Whenever a 3-year-old comes from far behind and finishes fast in an early-season stakes race, his owner, trainer and jockey will start to think he is the type of runner who will be well suited for the Belmont Stakes.

There is nothing wrong with this general mode of thinking. Much more than the other Triple Crown races, much more than most major stakes in America, the Belmont is won by a certain type of runner. But most people in the racing world totally misunderstand what that type is.

Year after year, strong stretch-runners come into this classic with much fanfare, because everyone assumes they will be more effective at 1 1/2 miles. Year after year, these horses run poorly in the Belmont, yet the myth endures. But anyone who takes a cursory glance at the Belmont's recent history will see that this is anything but a stretch-runners' race.

In the last 14 years, only three confirmed come-from-far-behind horses have won here: Little Current, Temperence Hill and Caveat. During the same period, six horses have led all the way to win. Front-runners win the Belmont more often than the Preakness, which is universally thought to be a highly speed-favoring race.

The "Belmont type" definitely is not a horse with a stretch-running style. Nor, of course, is it a one-dimensional speed horse. The proper style for the Belmont falls in the middle of those extremes, and without the right style a horse has little chance in this race.

Understanding the nature of that style helps to explain many Belmont Stakes upsets of the past, and it should shed light on Saturday's race.

The special nature of the Belmont becomes clearer when we compare the way it is run with the way the Kentucky Derby typically is run. In most years, the Derby is decided when a horse takes command with one decisive move. This year, for example, Spend a Buck accelerated away from the field by running the second quarter-mile in 22 4/5 seconds. After opening a six-length lead, he never was threatened.

Most often, however, the winning move at Churchill Downs is made on the final turn. Gato del Sol, Pleasant Colony, Spectacular Bid, Genuine Risk and Canonero II made similar powerhouse moves that carried them to victory. To win the Derby, a horse usually will run at least one quarter-mile in 23 seconds or less, and that acceleration will enable him to break loose from the pack.

But the character of a 1 1/2-mile race is much different from that of a 1 1/4-mile race. The Belmont distance is too long for a horse to seize control with a single burst of speed. Horses with the talent to throw a :23 quarter at their rivals in midrace cannot employ that style to win the Belmont. Spectacular Bid and Pleasant Colony had used their explosive acceleration to win the first two legs of the Triple Crown, but when they made their usual moves in the Belmont they came up short.

At 1 1/2 miles, nobody has to run explosive quarter-miles to win. Nobody has to make powerful stretch runs. The distance favors horses with at least a modicum of speed who can sustain a fairly even pace the whole way. When the undistinguished colt Summing upset Pleasant Colony in 1981, he ran his six quarter-miles in :24 1/5, :24 3/5, :25 1/5, :25 1/5, :24 3/5 and :25.

The style hardly was brilliant, just effective.

If a horse is a front-runner with speed that can be meted out at an even pace, he is the most effective type of Belmont runner. Affirmed had that kind of tractability. So did Swale, who led all the way last year by running quarters of :24 4/5, :24 3/5, :24 1/5, :24, :24 3/5 and :25.

Yet, the quintessential Belmont style might belong to the colt who is going to win the race's 117th running Saturday. Details tomorrow.