GENUINE RISK, almost everyone's equine girlfriend, has made watching and reading about the races of the Triple Crown this spring a genuine pleasure. Occasionally a horse comes along -- Secretariat was such a one -- that wins the admiration and respect even of those who do not follow the races around those green ovals. But rarely does one come along that wins -- even in defeat -- so much, well, affection from so many people.

What's going on? First, of course there is the fact that in a world that many feminists see as the preserve of male chauvinist pigs, Genuine Risk is a female chauvinist horse, and fillies are not supposed to run as fast or be as sturdy as colts. But Bert and Diana Firestone decided to give Genuine Risk a chance to compete with the boys in the Kentucky Derby, and she ran better than any of them, driving across the finish line right into horsedom's history books.

Then came the disaster at Pimlico. Despite the stewards and the Maryland Racing Commission, millions of Americans will probably continue to believe Genuine Risk would have won except for the coltish behavior of the California mch, Codex. Whether he bumped her or not and whether or not his jockey hit her in the face with his whip, the competition was hardly gentlemanly.

That suspicion that Genuine Risk was really the superior runner has now been reinforced by what happened last Saturday in New York. She didn't win the Belmont Stakes; some horse almost no one had heard of did. But she beat Codex, and then came the explanations. Codex, Genuine Risk's apparent chief competition for horse of the year, had been running in New York without his drugs. Stripped for the first time of his painkiller and running only on "hay, oats and water," as Genuine Risk's trainer put it, Codex wasn't equal to the job.

There are two morals to this tale. One is that something is wrong when years of selective breeding produces horses, such as Codex, who need to be drugged to perform well. The other is far more universal. It is that all the world loves an underhorse.