BALTIMORE - The racetrack is a flattened circle that goes around and around, carrying with it horses and history and days and years that chase each other's tails and tales.

The sun will rise tomorrow morning above the oval at Pimlico Race Course, a dowdy plant gone shabby in its dotage, and not long before it sets the 132d running of the Preakness Stakes will be held, giving Pimlico its annual spotlit moment in an otherwise shadowed existence.

Exactly one year ago, as you will be reminded quite frequently, the Preakness witnessed a dreadful collision of greatness and gruesome luck when Barbaro, the Kentucky Derby champion, shattered his right hind leg with a misstep in the opening furlongs of the race.

Two minutes later, Barbaro had been expected to sweep across the finish line following a romp around the length of the track, ending the route with his usual burst that humbled the rest of the field.

Instead, he made it only to that point on the first pass, pulled up by jockey Edgar Prado, who quickly dismounted and leaned his weight against the terrified colt to steady him. It was the finish line for Barbaro, although the denouement took eight months to arrive, following heroic medical efforts that evening and the next day and a fingers-crossed recovery period that eventually lost its long-shot battle against overwhelming odds.

There was nothing in the moments leading up to the Preakness that could have foretold what would take place. Along with the Jackson family and trainer Michael Matz and some other reporters, I did the walk-over from the Stakes Barn behind Barbaro, along the wood chip trail that leads to the track, across the racing surface, and onto the turf course where the horses were saddled and readied in front of the massive crowd.

The sheer size of Barbaro is what you remember. Walking behind him, you could see that fans lining the fence would pause for a moment in their cheering as they took in the animal. It was like suddenly watching a tank pass by, his immense hindquarters rolling with each step like a powerful engine idling throatily.

In the saddling area, it was giddy. Barbaro reached down and munched some of the turf course and someone joked with Matz that maybe this was a grass horse, after all, a reference to the speculation that Barbaro's accomplishments on dirt might pale next to the domination the high-stepper would have shown on grass.

Prado mounted, and Barbaro, full of himself, playfully bucked him a couple of times, and everyone laughed about that, too. This horse was going to win the race, and then he would win the Belmont, and then, whatever, the Prix de l'Arc de Triomphe, the Breeders' Cup, the Indy 500. Whatever.

All in a moment on a perfect spring evening.

Today at Pimlico, one long year later, it is possible that Roy and Gretchen Jackson and Matz will finally be united in the winner's circle, a meeting more poignant than ironic given the fragile nature of the sport.

The Jacksons will present a trophy to the winner of the Barbaro Stakes, the renamed Sir Barton Stakes, which will be run as part of the Preakness undercard. Matz has a horse, Chelokee, entered in that race, after deciding that the Preakness would not be the best spot for the still-developing 3-year-old. That is typical Matz. Another trainer might have gone for the tougher race, the bigger stage - Chelokee could probably have competed well enough there - but it wasn't in the best interest of the horse, so Matz passed.

When the Sir Barton was renamed late last year, Maryland Jockey Club officials hoped that Barbaro would be well enough to take a ceremonial walk on the track in front of the crowd today. Instead, only his memory will cross the surface as a reminder of how quickly everything can change.

Barbaro probably would have enjoyed the attention - he knew exactly who he was - but he would also have wanted to run. That would have been sad in itself, although nothing compared to the reality.

When the Preakness is finally held today, nine colts will chase each other, and the race from a year ago will be pushed back one line in the record book. Street Sense, this year's Kentucky Derby winner, has a good chance to win and be pointed toward a Triple Crown at the Belmont Stakes in three weeks. If the trifecta also included Hard Spun and Curlin in some order, as it did at Churchill Downs, few would be surprised.

Watch them closely, because these horses will disappear soon, although hopefully not as suddenly or tragically as Barbaro. But this is a disposable business that asks too much of its athletes.

If horse racing could ever achieve some continuity - can you imagine the interest in a Breeders' Cup Classic containing, say, Smarty Jones, Afleet Alex, Invasor, Bernardini, Ghostzapper, Barbaro and Street Sense? - perhaps the game could survive as something more than just a beard for slot-machine parlors.

Racing, however, and this is an irony for a business built on pari-mutuel wagering, is not that lucky. It has been overtaken by easier, less-mind-taxing methods of betting, and by the great crashing tide of other sports in this country. Racing's greatest heroes, bred for speed and not endurance, either don't last physically or are hustled off to the breeding shed at the first opportunity.

If Street Sense did win the Triple Crown, he'd be immediately packed in bubble wrap and shipped to Kentucky to await the offers. There are no living Triple Crown winners - Seattle Slew passed away in 2002 at the age of 28 - which would make Street Sense's earnings potential as a stallion too high to risk on the racetrack.

And so the game goes around and around, like the track itself, carrying the colors and thrill of the moment, but also the memory of the moments that never were.

No walk-over tomorrow, thanks. It only gets your good shoes dirty and breaks your heart.