Before I had ever met one, I assumed that a winning horseplayer would be a man who had mastered all the fundamentals of handicapping.

That image seemed to be inescapably logical, but it proved to be completely wrong. Almost all the consistently successful bettors I have met have gaping holes in their knowledge of the game. And they don't mind a bit.

They are content to have mastered just one or two handicapping factors. In fact, this is the secret of their success. They have learned (as most horseplayers never do) that the secret of beating the races is specialization.

Obviously, all serious horseplayers have to develop some familiarity with the fundamentals of handicapping. They have to know not to bet a fainthearted sprinter going a mile and a half, or a horse coming back to the races after a two-year layoff.But such considerations are peripheral. Professional handicappers want to concentrate on the factors that are central to the outcome of races.

So many factors influence race results that a beginner could not deduce, a priori, which the crucial ones are. I spent years using horses' winning percentage as the cornerstone of my handicapping method before I realized I could never beat the races that way.

But a fledgling horseplayer does not need to waste his time using trial and error to discover the most productive handicapping factors. Instead, he should heed the methods used by bettors who achieve consistent success. If a survey were made of winning horseplayers in this country, the majority of them would fall into one of two categories: speed handicappers and trip handicappers.

I have a bias in favor of speed handicapping, because it changed my life as a horseplayer. The principal behind it is very simple: A horse's ability is best measured by the speed with which he runs. But the procedures are very complex, because horses run on different tracks, at different distances, under different weather conditions, and all these factors must be taken into account before an animal's performance can be expressed as one unequivocal number. For potential converts to speed handicapping, I would immodestly recommend the classic in the field, Picking Winners: A Horseplayer's Guide by Andrew Beyer (Houghton Mifflin, 1975, $8.95 hardback, $3.95 paper).

But even though it has worked for me, I would not necessarily recommended speed handicapping to everyone. Making speed figures requires many hours of laborious computations, and anyone who hated arithmetic in grammar school would be better off concentrating on some other handicapping method.

There is an even more persuasive argument against speed handicapping: It is becoming too fashionable. Just a few years ago, most horseplayers held the view that the final times of races were largely meaningless. As a result, speed handicappers often got incredible prices on horses they knew were overwhelmingly superior. But as more and more people have begun to use figures, the prices on winners picked by the method have shrunk in proportion. It is still possible to beat the races with speed figures, but the profitability of this type of handicapping is steadily diminishing.

The advocates of the other major handicapping method do not have this problem yet. So-called trip handicapping has not yet become fashionable because it is a relatively new approach. It was not feasible even a decade ago, before most race tracks had installed closed-circuit television monitors ofering immediate replays of races.

Trip handicappers believe that a horse can best be judged by a visual evaluation of the way he runs his races. They put their faith in their own subjective impressions, a contrast with the speed handicappers' attempt to summarize a horse's ability in an objective, unambiguous figure.

Because trip handicapping is so subjective, its "rules" cannot be neatly codified. But one thing on which trip handicappers do agree is that the crucial parts of horse races are the turns, and that races are won and lost by horses' saving ground or losing ground. They envision a track as having lanes. One horse will be racing along the rail; the horse outside him is in the "two path;" the horse outside both of them is in the "three path." The trip handicappers make careful note of the path in which a horse is running when he goes around the turn, and when the field fans out into the stretch. (In their verbal shorthand, they might describe a horse's trip as "five turn, seven entering.")

Ground lost or saved on a turn is more important than most horseplayers realize. Author Tom Ainslie calculates that for each path away from the rail, a horse runs an additional 9.4 feet around the turn. For every 11 feet he runs, he loses a length.

In addition to the paths on the turn, trip handicappers pay close attention to other aspects of a horse's race that constitute a "hard trip" or an "easy trip." A horse engaged in a two- or three-way battle for the early lead has a difficult task. A horse who sits in third place, stalking two pacesetters who are battling each other, has a much easier trip.

The trip handicappers attempt to assess a horse's cmpetitive spirit when he is battling for the lead. If he drops out of contention, they watch closely to determine whether the jockey is persevering with him or easing him up.

To a speed handicapper, the methods of the trip handicappers seem much too vague and subjective. But I cannot argue with their results; they work.

Trip handicapping does have one thing in common with speed handicapping. It demands hard work and special skills. A practitioner of the method needs to be endowed with good eyes, visual perceptiveness and great powers of concentration. A horseplayer who lacks these attributes would be wise to explore other possible ways of beating the races. And many others do exist.

Friday: watching trainers