Jack Davis' colleagues from Harvard Business School's Class of '49 grew up to head such major corporations as Bloomingdale's, Johnson & Johnson, Capital Cities Communications, Zayre, General Tire & Rubber and E. F. Hutton. Fortune magazine, tracking the success of that postwar class, called the graduates "the class the dollars fell on."

Today Davis, 54, knows all about falling dollars. As the president of Resorts Internatonal, he was the man who several winters ago left his Bahamian home to take up residence in bleak, cold Atlantic City. His plan was to open the first casino on the East Coast. Now, exactly a year after the first bet was placed in that casino, Davis runs a money-making machine that earns more than three times the largest Vegas casino, a monopoly at which his schoolday chums must marvel. Davis only allows as how they once considered his job "more lightly than they take it now."

In the early days Las Vegas watched him with scorn. Other investors hedged their bets, waiting to see if Davis' company would collapse under the weight of an ocean-front white elephant. But to this preppy-looking executive, the pundits who rave about the ray-off of his company's "big gamble" in Atlantic City have it wrong; to his thinking, the gesture was never a crapshoot "if you believe people have a basic urge to gamble."

The physical proof:

When the casino opened last Memorial Day weekend, the gaming floor covered 33,000 square feet. The space has since doubled.

Eighty gaming tables have been joined by 49 more.

Where there were once 850 slot machines, there are now 1,750.

For his prescience and stewardship, Davis earns a salary of $125,000 annually, plus perks. He doesn't gamble, except for occasional forays to Vegas to observe the state of the art. Most people, his press aide admits, expect Davis to be a swarthy, beefy, tough-talking man with a goon's personality. In fact, he's a button-down, bottom-line exec who jogs on the Boardwalk in the morning.

This summer the competition begins. An East Coast branch of Caesar's Palace is poised to open any day and Bally's operation should follow later in the year. What if his casino-that last year accounted for $86 million of his company's $98 million in earnings-had flopped?

Says Davis: "I'd be on some lonely beach." CAPTION: Illustration, No caption, By David Seavey