Racing fans in Florida this winter got to witness an extraordinarily rare phenomenon. A jockey was performing so brilliantly that he distorted the normal handicapping process, and seemed to transform the horses he rode.

New Yorkers agreed that they had seen such a thing happen only once before, when Steve Cauthen burst onto the racing scene and won races with horses who had no right to win. Now the great Angel Cordero Jr. was doing it, giving the ultimate exhibition of his formidable skills.

But there was a sad contrast between Cordero's streak and Cauthen's. In 1978 Cauthen was a fresh-faced youngster whose success promised to be just the start of a wondrous career. But as Cordero rides, observes speculate regularly about how close his career may be to an ignominious end.

Cordero rides each day with a sword hanging over his head, the threat of an indictment for race-fixing. Last month ABC televised an interview with his accuser, the confessed race fixer Tony Ciulla, who repeated his charges against Cordero.

Oddly, the simmering charges seem to have had a positive effect on Cordero's performance. "Angel is riding better than I've ever seen him," said trainer Steve DiMauro, who has watched and admired the jockey for years.

One cynical horseplayer at Gulfstream Park offered a theory to explain Cordero's excellence:

"He riding to beef up his defense fund." Another horseplayer corrected him: "No, he's riding to establish his defense." With his exceptional performance, Cordero is posing the question: could a jockey who wins so many races be conspiring to lose them?

Whatever his motivation, Cordero's results this winter were unambiguous. They buttressed ny conviction that in spite of the accolades that riders like Bill Shoemaker, Laffit Pancay Jr. and Cauthen may get, Angel Cordero Jr. ranks in a class by himself among American riders.

I am not ordinarily a jockey-lover. Even the best of them perform an essentially negative function. Their job is to avoid getting their horse blocked or bumped or otherwise hampering the mount.

Because jockeys don't do anything very interesting, their admirers have to invent explanations for their success. Thus, the young Cauthen was supposed to possess some magical affinity with the horses he rode. Shoemaker is supposed to have hands to which horses respond especially well.

I've always thought that these explanations are so much horse manure. At least, I can find no evidence to support the theory that thoroughbreds perform with more motivation for certain riders. But when Cordero is playing his skills, he often does things that I can see and appreciate. And they are things that I rarely see other riders do.

As a handicapper, I know that one of the crucial factors in racing is the bias of the track: the tendency of a racing surface to favor front-runners or stretch runners, horses on the rail or on the outside. Most trainers and jockeys are utterly oblivious to this factor; Cordero understands.

In the Donn Handicap at Gulfstream, Cordero was riding an outsider named Addison, who didn't have a chance to beat the favorite and who figured to be no factor whatsoever because of the track conditions.

The Gulfstream track favored horses on the inside, and Addition was breaking from the outside post position. Moreover, there were speedsters inside him who would prevent him from outrunning the field and dropping over to the rail. I confidently put a big X through his name in my Racing Form.

But Cordero was thinking the same way. Knowing that his only chance was to get to the rail, he started warming up Addison with incredible vigor, as if he were getting ready for a 3 1/2-furlong dash at Shenandoah Downs rather than a 1 1/8-mile route.

And when the gate opened, Cordero came gunning from his outside post position as if he were a madman -- or an overeager apprentice. But with Cordero pumping, Addison outran the other speed horses, got to the rail and managed to finish second in a $75,000 stake when logic decreed he shouldn't have been close.

Cordero would always tailor his or his horse's style to the prevailing conditions. At Hialeah, the inside part of the track was either favorable or neutral on 43 of 44 racing days. But on that other day, the rail became deep, although this was not obvious and was perceived by most horseplayers only with the benefit of hindsight.

In one of the early races that day, Cordero was sitting in fourth place behind three deuling leaders, and had a chance to drive up inside them. Yet on this day he yanked his horse to the outside and circled the leaders, a move he would have considered foolish on any of 43 other days.

If another jockey had made similarly shrewd decisions and moves, knowledgeable horseplayers would have been buzzing about them. But after Cordero had been riding in Florida for two months, people hardly bothered to comment. His brilliance had become a matter of routine.