Tim Zagat, publisher and co-creator of the Zagat Restaurant Survey, is dashing about on one of his frenetic monthly restaurant tours. "There are some places," he says, exiting a seedy spot in downtown Manhattan, "where the minute you smell them, you know you don't want to go back in again. This place smells like cleaning fluid." Tonight's tour has Zagat and a small entourage careening through the maze of narrow streets near the financial district in his 11-year-old Toyota wagon. Searching for snappy new eateries to add to his annual listing, he allots about three minutes to size up the decor, menu and crowd at each place, while totally ignoring the food. Critiquing the cuisine will come later, when Zagat's army of eaters descends to render a collective thumbs-up or down.

Zagat is one restaurant critic who doesn't sample dishes; he samples opinions. Each one of his pocket-size, cranberry-colored guides is a distillation of the ratings of thousands of volunteer lay gourmets, who send in comments on as many Chez Babbettes and Vito's Trattorias as they and their budgets can bear. In the often elitist world of food criticism, that democratic approach has proved a stunning success. As recently as 1979 Tim, 47, and wife Nina, 44, were mimeographing their restaurant surveys. They published their first major restaurant guide in New York in 1983, then moved on to Chicago, San Francisco and Washington, D.C. Their first L.A. guide, published in December, sold out in six weeks; next year they'll add Boston and New Orleans. Their latest New York City guide, out last November, was a paperback best-seller by January and is now in its fourth printing.

Based on questionaires sent to 8,000 food fanatics in the cities they cover, the Zagat guides rate individual restaurants on food, decor, service and cost ("before drinks and tip"). Brief four-to-five-line reviews hit the high and low points of each entry. "Basically the participants are looking for something good, but no critic has ever bombed a place the way our people have bombed some restaurants," says Tim, who relishes picking his contributors' most piquant remarks. One irreverent Zagatnik called Sardi's, the legendary aprestheater haunt, "the longest running gag on Broadway." Mortimer's, a hangout for the city's society set these days, was deemed a "con game," and "better for people-watching than dining...."

Despite the sometimes ruthless reviews, the Zagat guides have earned praise from food critics and connoisseurs. Andre Soltner, owner of New York's Lutèce—the Zagatniks' contender for the title of America's best French restaurant—says, "The idea is great. If you have the opinions of many, it's a little more fair." Jay Jacobs, until recently restaurant reviewer for Gourmet magazine, calls the guides "the most dependable cross section I've seen. The contributors are putting their money where their mouths are."

The Zagats' reviewers do that with gusto. New York alone had more than 2,200 consumer-contributors last year, and most review about 40 restaurants, though one insatiable critic rated 250. Nor is the everyman concept the guides' only distinction. Each carries a specialized index that groups restaurants in such categories as People Watching, Power Scenes, Wheelchair Access and Prix Fixe Menus. The guides now are so time-consuming—and profitable: In the last 18 months they have grossed more than $1 million—that Tim quit his post as chief litigation counsel at Gulf & Western and maintains only a small private practice.

That kind of success simmered a long time before boiling. The Zagats met in 1963 during their first year at Yale Law School. She was fresh out of Vassar, he had graduated from Harvard two years earlier. "We started studying together and the next thing I knew, I was studying all the time," says Tim. Her cooking helped—at least at the time. Though they eventually got tired of Nina's Polynesian Chicken(spiced with "pineapple and God knows what else," says Nina), the dish was a kind of recreational therapy. "It was a really nice break to make something and then two hours later find out if it was a success or not," Nina recalls. "Everything else in law school goes on for the whole term."

The two married in 1965 and, after graduation, moved to New York, where they both found work lawyering. A year later Tim's firm offered him a job in Paris, and Nina arranged for a transfer. They moved to on the Left Bank, and Nina began spending her lunch hours taking cooking lessons at the Cordon Bleu. In no time the couple, with a small group of friends, began exploring la belle cuisine. "You'd have to be an idiot to be living in Paris and not try all the restaurants," says Nina. Soon they were comparing their ratings with those of the established guides. "It was a major research project," she says.

The Zagats returned to New York in 1970. "It was a big change," says Nina. "There weren't any of those wonderful restaurant books we used to pull out in Paris." So they put together a mimeographed survey in 1979 by asking 150 friends and acquaintances to rate 75 well-known local restaurants. "People asked for more copies and kept handing them out to their friends," says Tim. "By the third year we were dealing with 350 restaurants." Then they published their first general market guide—and found themselves with a best-seller. "What was once a hobby," says Tim, "turned into an enterprise."

Nina, besides being a partner in the couple's publishing business, still practices law at Shearman & Sterling in Manhattan. Last year, as the attorney who drew up the final series of wills for the late J. Seward Johnson, she came under fire during that notorious will trial for allegedly conspiring to make Mrs. Johnson sole heir to the $500 million pharmaceutical estate. Zagat wound up with $1.8 million in commissions and fees. Such fees represent a nice garnish on their profit from the guides. "I never expected the response and success we've had," says Tim. "I still don't know what we did right." Nina does: "We just did something that interested us and other people we knew. Wouldn't it be funny if, in a business school class ten years from now, some professor said this was an example of how to start a business?"