Like his Kentucky Derby candidate, Tonka Wakhan, trainer Tee Red Bernis has a name that needs a little explaining.

"A long time ago," Bernis said, "I was watching this Indian war movie with Sal Mineo on the late show. Any time anything got tight he'd hop on this horse of his, Tonka Wakhan. If I'm not mistaken, the horse wound up with General Custer.I thought it sounded neat, and I always wanted to name a horse after him."

As for the name Tee Red, Bernis' red hair and bushy red beard clearly explain part of it. The trainer said that when he started riding horses in the cajun country of Louisiana he was so small that he was known as "petit" Red -- shortened to "tee." In view of his current ample girth, this is somewhat hard to imagine, but Bernis related that his professional debut as a jockey came at the age of 6.

In the vicinity of St. Martinsville, La., where he was born, horses are everybody's obsession. "They have a big barbecue on Saturday and pretty soon everybody's drinking beer and saying, 'My horse can do such-and-such,''' Bernis said.

These disputes give rise to match races that are held on a more-or-less regular basis at tracks that don't appear on the national map: places like Cajun Downs, Carencro and Broussard's Bar and Racetrack.

"When you run against a Cajun," Bernis said, "you match the horses, set the conditions and put whatever you want on the horses. And money! They come there with suitcases. You got to put a rider on the horse and the lighter the weight the better, of course.

"Well, one day they had a $2,000 match race at Ville Platte, La., and that was the first race I rode. I was 6 years old and weighted 32 pounds. I held onto the mane and whipped and hollered for a quarter of a mile. I couldn't stop the horse after he'd won, but when he got tired he stopped and came back.'

Bernis earned $200 for his effort that day and knew, at the age of 6, what he wanted to do with his life. He won hundreds of races in the bush leagues. When he was old enough to become an apprentice at a major-league track, he was already a full-blown rider while his counterparts were just learning the business.

In his first season, 1964, Bernis was the leading apprentice rider in the nation. But by the next year, he was becoming a full-blown jockey in another sense.

He was not petit any more, and even daily three-hour sessions in the hot box could not control the expansion of his waistline. After three years as a jockey, Bernis regretfully had to retire. Six months later he had gained 70 pounds.

In his new career as a trainer, Bernis could eat as much as he wanted, but he didn't have the instant success that he had enjoyed as a jockey. He operated a modest stable, with horses of moderate ability. But in the fall of 1978 his dreams began to take shape.

Bernis saw a colt in a yearling sale by Big Spruce out of Strike A Pose, a mare he had once trained and thought to be very talented. "I ran indexes and crosses and computers," he said, "and I saw that this horse was bred to run all day long. I asked one of my owners to bid on him, and we took a shot. We brought him for $27,000."

Tonka Wakhan won a couple minor stakes as a 2-year-old at Louisiana downs, hurt himself in Florida this winter, and then went to Oaklawn Park where he rallied strongly to finish fourth in the Arkansas Derby. That gave Bernis all the excuse he needed to come to Churchill Downs for the 106th running of the Kentucky Derby.

Tonka Wakhan will justifiably be a 50-to-1 shot. In truth, the horses in the Arkansas Derby field were a dismal bunch and his fourth-place finish there didn't prove much. And Bernis has chosen to bring him into the Kentucky Derby with no races in the intervening three weeks, a schedule that almost never works here. Tonka Wakhan probably couldn't win here next Saturday even if Sal Mineo had been able to ride him.