When a horse named Computer made his racing debut at Bowie recently, bettors could only guess at his ability and condition. The animal had only one published workout: five-eighths of a mile in a laughable 1:06.

But while the public knew nothing about Computer, somebody obviously did. So much money was bet on him that he went to the post as a heavy favorite. When he won and paid $4.80 he verified a long-established fact of racing life: information on workouts is the private property of trainers and other insiders.

It is, except in one state: California. The difference was vividly demonstrated in a maiden race here recently.

Ski Goggle, a fast 3-year-old first-time starter, would have been a good vehicle for a betting coup anywhere else in the country. But when she made her racing debut at Santa Anita, the fans knew almost as much about her as did her trainer.

The filly's past performances showed four fast workouts, most recently a five-eighths mile in 59 2/5. The times for nine previous workouts also had been made public. Moreover, a local publication called The Handicapper's Report was providing critical analyses of these workouts.

Of a recent work by Ski Goggle, The Handicapper's Report had written: "Newcomer in Doyle barn definitely run. Showed excellent speed from gate under mild coaxing while outrunning (stablemate) Sonic Speed in easy, impressive fashion. Looks just about set . . ."

With all this information, horse players at Santa Anita were in a position to bet intelligently on a field filled with first-time starters, and they bet correctly. Ski Goggle went to the post as the 3-to-2 favorite and won by 12 lengths.

Why should California horseplayers have access to valuable information that is denied their counterparts in Maryland and every other state?

In most states, horsemen have naturally resisted the introduction of rules that would ensure the accurate reporting of workouts, and nobody has pushed hard for it. Here somebody pushed: the track managements.

"Our workout rules are very, very important for handicappers and players," said Lou Eilken, Santa Anita's racing secretary. "And it's highly important to the class image of racing here. When it went into effect 15 or 20 years ago, there was some negative reaction.

"Racing has a great inertia to change. But the trainers saw that it was a big help to the public, and because purses are assigned here on a formula based on the handle, they eventually saw that the more information the public had, the more it bet."

The California system works smoothly and without inconvenience to trainers. When a horse leaves the stable area and goes onto the track, the exercise rider or trainer must identify him and tell how far the animal is going to work. The man who receives this information transmits it by walkie-talkie to official clockers stationed in the grandstand. Plenty of private clockers observe the workouts, too.

"With so many people watching," said Jeff Siegel of The Handicapper's Report, "it's almost impossible for a trainer to cheat."

Bettors here know that they can accept a horse's published workouts (or lack thereof) at face value. They usually can judge the ability of first-time starters or the condition of horses who have been away from competition for a while.

They often can judge a trainer's intentions by studying the types of workouts he has given his horse. The information adds a whole new dimension to handicapping. It is a dimension that bettors in Mayland and the rest of the United States should be permitted to experience.