After interminable bickering, track owners and horsemen in Maryland finally agreed this week on a plan to revive the state's moribund thoroughbred racing industry.

Chick Lang, Pimlico's general manager, hailed the agreement as "a giant step for Maryland racing." Horsemen were full of optimism. But racing fans in this area may remain cynical, and wonder if anything will ever happen to upgrade the crummy facilities at the state's tracks and to improve the crummy treatment the public gets.

Everyone has agreed for a long time that the key to a revitalization of racing is tax relief. Maryland gets 4.09 cents of every dollar bet in the state, taking about $12 million a year while track owners and horsemen are struggling financially. Even the powers in Annapolis came to recognize that this is unhealthy; Gov. Harry Hughes and legislative leaders said they would be responsive to proposals for tax relief.

But there was such enmity between horsemen and track owners that they couldn't agree on how the extra money should be split, and as a result they accomplished nothing in Annapolis last spring. On Monday, they finally did propose a unified plan: the state's share of betting would be reduced to one-half of 1 percent. Of the money the state would be giving up, the tracks would get two-thirds and the horsemen one-third.

The chances seem very good that the legislature will pass a bill that gives the industry what it wants. But this question remains: is Maryland racing really going to improve as a result?

There is no doubt that the additional money going to purses is badly needed to keep top stables from leaving the state. At present, a $14,000 claiming race in the state will offer a purse of $8,000. The same class of horses runs for $9,500 at Keystone or the Meadowlands and for $11,500 at Belmont Park. That's enough of a difference for the trainer of a good stable to consider sending his horses elsewhere, and the gap has to be closed.

It was only six years ago, however, that Annapolis passed legislation that boosted purses in Maryland to keep them competitive with other states, and after such a short time the horsemen are in trouble again.

The reason, of course, is that this purse money comes from a percentage of the money the public bets, and fewer people attend Maryland tracks every year. It doesn't help much to get a bigger percentage of the pie if the size of the pie keeps shrinking.

If track owners take money ceded by the state and use it to improve their facilities and offer a better product, Maryland thoroughbred racing might be revived

This is what happened in the state's harness industry; Frank DeFrancis led the fight for a tax-relief bill, used that money to refurbish Freestate Raceway, turned it into a delightful physical plant and now has a booming operation.

Maybe the managements of the thoroughbred tracks will do the same. Maybe. But these are the same track owners who have enjoyed profitable periods in the past, who have been given increases in the take from betting before, but who have let their physical facilities and the overall quality of their product deteriorate.

Not only do they lack DeFrancis's kind of vision, they don't even bother to keep their plants clean.

If the plan recommended by horsemen and management does become law, the tracks will get about $6 million a year from the state. With that much money, the track owners could, in a few years, change the face of Maryland racing.

Or they could fatten their profits over the short term while permitting the sport's health to continue its decline.

Maryland racing fans who understand the importance of past performances know which possibility they would bet on.