If history is a guide, Saturday's Washington, D.C. International will be won by a 3-year-old whose jockey doesn't screw up.

And history is the best guide to Laurel Race Course's great event. The factors that determine the outcome of ordinary races are largely irrelevant in the International.Its winner is usually decided by pace, tactics and -- above all -- weight.

The weights for most races in American are set according to the Jockey Club Scale of Weights that has evolved since the 19th century and decrees what horses of different ages should carry at different distances in different months of the year. For a 1 1/2-mile race in November, such as the Internation, 3-year-olds carry 122 pounds and older horses 126.

From 1953 to 1964, the International was run under those conditions. In that span of a dozen years, only two 3-year-olds won, and only five managed to finish in the money. John D. Schapiro, Laurel's president, decided that the scale was unfair to the younger horses, and so he altered the weights for his race. Three-year-olds would carry 120, older horses 127.

Those of us who think weight is an overrated handicapped factor would have doubted that Schapiro's change would have much impact. But the effect was drastic. Three-year-olds began to dominate the race. Since they started to get the seven-pound weight concession, they have won 10 of 14 runnings of the International. And in most of the years when older horses were successful, there wasn't a decent 3-year-old in the field.

Weight may not enable an inferior 3-year-old to beat his elders, but it can surely make the difference in an otherwise close race. On paper, it is practically impossible to separate the four American horses in Saturday's field -- Bowl Game, Native Courier, Golden Act and Waya -- who will be waging a race-within-a-race for this country's turf championship. But since Golden Act is the only 3-year-old among them, he figures to have an edge.

The other 3-year-olds in the International are the French invaders, Le Marmot and Son of Love II.

Trying to zero in on an International winner can be a chancy proposition because jockeys always seem to be smitten by attacks of insanity whenever they ride in this race.

Instead of riding a typical American race, with a relatively fast early pace, jockeys in the International often act as if they are in Europe, where everybody bides his time for a mile or so and then sprints to the finish. Doing this, jockeys often miscalculate and lag so far behind that they can't possibly catch the leaders, who are still fresh after setting a slow pace.

Last year the usually capable Jeffrey Fell blew the International when he kept his mount, Tiller, in last place while the front-runners were dawdling through three-quarters of a mile in 1:14 1/3. Jean Cruguet, on Mac Diarmida, made his move before Fell did, and Tiller couldn't catch him with his furious charge through the stretch.

A year earlier, Johnny D. won the International when Steve Cauthen made a perfectly timed move while Sandy Hawley was sitting on Majestic Light in last place behind a ridiculously slow pace.

In 1974, Lester Piggott gave the worst ride in the history of the International (and perhaps the world) on the great filly Dahlia; he kept t her so far behind a slow pace that even when she zoomed the last quarter-mile in an incredible 22 seconds she couldn't catch up.

Because tactics are so important in the International, a horse will have an edge if he is tractable and versatile, if he is capable of laying close to a slow early pace. In Saturday's race, plodders like Waya and Son of Love II figure to be hindered by their one-dimensional stretch-running style.

The 3-year-olds, Golden Act and Le Marmot, both have an adequate amount of early speed to go with the advantages in the weights that their age gives them. Le Marmot has the superior credentials, based on his second-place finish in the Prix de l'Arc de Triomphe, but Golden Act is steadily improving, having won his last three starts.

The two of them are the dominant horses in this International, and it may be the skills of their jockeys, Sandy Hawley and Phillippe Paquet the determine which of them will win.