Although he has raced greyhounds for more than five decades and knows how unpredictable they can be, Happy Stutz could be forgiven for thinking that his dog Unruly was a cinch to win the $130,000 Floridian Stakes.

Unruly had run 17 times over the seven-sixteenth-mile course at Hollywood Greyhound Track and had won every time. He had faced his stakes rivals in six qualifying heats and had defeated them all with ease. Unruly was so consistent that he was becoming a local celebrity, and he had been voted America's greyhound of the year in 1981.

Unfortunately, those credentials couldn't help Unruly when he broke from the No. 7 post and sped to the first turn abreast of the No. 1 dog. When his rival went wide on the turn, Unruly was clobbered and knocked immediately out of contention. In the biggest race of his career, he finished a distant sixth.

"I feel like a mother whose kid forgot his lines in a Christmas play," Stutz said. "If he were human I'd say he choked. This is the most frustrating thing that's ever happened to me in the sport." Still, Stutz knows, as well as any person alive, that the nature of the sport and the competitors makes such frustrations and surprises inevitable.

Happy Stutz was 19 years old in 1924, when signs advertising dog racing began to appear in his Hialeah neighborhood. The facilities were crude and the sport was, in fact, still illegal, but Stutz was intrigued with it, and within a year he had spent $200 for a dog named Ladonia Buck.

"I kept him as a pet," Stutz recalled. "At the time I was working as a plasterer and I'd take him to work with me. When the races started again, I turned him over to a trainer. The second time he ran I bet $20, and he got up at the wire to pay $43. I was hooked. The next day I bought two more dogs."

In those days the sport was unregulated and dog trainers would do just about anything to cash a bet. "They'd run ringers. They'd give the dogs caffeine or brandy. I tried everything but putting an outboard motor on them," Stutz said. "But there was no sure method. We all learned through trial and error that the best method was to leave them alone."

Actually, there was one dog-betting scheme that was a virtual sure-fire proposition. Some tracks, as a novelty, ran races in which monkeys rode the dogs. "The monkeys were dressed in little jockey uniforms and strapped down to the back of the dogs," Stutz said. "At the track in Cleveland I did the betting for the people who put on the races. Just before they put the dogs in the starting box, they'd pull one little monkey down and snap him to the dog's collar. So while the other monkeys would be standing up and flailing away, the one monkey would look like Shoemaker. He'd almost always win."

By the mid-1930s, greyhound racing was legalized and policed, and it had become practically impossible to execute betting coups. ("There aren't any tips in this sport anymore," Stutz said. "Only opinions.") But human nature being what it is, trainers continued to try to find some edge over their competition.

To put a dog on edge for a race, Stutz said, "We used to keep a teaser around--a big male rabbit. There was different thinking on this matter, but we'd muzzle the dog and bring him toward the rabbit. But pretty soon the rabbit got smart and would run at the dog and kick him in the face. You find that the best thing of all to prepare a dog for a race is to leave him alone and not change his routine."

Instead of worrying about how to cash a bet or win a purse, Stutz finds himself running a large-scale operation in a booming and rapidly changing industry. He has 75 dogs in training and another 125 or so on his farm, enabling him to compete at tracks from Massachusetts to Colorado. Although his dogs once competed for $100 purses, major stakes now may be worth more than $200,000. Although he once had to worry about fleeing from county sheriffs who were raiding illegal dog tracks, he now frets about the sport's public relations problems and its various intrastate political battles.

But despite all the changes that the sport has undergone in Stutz's lifetime, its basic elements still are the same. An owner's hopes, and months of planning and all handicapping logic can still be upset by one solid bump at the first turn.