When Charismatic tries to complete a sweep of the Triple Crown races in Saturday's Belmont Stakes, he will be attempting a feat that has eluded the great and the near-great. In six years since 1978, a colt captured both the Kentucky Derby and the Preakness, came to Belmont Park amid great acclaim and was favored to capture the 1 1/2 -mile race. Each time he was foiled.

What makes the Belmont Stakes so difficult to win?

There are plenty of possible explanations. A horse might be compromised by physical problems. He might encounter a superior rival. He might be a victim of bad luck or a poor ride. He might not have the stamina for the 1 1/2-mile distance, or he might not have the right style. The Belmont is won by front-runners as well as plodders, but rarely by horses who like to take command with one strong mid-race move.

Examining the failures of the last six Triple Crown aspirants may shed some light on Charismatic's prospects.

1998: Real Quiet had won both the Derby and the Preakness with powerful moves on the final turn. He accelerated the same way in the Belmont and opened a four-length lead, but weakened in the long Belmont stretch and was caught in the final stride by Victory Gallop. Many fans criticized jockey Kent Desormeaux for moving too soon, but trainer Bob Baffert defended him, saying, "That's the horse's style." Why he lost: Wrong style and (possibly) jockey error.

1997: Silver Charm led into the stretch but couldn't withstand Touch Gold's late charge. Jockey Gary Stevens heard some criticism about moving too soon, but Silver Charm's only real excuse was the ability of Touch Gold, who had been hampered by an extremely difficult trip in the Preakness and probably should have won that race, too. Why Silver Charm lost: An exceptional horse beat him.

1989: Sunday Silence had outfought Easy Goer in the first two legs of the Triple Crown. But his arch rival, who was racing on his home track and was supremely well bred for the Belmont distance, delivered the best performance of his career to run away with the race. Even though he lost by eight lengths, Sunday Silence performed well enough to have won the Belmont in many years. Why he lost: An exceptional horse beat him.

1987: Alysheba had rallied sharply to beat Bet Twice in the first two legs of the Triple Crown, but he finished fourth in the Belmont as Bet Twice won by 14 lengths. This was a time when Lasix was legal in Kentucky and Maryland but not in New York, and Alysheba had to contest the Belmont without the medication. Although Alysheba did have some trouble in the race, and 1 1/2 miles might not have been his best distance, the absence of Lasix probably accounted for his poor showing. Now that the medication is legal everywhere, Alysheba's case is irrelevant in 1999.

1981: Pleasant Colony zoomed from 15th place to first around the turn at Churchill Downs, and made a similar powerful move to win at Pimlico. But after he tried to do the same at Belmont Park, he faltered in the stretch and finished third behind Summing. Why he lost: Wrong style.

1979: Spectacular Bid was the best horse of the last 20 years, and the reason for his Belmont loss has long been debated. Trainer Bud Delp said that on the morning of the race his colt stepped on a safety pin, and blamed that mishap for the defeat. But the culprit was probably not a pin but a pinhead. Jockey Ron Franklin made a panicky, premature move to chase an 85-to-1 shot who was setting a hot pace. After surging past the leader, Spectacular Bid faltered in the stretch. Later in his career, the champion showed that he was capable of running 1 1/2 miles effectively. Why he lost: Jockey error.

There is one surprising aspect to this abbreviated history of Triple Crown failures. In an era when the American thoroughbred is demonstrably less robust than his ancestors, no horse lost a Triple Crown bid because of an injury. By contrast, physical problems stopped many horses who tried to complete a Triple Crown sweep before 1979 -- including Canonero II (1971), Majestic Prince (1969), Carry Back (1961) and Tim Tam (1958).

The lessons of the last 20 years might be summarized thus: If a horse isn't facing a challenger with exceptional ability, his main obstacle is apt to be the Belmont distance. He must not have the wrong style for 1 1/2 miles. While the Derby and Preakness are often won by a horse who seizes command with a bold move on the turn, a horse who tries to make that move at Belmont swings into the stretch with an exhausting still run ahead of him. The finish line is almost literally in the next county. Horses who win the Belmont -- whether front-runners or stretch-runners -- usually run at an even, steady pace. They need a jockey to ride patiently and mete out their energy efficiently. When Victory Gallop rallied to win last year, he ran his first half mile in 50 1/5 seconds and his final half mile in 50 1/5.

What do the lessons of the past indicate for Charismatic?

He certainly doesn't have to cope with a challenger such as Easy Goer or Touch Gold who appear poised to deliver an unbeatable effort. He is evidently coming into the race in good physical shape. And he seems reasonably well suited to the 1 1/2-mile distance; even before the Triple Crown series began, trainer Wayne Lukas was saying that the Belmont would be his best race.

Charismatic's sharp move on the turn in the Preakness was not the style that wins the Belmont. But the ex-claimer doesn't usually run that way; his Kentucky Derby victory was the kind of steady, even-paced effort that jockey Christ Antley needs to replicate Saturday.

Charismatic comes into the Belmont Stakes with an overall record inferior to most other horses who narrowly missed the Triple Crown. He is not remotely in the class of horses such as Sunday Silence and Spectacular Bid. Yet assuming that Antley delivers a patient, well-judged ride, Charismatic probably won't be stopped by any of the obstacles that foiled the last six Triple Crown bids. He faces a difficult task and a large field of challengers, but history is not necessarily against him.

Dates With History at the Belmont

Triple Crown Winners

Year

Horse

Jockey

1978

Affirmed

Steve Cauthen

1977

Seattle Slew

Jean Cruguet

1973

Secretariat

Ron Turcotte

1948

Citation

Eddie Arcaro

1946

Assault

Warren Mehrtens

1943

Count Fleet

Johnny Longden

1941

Whirlaway

Eddie Arcaro

1937

War Admiral

Charles Kurtsinger

1935

Omaha

Willie Saunders

1930

Gallant Fox

Earl Sande

1919

Sir Barton

Johnny Loftus

So Close, Yet So Far

Year

Horse

Place

Belmont winner

1998

Real Quiet

2nd

Victory Gallop

1997

Silver Charm

2nd

Touch Gold

1989

Sunday Silence

2nd

Easy Goer

1987

Alysheba

4th

Bet Twice

1981

Pleasant Colony

3rd

Summing

1979

Spectacular Bid

3rd

Coastal

1971

Canonero II

4th

Pass Catcher

1969

Majestic Prince

2nd

Arts and Letters

1968

Forward Pass

2nd

Stage Door Johnny

1966

Kauai King

4th

Amberoid

1964

Northern Dancer

3rd

Quadrangle

1961

Carry Back

7th

Sherluck

1958

Tim Tam

2nd

Cavan

1944

Pensive

2nd

Bounding Home

1936

Bold Venture

DNS

Granville

1932

Burgoo King

DNS

Faireno

The Belmont Stakes

June 5, Belmont Park, Elmont, N.Y.

Time: Coverage begins at 4:30 p.m.

TV: WJLA-7, WMAR-2

Purse: $1 million

CAPTION: Affirmed, left, is last to complete sweep of Triple Crown.