Between the time he conceived the Maryland Million and the first running of the event last fall, Jim McKay was racked by a thousand doubts and worries.

Would businesses be willing to pay their money to sponsor races for Maryland-sired horses? Would breeders and trainers nominate their horses in great enough numbers to fill the nine races? Would the various factions of Maryland racing industry be able to cooperate long enough to put on the show?

To the amazement of many skeptics, the inaugural running of the Million gave affirmative answers to all these questions -- and went off without a hitch. The races drew good fields, and they drew a crowd of more than 20,000 to Laurel; the day's handle of $2.6 million was the second-largest in the track's history.

When it is run for the second time at Pimlico on Saturday, the Maryland Million will be a well-entrenched institution. The pangs of birth are over; McKay can feel the satisfaction of a proud parent as he watches his baby grow and mature.

The key factor in the Million's success -- and one that may be a lesson for the rest of the racing industry -- has been the enthusiastic support of its sponsors. Because of his own celebrity status, McKay was able to make contact with corporate biggies and enlist the sponsorship of such diverse businesses as Budweiser, the Omni International Hotel and the First National Bank of Maryland. Most of the first-year sponsors have signed on again this year, suggesting that they found race sponsorship a good investment.

"With the exception of Budweiser," McKay said, "they're not really in this to sell a product. Ryland Homes isn't going to sell any more houses because they sponsor a race. Our sponsors are in because they believe in the state of Maryland and they understand the importance of racing in its economy. The sponsors also found that this was a terrific way to entertain friends and clients. This year each sponsor will have its own hospitality tent in the Pimlico infield. It's going to look like a state fair."

By next year, McKay predicted, "We'll have them standing in line trying to sponsor races."

With the Maryland Million's financial health and future thus assured, horsemen have begun to support it much more enthusiastically. Last year, slightly more than 800 horses were nominated to the races; this year, the total was nearly 1,500. Trainers have begun to incorporate the Million into their long-range planning.

"Last year," said the Million's executive director, Richard Wilcke, "trainers needed to have us explain the procedure for nominating and entering the races. This year, they know. They're aiming for it. When you give away $1 million, you get the attention of trainers. We're going to have a lot more depth in the fields. I don't think you'll see the prohibitive favorites that we had last year."

This, indeed, was the one glaring weakness of the inaugural Million: too many races looked like mismatches on paper. In eight of the events, the favorite went to the post at even money or less. Only one winner paid more than $5.40. Few of the races at Pimlico Saturday appear to be dominated by a single standout.

The success of the Million has made the event just what McKay had optimistically envisioned -- a showcase for Maryland racing. Already the Million is spawning imitators. West Virginia has copied the idea; Ohio may do the same.

"In all the places I go for races," McKay said, "people ask me, 'How do you do it in Maryland? How do you get everybody to work together?' This state is becoming a model for the sport of racing in this country."