Rosecroft Raceway built a new paddock in 1974, a new clubhouse in 1975, then followed with new lighting, a new racing surface and a new aluminum hubrail last season. That's nearly $5 million spent for major improvements in three years.

Not bad. There are thoroughbred tracks in the area that won't spend that much on themselves in the next 50 years or until their old stands start to literally fall apart.

Rosecroft gambled some money in order to try to make money. Washington fans have responded appreciatively. The only thing old about Rosecroft these evenings are the dramatic drops with the last blink on the odds board, the figures occasionally cascading from 4 to 5 to 1 to 5 as the field hits the first turn.

"We're starting to get to the point where we can compete with the big tracks," Earle Palmer Brown, the president of Rosecroft and the Harness Tracks of America, said recently. "The type of person who comes here is not the same as the one who goes to Bowie, for example. We have a different class of people, and they are not necessarily serious horse players. They will have dinner, watch the races, enjoy an evening out with the family."

Rosecroft also works at attracting black and young people, singly and in groups. This, too, is in sharp contrast to Maryland's thoroughbred plants which apparently fail to recognize that the black bettor has been their one big plus factor during the last decade despite an overall decline in average attendance.

"We've been advertising for a number of years to the black community," said Brown, who runs an advertising firm in Bethesda. "The black income in Washington is higher than any other place in the country. Many blacks hold responsible jobs in government agencies. We want these people. Anyone who doesn't is short-sighted."

Part of the reason for Rosecroft's recent success traces to the cooperation it has received from state government. More dates and more tax revenue from the wagering have been granted, rather readily, by the same gentlemen in the General Assembly who tend to automatically oppose virtually everything the thoroughbred tracks request.

"The standardbred industry here has as much right to survive as anyone else," Brown said. "For 25 years we have been stepchildren, in terms of Maryland racing. But now they are listening to us in Annapolis. We finally got our own commission. We have been able to get our legislation through, by and large, because we don't fight in public.

"Or maybe it's partly because the harness people historically, in this country, have always been fighting for their life. They have been willing to get their hands dirty. Why should racing be afraid to ask the state for help, for example, if it is justified. This is a $22 million-a-year revenue source in which the state invests $150,000. Yet the state still is not willing to actually give up any of the money it gets from the sport.

"We are generating more income partly by the takeout having been increased on the triples and the exactas. These pools account for approximately two-thirds of our total handle. They are not the best bargains we offer for the bettor, but the public wants them, the possibility of a big return for a small investment.

These are the good nights for Maryland's harness racing, before troubled Laurel Raceway opens later in the month. But Brown is acutely aware of Rosecroft's present problems and others which lie ahead.

"Getting rid of the 20 percent withholding on winnings over $1,000 is the No. 1 priority. It has pushed our industry farther back in the corner," he said. "It really hurts the churn, the amount of money available to be bet on later races. Energy costs are spiraling, and the HTA tracks should become more uniform in several matters, in the way program information is presented, for instance, and the way colors are used to key the races on the program."

And Virginia?

"I think their first tracks will be built in the Tidewater, which has been a good harness breeding area," Brown declared. "It will be interesting to see how any Virginia track can survive without exotic betting, and who is going to put up the money to build the tracks under the stringent stipulations imposed by law? But Virginia coming into racing will make it only more vital that Maryland have a top-flight operation near Washington."

Racing is changing. Rapidly. The days of the Moris and the Lindheimers are long gone. Good management is more important than every if a race track is to prosper.

Many harness tracks are fortunate in that respect. Whereas thoroughbred tracks often seek safety in promoting accountants to top executive jobs, the trotting tracks lean to men of promotional savvy more attuned to the times. And Brown currently is their national leader.