Often, Kentucky Derby contenders compile ambiguous records during the early parts of their 3-year-old campaigns and arrive at Churchill Downs with their capabilities well concealed. But this year racing fans will not have to wait so long to know the relative merits of the best young horses in the country.

They will have to wait only until Monday afternoon, when three of the top four choices in Kentucky Derby future-book wagering compete in the Fountain of Youth Stakes at Gulfstream Park. Although this is not an especially rich or prestigious event, it is more than a mere prep race for D'Accord, Distinctive Pro and Star Gallant. The trainers have been pointing for this stake because they, like everybody else, want to know just how good their horses are and whether they are genuine Triple Crown material.

D'Accord is the morning-line favorite and the most established horse in the field, having been one of the country's top-ranked 2-year-olds last season. But the son of Secretariat actually is the least interesting of the principals in the Fountain of Youth, because the other two have such exciting, if unrealized, potential.

Distinctive Pro has displayed brilliant speed in his every race; in January he ran six furlongs in 1:08 3/5 and equaled Hialeah's track record for the distance--a feat almost unheard of for such a young horse.

Trainer Jimmy Croll and jockey Jorge Velasquez have been trying to teach Distinctive Pro to conserve some of that speed so he can go a distance.

"I've tried to slow him down with long, slow gallops," Croll said. "But Monday will tell the story. I'll either be a hero or a bum."

Lenny Imperio, the trainer of Star Gallant, may feel even a greater sense of pressure than Croll does, because he knows his horse could be not just a Derby winner but an all-time great. Everything Star Gallant has done on a race track has suggested that his potential is limitless. He has won all three of his starts impressively; whenever he works in the morning he goes extraordinarily fast. But that may be a cause for worry: Star Gallant may be a horse whose speed can't be controlled.

One astute horseman who has watched Star Gallant this winter expressed considerable doubt about his distance-going potential.

"They're training him in a very unusual manner," this observer remarked. "They train him with a pony all the time trying to get him to relax, but from my standpoint it looks as if he doesn't relax. They'll go eight or nine days just hacking him around and then the next day they'll burn up the track with him and go six furlongs in 1:10. What does that prove? It doesn't seem like the way to develop a young horse."

If the two speed horses cannot be rated, it would be easy to write the script for the Fountain of Youth:

Distinctive Pro breaks on top but Star Gallant challenges him immediately, and the horses battle head and head, running swift early fractions. Meanwhile, jockey Darrel McHargue has D'Accord sitting a few lengths behind the leaders, within perfect striking position. As they turn into the stretch, Star Gallant takes the lead from Distinctive Pro, but both colts are enervated from their suicidal battle. D'Accord rushes past them in midstretch and draws away to a victory.

Plausible as this scenario may be, I don't think it is going to materialize. Instead, I think this is what may happen in the Fountain of Youth:

The jockeys on Distinctive Pro and Star Gallant manage to restrain them for a quarter of a mile, then they begin to accelerate together. After dueling with Star Gallant for three-quarters of a mile, Distinctive Pro is practically staggering. As Star Gallant opens a clear lead turning for home, D'Accord tries to launch a rally, but all he can do is overhaul the tired Distinctive Pro. Star Gallant wins big, in near-record time.

(Thereafter, to expand upon the scenario, he goes on to win the Kentucky Derby, to be voted horse of the year and to be enshrined in the Racing Hall of Fame.)

It could happen. Star Gallant has the potential.