Trainers who deal mostly with cheap, infirm thoroughbreds always dream of getting the "big horse," a bona fide top-class runner. If they let their imagination run wild, they might even dream of managing a contender for the Kentucky Derby.

King Leatherbury, Maryland's master wheeler-dealer with claiming horses, might have such a horse in his barn now, the undefeated 3-year-old I Am The Game. But Leatherbury seems uneasy, almost embarrassed, about the local ballyhoo for his colt.

"It's more fun training claimers," he said yesterday.

I Am the Game represents, in many ways, a great departure from Leatherbury's usual modus operandi. He has never claimed, or aspired, to be a "horseman" -- the type of trainer who personally works on the legs and knees and ankles of his charges.

Leatherbury delegates those tasks, while he operates more as a business manager, planning what claims he will make and where he will run the members of his large stable. He spends more time in his office than in his horses' stalls, and if that approach may offend some purists, there is nobody in America who plays the claiming game more shrewdly than Leatherbury.

So it was rather surprising when a yearling son of Lord Gaylord was sold for $255,000 at Saratoga last summer and the buyer was listed as King T. Leatherbury. What did he have in mind?

Leatherbury is a student of breeding, and he said, "What got me interested was Lord Gaylord. Not many people know him, but statistically he raises your eyebrows; he has a very high percentage of stakes horses. The dam of the yearling, Kitchen Window, was one of the two best mares he's ever been bred to. When I looked at the catalogue, I had no thought of paying a lot of money, but when I was bidding over the telephone I got carried away. After $200,000, what the heck is $220,000?"

When I Am the Game started training, Leatherbury said, "It was obvious he had a lot of ability. He had a really nice way of going." What caught the attention of people on the backstretch, even more than the horse, was the effect on Leatherbury. He would sometimes take the colt's reins and lead him to the track for a workout -- unprecedented behavior for this remote-control trainer.

Leatherbury sent I Am the Game to New York for his racing debut, and the colt won an Aqueduct maiden race by four lengths. Then he came back home and took the W.P. Burch Stakes at Laurel by a length. But neither race was impressively fast, and Leatherbury knew it, even if the rest of the world didn't.

"It's really turned me off the way the hype has come for this horse from I don't know where," he said. "When he broke his maiden, I read one headline about 'Leatherbury's Derby Horse.' That's ridiculous! So my policy has been not to talk too much . . . . A horse's performance should do the talking."

On Feb. 3, in the Francis Scott Key Stakes at Laurel, I Am the Game spoke eloquently. He drew away to win by 5 1/2 lengths, and his time finally impressed speed handicappers. This was no hype; this was a legitimate top performance, and Leatherbury knew it.

Next Monday I Am the Game will get his most serious test when he runs in the General George Stakes against formidable, undefeated Roo Art. If he wins that one-mile race, Leatherbury will have to start mapping out a possible route to the 3-year-old classics.

If that happens, Leatherbury will be playing for the highest stakes of his training career, and playing a completely new game. But nobody who has watched him play the claiming game so brilliantly for so many years can doubt that he'll be able to make the transition. He might disregard some of the obligatory hype that is part of the 3-year-old classics, but if I Am the Game proves to be a good enough horse, Leatherbury will know how to manage him.