In 1982, 1981 and 1980, racing fans moaned about the low quality of 3-year-old racehorses in this country. But those undeniably subpar years are beginning to look like the good old days.

With the 1983 Kentucky Derby less than a month away, not a single colt has displayed exceptional talent or captured the public's imagination. The prominent Derby candidates haven't even been consistent in their mediocrity. Desert Wine was considered the best of the lot, but Sunday ran dreadfully at Santa Anita. Pax in Bello inherited the role of Derby favorite but promptly lost a minor race for Florida-breds at Hialeah yesterday.

The scarcity of outstanding U.S. horses in recent years is a perplexing phenomenon, since the thoroughbred industry is supposed to be "improving the breed." Indeed, scientific breeding procedures enable top stallions to beget more offspring than in the past. Computers are used to analyze the records of stallions and mares and suggest ideal matings. With great stallions like Northern Dancer, Nijinsky, Roberto and Seattle Slew, the U.S. breeding industry has never been stronger.

So why isn't it producing more great horses?

To some extent, racing fans were spoiled, and their expectations were raised too high, in the 1970s, a period that has been dubbed the "decade of champions." Anybody compiling a list of the best racehorses of all time would have to include Secretariat, Forego, Affirmed, Seattle Slew and Spectacular Bid--all of whom were born between 1970 and 1976. Probably never in the history of the sport have so many great horses come to prominence in such a short period of time. That was a statistical fluke. But the current dearth of equine stars is more than a statistical fluke.

The quality of U.S. racing has declined because the best horses bred in this country are being bought by foreigners and are racing in Europe.

The current generation of 3-year-olds were yearlings in 1981, which happened to be the year when Arabs started becoming seriously involved in the thoroughbred game. Competing with Briton Robert Sangster for the prime U.S. bloodstock, they drove yearling prices up to astonishing levels, which even the richest U.S. buyers could not afford. In 1981, a total of 13 yearlings sold for $1 million or more, and only two of them stayed in this country. One, Chumming, is a well-regarded Kentucky Derby contender. But there are remarkably few colts with true classic breeding among this Derby's candidates.

It was at the 1981 sales, too, when foreigners started moving more aggressively into the second tier of the U.S. yearling market. Once they had been interested only in the high-priced offspring of great stallions like Northern Dancer and Nijinsky; now they were buying $100,000 yearlings, too. A colt named Dunbeath who sold for that price is the favorite for the Epsom Derby.

"There's no doubt that the Europeans have skimmed off the cream of this crop," said Bill Oppenheim, editor of the industry newsletter Racing Update. "Last year, they were saying that their 2-year-old crop was the strongest in the last 10 or 15 years. And at least 50 percent of the horses in their upper echelon were American-bred. I think that (English trainer) Henry Cecil could take his fifth-best 3-year-old and win the Kentucky Derby."

European competition is likely to remain strong for the next couple of years, at least. Foreign buyers continued to dominate the yearling sales in 1982, taking abroad the best-bred U.S. horses and reducing the likelihood that another Secretariat, another Seattle Slew or another Spectacular Bid is about to appear here.