The vision that comes to horse players eager to beat the odds-on choice in the Belmont Stakes is that of a fatigued favorite being caught in the late stretch by some sturdy steed showing a greater liking for the whole 1 1/2 miles.

For that breed of bettor, that's the ticket for beating the unbeaten Seattle Slew Saturday, so those visionaries will go for the stretch runners, Sanhedrin, Run Dusty Run and Iron Constitution, who lost to Slew over a lesser distance but were gaining in the stretch.

Alas, Seattle Slew, in the frontrunning manner that has been his mark, will probably lick them again. More horse players have died broke betting on stretch runners than on any other types. There is even a famous epitaph for a confirmed stretch runner who saved his breath in the early running: "Often late, often."

Those horses that lollygag in the early running and then make a good showing later are remindful of what an umpire once said to Jimmy Dykes who tried to avoid a tag at second base by zagging into short center field. He was obviously out for running out of the base path, but Dykes circled back and dove into the bag. When called out, he screamed to the umpire. "He never touched me." The umpire said, "That's right, James, but where have you been meanwhile."

Because the Belmont is the longest, by a quarter of a mile, of the Triple Crown races, there is a persistent notion that it favors come-from-behind runners. But this is defiance of one statistic that shows 31 of the last 40 winners of the Belmont were in front an eighth of a mile from home. Eight of the other nine were within a half length of the lead at the point.

At least one of the top 3-year-olds has conceded the Belmont to Seattle Slew. This is Cormorant, which ran head and head with Slew for the first mile of the Preakness but couldn't keep it up. His owners are skeedadling off to Ohio for the $150,000 Ohio Derby June 19, where Seattle Slew will not be on that date.

"Jim Simpson, Cormorant's trainer, doesn't need a guardian. It makes no difference to him where he makes his money. "This was the comment of Humphrey Finney, the sage of Lexington and head of Fasig-Tripton Sales that turned up Seattle Slew as a $17,500 purchase in 1974. "Is there anything that can run with Seattle Slew? Finney asked in a tone that answered his own question.

Of Sanhedrin, Finney said, "He's got a solid pedigree but I wouldn't say he's in Seattle Slew's class. He's leggy and light-framed and hasn't got eye appeal." He added, however, that the great Kelso wasn't much of a looker, either: "A big ugly, but after the entered the winner's circle for the 25th time he began to develop eye appeal."

Lou Rondinello, Sanhedrin's trainer, has lately been speculating his colt would be the one to catch Seattle Slew in the stretch. He has already had three shots at Slew, finishing 14 lengths behind him as a 2-year-old, 3 1/2 lengths back in the Wood Memorial and only two lengths back with his stretch rush in the Derby. "Maybe we'll make it this time," Rondinello said. "If the Slew puts in a real fast first mile, it's not going to take a hell of arun to get past him."

The admiration for Seattle Slew has been growing since he added the Preakness to his Derby triumph. Leroy Jolley noted Slew's gameness in winning the Derby after he was sloughed at the start. He bulled his way into an early lead, put in a sizzling first mile and stayed in front. "He had seven ways to lose that Derby," said Jolley, "and he didn't take any of them."

For Seattle Slew, the dollar signs are all over the oval 1 1/2 miles of race track here. His syndication price, already reckoned at $10 million, would go up an estimated $2 1/2 million more in the approximate 2 1/2 minutes it should take him to win Saturday.

This reevaluation of Slew as a stud would be in admiration of his splendor as history's only undefeated Triple Crown champion. Calculate it another way and Slew's earnings Saturday would break down to a million dollars a minute. Equally fascinating would be the return to his owners on a distance-raced basis, a whopping $1,666,000 per mile.

Eat your hearts out, Hertz and Avis.

But all of this is premised on no shocking comeuppance for Slew Saturday in the race he dominates today as a 1-5 prepost favorite. Suddenly the field has swelled from five to nine challengers. Most of their owners are conceding $110,000 first money to Slew and are sniffing eagerly at the $40,436 for second place and the $22,056 for third. Neither does the fourth money of $11,028 provoke a sneer.