In the world of serious horse bettors, there is a growing intellectual camp whose members call themselves "trip handicappers." Instead of emphasizing the traditional equine virtues, speed and class, they maintain that winners often are determined by the way races develop -- by the early pace, by the ground that horses will save or lose on the turns.

If there were a textbook on trip handicapping, the 1981 Kentucky Derby would be cited in the first chapter. The finish was almost entirely determined by the way the race developed.When Pleasant Colony and many of the horses behind him run back in the Preakness, the result may bear little relation to what happened at Churchill Downs on Saturday.

The early pace of the Derby was so fast that no horse near the lead could manage to survive. Even veteran race watchers had rarely seen anything like it: the first nine finishers in the Derby had all been running 10th or worse in the early stages of the race. The horses running 17-19-20-21 at the first turn finished 1-2-4-5. Nonentities finished a dozen or more lengths in front of such superior racehorses as Bold Ego, Proud Appeal and Cure the Blues.

Many of the stretch-runners had difficult trips. Woodchopper, the runner-up, encountered heavy traffic and trainer Jack Gaver moaned, "Just a little clearance -- that's all he needed." Partez (third) and Television Studio (fifth) lost much ground making wide moves on the turn.

But Pleasanmt Colony had a near-perfect trip, as jockey Jorge Velasquez kept him out of trouble all the way. No rider in America has a better sense of the way a race is developing around him.

Ordinary, riders are often bewildered in a big field. Kevin Wirth, the rider of longshot Mythical Ruler, gave a typical postrace comment: "Me and this other horse were going together and all of a sudden this horse comes up between us. Then this horse in the red and white colors kept knocking into me and I was just demolished."

But Velasquez can map out a ride as methodically as he might make a chess move -- even in the midst of chaos. One of his secrets of staying out of trouble with a stretch-runner is to position himself behind a strong horse who knows won't be stopping suddenly in front of him Tap Shoes suddenly in front of him. He let Tap Shoes run interference for Pleasant Colony for a while, then Flying Nachua, and finally found clear sailing as he turned into the stretch.

When Pleasant Colony scored the other significant victory of his career, in the Wood Memorial Stakes at Aqueduct two weeks ago, he had a perfect trip, too. On that day he benefited while Cure the Blues and Noble Nashua engaged in a battle for the early lead that was every bit as insane and destructive as the one in the Derby. And again, he sailed past the leadership without a staw in his path.

This is not to say that Pleasant Colony's victories in these races were a fluke. In a sense the colt helps make his own breaks. He has the ability to accelerate explosively -- he seized control of the Derby in the space of an eighth of a mile -- and his tractability will make him more likely to stay out of trouble than a ponderous stretchrunner like Woodchopper.

Pleasant Colony's victory was a respectable one by the standards of other Derby winners. Each year I analyze the times of the supporting races on the Churchill Downs card, gauge the speed of the racing strip and compare it with the condition of the track on other Derby days. This makes it possible to compare, with reasonable accuracy, the performances of various Derby winners.

If the last 10 Derby winners had run over a track as fast as the one on Saturday, these would have been their times: Secretariat 2:00 Affirmed 2:01 Spectacular Bid 2:01 2/5 Foolish Pleasure 2:01 4/5 Genunie Risk 2:01 4/5 Riva Ridge 2:01 4/5 Pleasant Colony 2:02 Seattle Slew 2:02 Bold Forbes 2.02 1/5 Cannonade 2:03 3/5

Pleasant Colony is a good racehorse. But very soon he will have to encounter conditions less than optimal. Or as handicappers would phrase it, he is going to have some bad trips, and he is going to have to prove that he can overcome them. He may face that challenge in the Preakness.