The horses who populate the rock-bottom $5,000 claiming races in Maryland are by definition low-class animals. Yet nobody who has ever worked with the gelding Time To Bid or followed his fortunes will ever think he is anything but the embodiment of thoroughbred class.

In many ways, the 13-year-old is the most remarkable horse competing at Laurel this winter. He won races every year since 1977. He has made 178 starts in his career and finished in the money in two-thirds of them. His next victory will be his 50th, one of the rarest milestones in the sport.

Time To Bid commands so much affection and respect among horsemen that he has been claimed for $5,000 twice in his last five starts. Glenn Lane, one of the most successful owners in the country, took him because he thought that shooting for the horse's 50th victory would energize his whole stable. But Arnold Zimmerman, who had trained him through much of 1987, claimed him back after he won No. 49. "It was a strictly nostalgic move," he admitted.

Most horses who win so many races start their careers in high-class company and keep winning as they keep dropping down the ladder. (The last 50-race winner to compete in Maryland, Port Conway Lane, fit this description.) But Time To Bid has been a cheapie all his life.

Humbly bred, he launched his career in a maiden-claiming race at Rockingham Park in New Hampshire on July 27, 1977. Trainer Butch Lenzini still has dim memories of him: "He was a big, strong, good-looking chestnut, but he had problems. He might have had a few ankle troubles."

(A decade later, Zimmerman describes Time To Bid as "a big, strong good-looking horse . . . with trouble in both his front ankles.")

Time To Bid won his second start, but Lenzini and owner-breeder Art Pomponio lost him when he was claimed for $10,000. Thus began a 10-year odyssey around the lower echelons of the racing game.

Time To Bid has changed ownership 15 times, by claims and private sale. Although he won a few allowance races at minor tracks, he has basically been a claimer all his life; the highest level at which he ever won was $22,000.

He spent most of his first three seasons at Keystone Race Track (now Philadelphia Park), and the years 1980-85 around Thistledown, in Ohio. He came back east in 1986 and was based primarily at Penn National in Harrisburg, with frequent forays into Maryland.

But the animal was unfazed by any of the changes. He never had a bad year, and never was sidelined by injury long enough to have an unproductive year. As an 11-year-old in 1986 he made 22 starts, winning six and finishing in the money 18 times.

The whole key to this durability and consistency, Zimmerman said, is Time To Bid's conformation.

"He's almost perfect," the trainer said. "He's got good feet, good bones, a short cannon bone, a properly angled pastern. He can be a little bit sore {because of his ankles}, but it's not the type of thing that eats at your conscience to keep him in training."

Time To Bid has been soundly beaten in his last two starts at Laurel; the competition here may be getting a little too tough for him. (He'd probably like a distance a little shorter than six furlongs, too.)

But Zimmerman would like him to win No. 50 at a major track like Laurel, if possible, and he believes that the horse still can do it.

"It's hard to bring him up to a race and know that he's feeling good," the trainer said. "Everything is ho-hum to him now. He's not real thrilled about training and in the paddock he looks like he's going to fall asleep from boredom. But he still has days where he feels good."

On one of those days, Time To Bid ought to be able to do once again what he has done 49 times in the past.