"When we got to the three-quarter mark," said Jack Kopas, "I knew that unless somebody just fell dead something good was gonna happen." Kopas is a fellow for understatement, because that something good was a world record.

Still, Kopas and the horse that set the record, Jade Prince, probably will not cause undue fuss this weekend because their competition, though major, hardly is the Preakness.

But the William E. Miller Memorial Pace at Rosecroft tonight does have $40,000 to be split into two races - and enough fine 3-year-olds so that Jade Prince just might not be the class of his division, let alone the entire 15-horse show. Or even the best in his own born for that matter.

At 48, Kopas has been seriously into harness racing for nearly 33 years, coping for the most part in his native Canada by turning mediocre colts into better-than-average trotters and pacers. Now, all of a sudden, Kopas has an abundance of talent to develop.

"We'll break around 20 yearlings a year," he said, "and to come up with four that go better than two minutes is not likely to happen again. I'm kinda small time, so it's even more unlikely that I'd get a pair like that."

The second part of that pair is Nat Lobell, which will compete in the other division of the Miller tonight and seemed far the more promising horse on arrival at the Kopas complex near London, Ontario. Each horse came for $19,000.

"I had nothing to do with buying Jade Prince," said Kopas, "although I imagine he was the cheapest of the Meadow Skipper crop that year. He was hurt when I got him and a slow learner."

"Nat Lobell I had a hand in, because we were looking for a special (Nansemond) bloodline. We picked two, but the other one I don't even want to talk about. He wasn't much." In truth, Nat Lobell was fine early last year, then developed pneumonia.

"You never know what you've got till you go racing," Kopas added, "especially with colts because the percentage of 2 year olds that even get to the races is small. You're asking a baby to do a man's job."

On Oct. 5, though, after overcoming early knee troubles and failing to grasp his lessons quickly once he was physically mended, Jade Prince pulled off the sort of performance men such as Kopas dream about but rarely experience.

It was at the International Stallion Stakes at Lexington, Ky., and Jade Prince bettered his previous best by three seconds in winning his first heat in 1:55.1. An hour later came the record.

"Everything had to be perfect - and it was," said Kopas. "The track was perfect, the weather was perfect, we caught the race perfect. We just had a perfect trip. I couldn't believe it when I saw that three-quarters time of 1:24.3."

Another horse in Jade Prince's heat tonight, Fulla Strike, also was timed in 1:54.1 last year. That was a time trial, though. But Fulla Strike is coming off a 1:57 victory in his last race, at that swift track in Lexington, while Jade Prince's last outing was 2:00.4 success in Canda.

Although perhaps less versatile, Nat Lobell may be the stronger Kopas horse. He seems to be keeping headier company of late in New York and may well be the winner of his division tonight.

"Seven of the 15 horses will be coming off wins," said Rosecroft racing secretary Billy Perkins. "This will be the first meeting of the horses that'll be competing over the Grand Circuit, although we're not part of it."

Although the trip from Canada to Rosecroft and a night of serious racing and then back home early the next day is exhausting, it is not quite as tiring as if Kopas were at home.

"There I'll get up at 6 a.m. to start training the horses an hour later. When I'm racing in the area, I won't get off the track until after 11 p.m. When I'm on the road, at least I'll get some rest on the trip home."