ELMONT, N.Y., JUNE 5 -- When trainer Jack Van Berg saddles Alysheba in a bid for glory and riches in the Belmont Stakes Saturday, he knows his main worry will be a fellow Hall-of-Fame trainer trying to make some history of his own.

Alysheba already has beaten most of his rivals in the Kentucky Derby and the Preakness, but he faces one significant new challenger for the Triple Crown in Gone West, whose trainer Woody Stephens owns one of the most amazing records in the sport. He has won the last five Belmonts, and for weeks he has been honing Gone West to be No. 6.

But much more than a niche in history is at stake when the horses go to the post at 5:33 p.m., because the 119th Belmont could be the richest horse race ever. The tracks that host the Triple Crown races are offering, for the first time, a $1 million bonus to the horse with the best overall record in the series and a total $5 million payoff to a horse who sweeps all three races. There have only been 11 Triple Crown winners; the last was Affirmed in 1978.

Alysheba has virtually locked up the $1 million bonus. (Only Bet Twice has an outside chance to take it away from him). If he wins, Alysheba will earn $3,960,300, added to his Derby and Preakness earnings of $1,039,700, to bring the total to $5 million. Little known a few weeks ago, he would instantly become the second-leading money winner in thoroughbred history.

These extraordinary circumstances have attracted more attention to this Belmont than any New York race of the 1980s. The media people here who aren't too familiar with racing may have been surprised to see how relaxed and genial the main combatants are.

Even with so much money at stake (of which the trainer gets 10 percent), Van Berg has been remarkably calm here all week -- perhaps a reflection of his confidence.

"I don't think they can beat him," he said flatly. He and Stephens have spent many hours together in front of cameras and microphones, and their mutual regard for each other -- and each other's horses -- is obvious.

"I respect Woody," Van Berg said. "He's done a tremendous job with Gone West. If I'd had him, I probably would have messed him up."

Said Stephens: "I'm going to bet the exacta both ways with Van Berg's horse after what I saw him do in the Derby. He fell down, got up again and still won."

Despite Stephens' remarkable record with Belmont horses, and stakes horses of any kind, he is likely to be the loser in this duel; Van Berg has the superior horse, and the one better suited to the demanding 1 1/2 miles of the Belmont.

Whereas Gone West has never won beyond a mile, and hasn't looked particularly strong at the end of his races, Alysheba has displayed relentless determination to win the first two legs of the Triple Crown.

The son of Alydar hardly looked so admirable in the early stages of his career. With one victory and many near misses in the first nine starts of his career, he was developing a reputation as a "sucker horse."

But after undergoing a throat operation in March, he was transformed into an aggressive competitor. He won a rough running of the Blue Grass Stakes, only to be disqualified. He almost fell when Bet Twice swerved in front of him in the Derby but recovered and rallied to win. He drew away authoritatively from the same rival in the Preakness.

"He's changed so much since the epiglottis operation," Van Berg said. "And I don't think we've seen the best of him yet."

Despite Alysheba's impressive recent victories, he has been greeted by a remarkable amount of skepticism -- partly because he never has won in New York, but largely because he won't be allowed to race with the aid of Lasix, the anti-bleeding medication that is illegal here. Instead of being an odds-on favorite for the Belmont, he was installed a tepid 8-to-5 choice in the morning line.

The second choice is trainer LeRoy Jolley's entry of Gulch and Leo Castelli. Although Gulch lost both the Preakness and the Belmont, he impressed local racing fans by beating older horses in the prestigious Metropolitan Handicap in his last start.

Gone West and his stablemate Conquistarose (who won't start unless the track is muddy) were listed at 4 to 1, with Bet Twice at 5 to 1 and Cryptoclearance at 6 to 1.

Bet Twice, second to Alysheba in the first two Triple Crown races, has a good chance to win if the favorite falters. Cryptoclearance was hindered in the Preakness when jockey Jose Santos got him bogged down on the deep inside part of the track, and Laffit Pincay Jr. will be in the irons Saturday.

The only other entrant with a remote chance is Avies Copy, winner of the 1 1/4-mile Jersey Derby who could be the front-runner in the Belmont. The others in the field are Manassa Jack and Shawklit Won.

The Belmont is part of an extraordinary day of racing here. The rest of the card includes the $200,000 Mother Goose Stakes, second leg of the "filly triple crown;" a stake pitting Groovy against King's Swan, two of the country's best sprinters; and the 3-year-old debut of Polish Navy, who looked as if he might have been the best horse of Alysheba's generation until he was sidelined by an injury last year. But these merely look like great races; the main event will be a chapter in history.