Jockey Alfredo Smith blew a race here last week by getting an 8-to-5 shot hopelessly blocked through the entire stretch run. But if losing with a superior horse was bad enough, the worst was yet to come.

After they dismount, riders at Gulfstream Park have to make a long walk through the crowd in the paddock area to get back to the jockeys' room, giving patrons ample opportunities to offer critiques of their performances. As Smith approached, a little group of irate bettors had already formed and, like a Greek chorus, reminded the rider of his sins.

"Smith, you crook! Nobody could ride that bad accidentally!"

"Hey, Alfredo! Why didn't you check (steady) the horse one more time to make it an even half-dozen?"

And those were the more charitable remarks.

Relations among horseplayers and jockeys almost always take the same form: simple abuse. When a bettor cashes a ticket he will invariably ascribe the victory to his own brilliant handicapping. When his selection loses, the fault lies with the crooked, incompetent little pinhead who rode the horse. Sometimes horseplayers' hostility toward riders actually becomes menacing. One burly New York gambler was almost barred from the track for repeatedly threatening to twist a particular jockey into a pretzel. A horseplayer at Bowie tried to leap over a fence and throttle a jockey who had just given a less-than-energetic ride.

In view of the usual nature of horseplayer-jockeys relations, I was surprised to overhear the way one bettor here addressed a rider in the Gulfstream paddock. The jockeys had mounted their horses and were leaving the walking ring when the bettor spoke to jockey Pat Day in well-modulated tones:

"Day! The rail is bad today. Every horse you've put on the inside has died. Stay outside!"

Day never acknowledged the advice. But having positioned all his earlier mounts on the disadvantageous inside part of the track, he kept this one well outside and won the race. When the horseplayer, whose friends have dubbed him the Instructor, collected a $9.40 payoff, he thought he may have deserved partial credit for the victory.

The Instructor explained how he had developed this revolutionary philosophy of dealing with jockeys. Two years ago at Hialeah, he said, he was suffering through a frustrating losing streak. Speed horses on the rail were winning practically all the races, but whenever the Instructor made a serious bet his jockey managed to put his horse in the wrong place on the track. He silently cursed the riders' ineptitude, but one day when he doped out a promising longshot the Instructor decided to take a more active role.

"The jockey on the horse was Brian Long," the Instructor recalled, "and he had shown through his riding that he didn't understand the track. I decided that I couldn't yell at him or I'd just sound like another one of the irate fanatics, so I said to him as calmly as possible: 'Every winner has been on the inside. You're 20 to 1 but if you hustle to the rail you'll win."

Long hustled, got to the rail and led all the way, enabling the Instructor to cash a $43.20 winner that got him out of the doldrums.Walking back to the jockeys' room, Long gave him a little nod as if to acknowledge that he appreciated the advice.

Of course, jockeys usually don't listen. On another speed-on-the-rail day, the Instructor told rider David Dennie correctly that he couldn't lose if he got his mount to the inside. Dennie kept his horse in the middle of the track for no good reason, and lost to a rival who had hugged the rail.

As Dennie walked back to the jocks' room, the Instructor couldn't resist a bit of second-guessing. "I told you to stay on the rail," he said. Dennie offered a lame excuse. Hearing it, the Instructor or any bettor would have been fully justified in resorting to those old standbys of abuse, invective, and character assassination, none of which can ever be totally disregarded in conversations with jockeys.