Even Woody Stephens, who trains the Belmont Stakes contender Caveat, could not suppress an honest assessment of the horses in Saturday's race: "None of 'em are much."

Enough other owners and trainers feel the same way about the current crop of 3-year-olds that a record 15 horses have been entered in the 115th running of this classic (WDVM-TV-9, starting at 4:30 p.m.). Most of them are here because they hope they might get lucky in a wide-open race.

But the people who manage one of these horses dispute the prevailing viewpoint. They think there is one potentially ouststanding colt in this field, and that his quality will become manifest at about 5:40 p.m.

"If Slew O'Gold runs his race, I don't see how any horse can beat him," said the colt's co-owner, Mickey Taylor. His partner, Jim Hill, concurred: "I don't know how we could be in a better position."

Many bettors will agree with their assessment, and they will probably make Slew O'Gold the clear favorite over Caveat, High Honors and Preakness winner Deputed Testamony. The support for Slew O'Gold is based not so much on his overall record as on the perception that he has been improving steadily and is just now reaching his peak.

Taylor and Hill knew that Slew O'Gold did not have quite enough seasoning when they took him to Churchill Downs last month, where he finished fourth in the Kentucky Derby. But since then, he has been impressive in everything he has done.

Jockey Angel Cordero Jr. rode him in his first workout after the Derby, and when he dismounted, he exclaimed, "Hey! This horse is changing." Slew O'Gold confirmed that opinion in the Peter Pan Stakes here two weeks ago when he ran away to a 12-length victory, covering 1 1/8 miles in 1:46 4/5. "When we turned for home," Cordero said, "he just kept going without any urging. He's the best he's ever been. He's got everything going for him."

One of the things Slew O'Gold has going for him in a 1 1/2-mile race is his breeding. His sire, Seattle Slew, won the Belmont in 1977; his dam, Alluvial, produced the 1979 winner, Coastal. On the basis of pedigree, Deputed Testamony shouldn't be allowed on the same track with him. But Slew O'Gold may get his most serious competition from the humbly bred colt from Maryland.

Deputed Testamony has been a forgotten horse here this week. He is quoted at an almost insulting 8 to 1 in the morning line. This price is the result of New Yorkers' opinion that his Preakness victory--which he scored by sneaking through on the rail over a sloppy track--was something of a fluke.

But Marylanders who have followed the colt's storybook career, which began in $25,000 claiming races, know he does not need everything to go his way. In the Federico Tesio Stakes at Pimlico, he swooped around the field to score an impressive victory over Dixieland Band, who subsequently won the Pennsylvania Derby and is now entered in the Belmont, too. Deputed Testamony is genuine.

At least five other horses in the field can be considered legitimate contenders. Caveat will be the second choice in the wagering on the basis of his third-place finish in the Kentucky Derby. High Honors rallied strongly through the stretch in the Preakness. Current Hope won the Flamingo Stakes at Hialeah and since then has continually encountered sloppy tracks, which he detests.

Megaturn impressed New Yorkers with his powerful finishes before he gave a disappointing performance in the Florida Derby. Barberstown has come from California with a three-for-three career record, although he is almost certainly not seasoned enough to win the Belmont.

Slew O'Gold's people are undaunted by the hopes of all the challengers. They think their colt is about to change the popular perception of this whole generation. "Look at Conquistador Cielo," Cordero said, recalling last year's Belmont winner. "A month before the Belmont, he was just another horse, but when he reached his peak he went from a horse to a superstar. That's what's going to happen to my horse."