From now until Saturday, an army of media people will be tromping through the Churchill Downs stable area, chronicling every move of every Kentucky Derby candidate. If a prominent 3-year-old sneezes this week, the world will know it.

This week of overkill is, in fact, the culmination of months of overkill. All through the winter and spring, journalists have examined every race for 3-year-olds for its possible Derby implications. In February, The Washington Post devoted extensive coverage to an allowance race at Hialeah because it was a prep race for a prep race for the Derby.

It could be argued that all this attention to the Kentucky Derby is grossly disproportionate, especially since the major stakes at Belmont Park in the fall have become America's true championship events. Nevertheless, I would argue that all this coverage of the Derby is valuable, especially to horseplayers who want to learn more about the nature of the sport and the techniques of handicapping.

If Wordsworth could perceive the nature of the cosmos by staring at a daffodil, we surely can learn valuable lessons about handicapping by studying one race intensively. The Derby has a way of teaching these lessons in a vivid and memorable fashion.

Before last year, I had always doubted the importance of pace; I did not believe that even unusually fast early fractions could determine the outcome of a race. But the first quarter of the 1981 Derby was so devastatingly fast that the horses who were running 1-2-3-4-5 finished 19-10-18-16-17. The first nine finishers were all stretch runners and, in some cases, mediocre plodders trounced capable speed horses by 10 or 20 lengths. It was impossible to ignore the conclusion that pace had affected every horse's performance. Perhaps I could have learned the same lesson from some claiming race at Laurel, but such races are easily forgotten. The Derby is not.

In the 1974 Derby, I first began to perceive the importance of what is now called trip handicapping. With 23 horses in the field, the outcome was determined by the way the race developed--by which horses had good trips and which had bad trips.

Cannonade won by saving ground on the rail; Hudson County, a very mediocre animal, finished second by racing on the lead and thus avoiding any traffic troubles. The best horse in the field, Little Current, encountered much trouble and finished fifth. It was a revelation to a devoted speed handicapper to know that there are races where figures mean nothing; class means nothing; trips mean everything.

The Derby offers handicappers a unique learning opportunity, because it is the one race of the year in which outsiders can acquire all the information they want about all the horses. Ordinarily, we study the past performances in the Daily Racing Form while realizing there are many things we cannot know: Has the favorite run a fever since his last start? Did the exercise boy mess up his last workout? Large numbers of horseplayers think that beating the races is impossible without access to such inside information.

In fact, a week of intensive exposure to this inside stuff is enough to reveal how useless it can be. Trainers and owners are notoriously unobjective, and what they perceive as inside information is often just rationalization.

At the start of the 1973 Derby, Sham hit his head against the side of the gate and knocked two teeth loose. He lost to Secretariat by 2 1/2 lengths, and trainer Frank Martin confided that this incident had made the difference. Two weeks later, after a trip to the dentist, Sham came back in the Preakness and lost by precisely 2 1/2 lengths again.

The only category of information that is always valuable is an admission by a trainer that his horse's physical condition has deteriorated since his last race. When a trainer says (as Buster Millerick did before saddling the colt George Lewis in 1970), "We may have to put him in a wheelchair and push him to the starting gate," that's a pretty persuasive knock.

But in 13 years of patrolling the Churchill Downs backstretch, I have never acquired information that helped me pick the Derby winner, and in a couple of cases access to insiders helped throw me off. LeRoy Jolley, one of the most astute and analytical of trainers, persuaded me to ignore Honest Pleasure's mediocre performance in his final prep race before the 1976 Derby. I shouldn't have. And Jolley himself had so many doubts about Genuine Risk in 1980 that it was hard to take her seriously as a Derby contender. I should have.

There is no substitute for clear-eyed, objective study of any horse race. While horseplayers may sometimes think (especially during the throes of losing streaks) that trying to predict the performance of a bunch of dumb animals is an exercise in futility, the history of the Derby proves otherwise.

When the Derby is over, when we have scrutinized everything that has happened, the outcome almost always makes sense--the lone exception being Canonero II's unforeseeable victory in 1971. Otherwise, the race has always verified that the game is beatable.

Even after supposed upsets, the results prove to have been determined by logical, rational factors--if only we'd been smart enough to perceive them beforehand.