Six summers ago, Doc came here for a month's diversion. He had finished medical school and passed his exams, and when the Saratoga season was over he planned to enter the profession for which he had prepared so long.

"That month," he recalled, "I really cleaned up." So he decided to postpone the start of his medical career until after the fall Belmont season. "I cleaned up at Belmont, too," he said, and the career was postponed until after the winter Aqueduct meeting.

Six years later, Doc still has not hung up his shingle. Instead, he has established himself as one of the most consistent and durable professional horse bettors in New York. And he has brought to it the same sort of discipline and diligence that he would have applied in a more respectable undertaking.

Doc's betting tactics are much different from those of the other pros in New York. They were formed by his experiences as a casual bettor in the early 1970s. He had seen a number of horseplayers wielding clipboards and charting the fluctuations of daily double and exacta prices, and he began to follow their methods. Much of the money wagered at the New York tracks came from the relatively unsophisticated clientele of the Off-Track Betting shops, and the "chartists" looked for horses who were getting relatively heavy play from the smarter bettors at the track.

"It was amazing," Doc said. "If a horse was dead on the board (i.e., if he wasn't getting on-track support) he almost never won. You didn't have to handicap; you just kept raking it in. I'd spread out my bets over all the live combinations in exactas and doubles so that I would play a lot of numbers, but it was scary how easy it used to be. There was one streak where I hit 29 daily doubles in a row."

In recent years, though, these easy pickings have disappeared. OTB players are getting more sophisticated; more important, they now have odds boards in the betting shops to help guide them. But though the game has changed, Doc has retained the philosophy that the way to beat it is to look for values on the tote board, to let his plays be guided largely by favorable odds, and by spreading his bets broadly in a race.

Clipboard in hand, he spends every racing day standing in front of a television monitor that shows exacta or daily double prices. His concentration is intense. (Once, it is said, a horseplayer near him keeled over and somebody shouted, "Is there a doctor here? This man's had a heart attack." Doc's eyes left the television monitor only for the split second needed to make a diagnosis. "It's epilepsy," he said, shoved a stick in the victim's mouth and returned to his charting.)

What he looks for, mostly, are betting mistakes by the public. "I don't have strong opinions very often," Doc said. "I'll very rarely key on one horse. I much prefer to have a negative opinion on one or two of the favorites. If I don't like a particular horse, I'll try to construct a situation where I'm sure to win if I'm right."

On Sunday he encountered a typical such situation. Rain had necessitated the transfer of a race from the grass to the main track, and one of the entrants in the seven-horse field, Vocal, never had run decently on the dirt. As Doc charted the exacta prices, he said, "Vocal has got maybe 25 percent of the money in the exacta pool; she's in the shortest-priced exacta combination. If you eliminate her and pick blindly, you've got to win." Doc played all the combinations of the four remaining contenders in such a way that he would make a moderate profit with any plausible result -- and he did.

Other horseplayers may hoot at Doc's conservative plays -- like the time he made $12,000 in show bets on a race, according to a sophisticated formula, and collected $13,060 -- but the advantage of this approach is that it immunizes him from severe losing streaks. This is a crucial consideration for any player who is in the game for the long haul -- and Doc is in it for the very long haul. He never misses a day at the track. Never.

"My philosophy started five years ago on Mother's Day," he said. "I was going to take the day off and visit my mother, but late in the morning it started pouring. In the daily double I knew there was a horse by Spanish Riddle (whose progeny love the mud) and so I went to the track and -- bang! bang! bang! -- I won $15,000. If you miss a day at the track, you're always taking a gamble that you might miss some special situation."