A NEW BOOK called Bordeaux, by Robert Parker, has appeared to challenge the preeminence of Michael Broadbent's classic The Great Vintage Wine Book and is an indication of how far wine appreciation has come in a few years. Bordeaux (Simon and Schuster) lacks the elegant feel, and the prose, of the more general Great Vintage Wine Book but makes up for that in energy, focus and sheer weight of fact.

Broadbent began to write about wine when its appreciation was limited to nobility and the similarly disposed; since then, wine has become a thoroughly middle-class preoccupation, with some consumers wanting the same concrete advice that is available for cars and washing machines.

Parker writes for today's audience, with lots of numbers as handles on an elusve product. The subtitle is "The Definitive Guide for the Wines Produced Since 1961." Whether or not that is so, Bordeaux is full of information about one of the world's most famous wine regions. Parker is a local phenomenon, a Baltimore attorney who began drinking wine during a visit to Alsace, where he discovered that it was cheaper and better than Coca-Cola. He turned that discovery into a new career with a successful wine-buying guide, The

Wine Advocate, and an international reputation that has a big impact on wine sales.

The book does not lack for opinion on old

and new wines. Bordeaux is more difficult to

use than Broadbent's book, being divided up

geographically rather than by vintage, but it is

a valuable contemporary guide. Parker's enthusiasm for his subject sometimes outruns his

store of superlatives. For instance, after words

like "astonishing" and "legendary" are used to

describe several wines they lose some of their

imaginative power. Parker's palate, however, is

quite sound.

Parker's 100-point rating system should be

viewed with some skepticism. The scale,

widely copied, is really based on 40 points, since nothing below 60 is worth consideration, according to Parker. In effect, it is closer to a 10-point scale, since most people who use it as a guide buy wines rated in the 80s. The 90s are stratospheric and rarely attained, and the 70s are not considered very desirable. The difference between an 84 rating, say, and an 86 can influence sales and opinion when in fact there is a minuscule difference in quality. The method for making such fine distinctions is unclear.

Another problem is the rating of wine according to drinkability and potential, two different categories that would seem to demand two different scales in such a rigorous rating system. There are many 1982 wines rated in the 90s on Parker's scale, for instance, that are currently undrinkable, and many wines of good vintage and great drinkability rated below the '82 bordeaux. That is confusing at best.

The impression of absolutely measurable quality in wine is generally misleading. Evaluation is a highly subjective matter. Ideally, you open a bottle of bordeaux and say to your dinner partner, "This is a magnificent St-Est,ephe, and I love you madly." You don't say, "This is an 89, and possibly a 91."

Because wine is an ineffable product in a quantifiable age, it has special value. By its very nature it is mysterious. Once you start seeing numbers instead of visions when you drink it, you are lost to its charm.