheridan, who was Shannon on the still-lamented NBC series "Shannon's Deal."

All in all, "Picket Fences" is the kind of adventurous and compelling television that "L.A. Law" once was. "Well, we do things a little differently in Rome, Wisconsin," Dr. Baker says tonight, "but more times than not we get the right results."