In the Fairfax Hotel, 2100 Massachusetts Ave. NW. 659-8000.

Open daily, 7 to 10 a.m., noon to 2:30 p.m., and 6 to 10:30 p.m. All major credit cards. Reservations. Prices: Main dishes at lunch $5.75 to $10.50, at dinner $9.00 to $17.50.

HOTEL dining rooms usually have a lot to live down. The Jockey Club in the Fairfax Hotel, however, has a lot to live up to. Not only was it one of the Kennedy Administration watering holes, but its kichen was the professional home of chef Claude Bouchet, and for a while it was the pacesetter for Washington's French restaurants. Over the years I have had dishes at the Jockey Club unequalled in Washington, and I have had meals left uneaten.

There are now new owners of the hotel, and management of the restaurant is in the hands of New York's 21 Club, which has refurbished the dining room and restaffed the kitchen. I thought it would be appropriate to see whether the Jockey Club was living up to or down to its past reputation.

The club wavers.

Having heard dispiriting reports, I first tried the new Jockey Club with misgiving. When I telephoned for a reservation I was answered with, "Hold the line, lady." Click. But that was followed with an apology, and when I arrived my car was met by a valet to park it. Now, valet parking, especially at lunch, is a powerful asset in a restaurant.

The hotel lobby soft and delicious; its Wedgwood blue paint is new but the opulent architectural detail remains. The Jockey Club itself is a dark, rich cave after the lobby's pastels. Fortunately, the room has been more freshened than refurbished. The elaborately carved wood panels set in niches accent the dark beamed ceiling. A treasure of Chinese porcelain is strewn from one end of the room to the other. And the banquettes -- still red leather and still set in horseshoes to carve the large room into manageable cubbies -- are ideal for seeing and being seen, allowing the diners around the perimeter to be intimately adjacent, yet publicly in view of the tables opposite.

The Jockey Club is not a restaurant where I can be anonymous; even so, I can assure you that on an unexpectedly crowded evening the kitchen can be annoyingly slow and painfully careless. And the dining room -- though the staff be highly trained and suave, adept at tableside flourishes and knowledgeable about the preparation of the food -- can be swamped by too much to be done by too few. One Sunday a single captain and busboy scrambled to serve seven tables, most of them requiring tableside carving of racks of lamb. Yet, fully staffed, with the reservations properly paced, the choreography can be graceful, and one can appreciate the precise pacing of the meal, the luxurious touches like telephones brought to the table on request, the Godiva mints to finish the meal.

The one certainty about a meal at the Jockey Culb is that it will be very expensive. In the grand hotel dining room tradition, its prices are pure outrage. The Jockey Club serves what (I hope) is the only $9.50 hamburger in town. Its soups average over $3. Among dinner main dishes, the cheapest is chicken hash with wild rice at $9. Don't expect to spend less than $30 a person if you drink any wine at all -- a decent bottle will cost at least $15 to $20, and a single glass (a rather nice burgundy is the house white) costs $2.50 Even lunch will cost $20 to $25 a person with tax and tip.

Washingtonians, for some reason, appear undaunted by expensive menus. And the Jockey Club has been heavily populated on each of my three recent visits. It was worth the money once or twice. But at those prices I expect more certainty.

My first meal, to be more specific, was a pleasant surprise. Mushrooms a la Daum are a 21 Club recipe, a heady concoction of julienned ham and tongue with sliced mushrooms in a brown sauce. A hearty beginning, and more successful than the oysters Rockefeller, which are appealingly undercooked but sandy under their strong green anise-scented herb paste. Main dishes were exceptional -- a veal as pale as cream, in a cream rich and smooth and fragrant with wine, a fricassee of uncommon quality except for its acid canned onions. The fish, a grilled red snapper, was fresh and juich and crusty on its surface, with a soft and lovely sauce choron. Vegetables -- in this case broccoli with riced egg -- were not a strong point. As for dessert, my several visits reiterated that the fruit tarts are better than Washington's average but barely. Napoleons tasted as if they had met their Waterloo. Puddings were excellent, the chocolate pot of creme densely creamy, a nice change from chocolate mousse, and the rice pudding a glorious rendition except that the rice itself was a problem: "Is it the French way not to cook the rice?" queried a guest. But the single most compelling reason for dining at the Jockey Club is the cheesecake -- the weightiest, smoothest, purest of cheesecakes, with strata of chocolate and an authentic cake crust. 21 Club knows its cheesecake.

Now that you know the best of the Jockey Club, I'll expose you to its worst. Keeping in mind that the staff recognized me as a restaurant critic, wonder along with me why me calf's liver, ordered rare, was thoroughly overcooked, dry, bordering on bitter, and chewy with untrimmed veins.The french fries, on the other hand, were pale from undercooking. I wonder, as well, why my rare hamburger -- that extraordinarily expensive ground meat patty -- was brown straight through, yet hardly crisped on the surface. In any case, I think, the chopped sirloin is not improved by mixing with bread crumbs and ground celery, and its red mustard sauce would have been its savior if it could have been redeemed.

The series of ups and downs at the Jockey Club ran thus: smooth, delicate duck liver pate beautifully decorated; a creamy chicken hash that elders on a bland diet would swoon over; and bright crisp green beans. At the same meal, however, bouillabaisse was of shallow flavor and stingy servings of crustaceans (one lobster claw, one mussel, one clam, one shrimp and a lot of fish). Duck with green peppercorns, at another meal, was cooked to a most attractive crispness and bathed in a sharp flavored but light textured peppercorn sauce.And clam chowder was distinctive, even with its chewy clams. But then there was veal francaise cooked to a lifeless, stiff state, then oversalted, its sauce breaking into pools of butter. Even the zucchini was overcooked and waterlogged. There were other dishes of quality -- Jockey salad, crab Jockey, smoked trout -- and there was a delicately poached salmon in a sauce venetienne. But the sauce was gritty with excessive dried tarragon and diluted by insufficient draining of the fish. What is more, the same dish served to another table had a bright green sauce that looked totally different from ours.

Trying to generalize, it seems that the dishes which are made ahead -- pate, veal fricassee, chicken hash, cheesecake, puddings -- are particularly good. Fish is cooked with care, at least if you are a visiting restaurant critic. Sauces are light and fragile. But seasonings are often awry with too much salt or too many herbs. And grilling of meats is sloppy at best. At such prices one is paying for distinction, and the Jockey Club is not yet nearing the head of the class.