Even in the years when it has attracted subpar fields, the Kentucky Derby always has seemed special, charged with excitement and emotion and importance. But the Derby week that culminated with Gato del Sol's upset victory was more farce than drama. And what happened at Churchill Downs this week raises some troubling questions about America's greatest horse race.

The 108th Derby was, of course, marred by the ailments that took Timely Writer and Hostage out of the race. Their ill fortune will prompt some people to raise the old objection that it is premature to ask 3-year-olds to run 1 1/4 miles on the first Saturday in May, and that too many horses break down being trained to do so. But the attrition rate for races held later in the season probably would be even greater. Besides, history has proved that the Derby is a true championship event. Great horses win it more often than any other race in America (even the purists' beloved Belmont Stakes).

The Derby, however, is not an "official" championship event in the sense that the Super Bowl is. It has become a great race and a great institution because horsemen have chosen to make it so. Like most venerable institutions, it deserves to be treated with respect.

When Henry Clark, the trainer of Linkage, chose not to run his horse at Churchill Downs, he was tacitly saying that he didn't attach much importance to the Derby. It was as if Jack Nicklaus had said he wasn't coming to the Masters because he wanted to prepare for the Kemper Open instead. It deflated an event whose importance lies in its universal acceptance as the championship event.

But if Clark showed little respect for the Derby, some of the trainers who did come to Churchill Downs showed even less, by bringing horses here who clearly did not belong in the field.

Of course, the Derby always has attracted its share of kooks and dreamers who have lent it a special charm. Who could criticize ailing J.E. Jumonville for buying Real Dare for $750,000, so he could watch television from his sickbed and see the gelding carry his colors to a 19th-place finish?

But Saturday's field was full of colts who were owned and trained by experienced professionals who should have known better. Eugene Jacobs, the veteran New York horseman, talked with a straight face about entering an allowance horse named Cut Away to "set up the race" for New Discovery, who had lost his last start by 25 lengths. New Discovery finished 18th.

John Greathorse, scion of a prominent family of Kentucky breeders, acknowledged that to run an inexperienced colt like Wavering Monarch in the Derby probably would be stupid and destructive--then did it anyway. Wavering Monarch finished 12th.

Most of the trainers spent most of the week offering spurious explanations of their horses' bad races, and constructing rationalizations for their presence in the Derby field. There is more intelligent horse talk in the Pimlico grandstand than there was on the Churchill Downs backstetch this week.

Part of the reason for the influx of bad horses is the Daily Racing Form's straight-faced reporting of "Derby Doings," which seems to legitimize any four-legged creature whose trainer is thinking of the Derby. Part of the reason, ironically, may be Churchill Downs' new rule limiting the field to the 20 entrants with the most career earnings. Now the people with a moderately talented horse who happens to rank 19th on the list start to think that legitimizes him as a contender. And part of the reason for the swelling fields seems to be that trainers have lost any sense of shame or embarrassment about bringing a bad horse to this great race.

The trend is established. From 1930 to 1980 there were only five 20-horse fields, but the Derby had 22 entrants last year and 20 this year (with one scratch from each). These oversized fields change the character of the race. In a 20-horse cavalry charge, it is impossible to assume that the race will be truly run and the best horse will win. I always had assumed that ponderous stretch-runners would be hurt most by the traffic congestion, making it very difficult to pick a horse like Gato del Sol, but the effect of the large fields this year and last has been somewhat different.

When there are 20 horses in a race, a number of them will be speed horses, or else horses whose owners want to see them in contention for a little while. In the last two Derbies, the pace has been sufficiently fast that it has helped eliminate all the speed horses. Saturday, Gato del Sol, Laser Light, Reinvested and Water Bank were running 16-14-13-12 after three-quarters of a mile, and finished 1-2-3-4.

This result confirmed the thinking of some of the trainers who brought mediocre horses to the Derby. As the roster of Derby candidates grew during the last week, more and more trainers started thinking that, in a 20-horse race, anything could happen. They might get lucky. They might as well take a shot.

Indeed, the results of the 108th Kentucky Derby bore little relation to the prior records of the horses. Gato del Sol had not won a race as a 3-year-old. Neither had Laser Light. The credentials of Reinvested and Water Bank were even shakier. It was hardly the kind of result that confirms the Kentucky Derby as America's great championship horse race.