A generation ago, horse players rarely talked about track biases. Neither the phrase nor the concept was mentioned in the handicapping texts of the time.

But bettors are becoming increasingly sophisticated, and when Laurel unveiled its new racing strip last week the smart ones were watching closely to determine its tendencies. Almost every successful contemporary handicapper knows that he can get one of the strongest edges in the game when a track favors speed horses or stretch runners, inside or outside post positions.

Last week Laurel, observant bettors found such an edge, and there will be numerous opportunities to profit from it in the days ahead.

Detecting a track bias requires no arcane skills. A handicapper should concentrate his attention on certain parts of races and watch to see whether horses on the inside or outside are performing consistently better.

A few strides out of the gate, are inside or outside horses usually in front? On the final turn, do horses rallying in the middle of the track sustain their moves or flounder? In the stretch, do horses on the rail tend to collapse, or do they consistently resist horses outside of them?

A bettor also should review the results of each day's races, noting the winning post positions and the frequency with which horses led from wire to wire.

These observations produced a clear-cut conclusion last week: the rail at Laurel was disadvantageous on most days. On Wednesday, in particular, the horses seemed to be strung out on a diagonal line a few strides out of the gate; outside horses were breaking fast and those on the inside were breaking slowly. On Saturday, almost every winner raced about four or five horsewidths from the rail in the stretch.

During the first four days of the meeting, front-running horses captured only two races. In the entire week, only one horse succeded from post position No. 1. That was unbeaten Cure The Blues, whose jockey hustled him out of the gate and steered him off the rail as quickly as possible.

Such conditions do not exist (as some horse players suppose), for any nefarious or conspiratorial reasons. There are more than 400,000 square feet of dirt on a racing strip of Laurel's size, and keeping all that dirt perfectly uniform is a very difficult task. "Because of the slope of the track," General Manager John Mooney said, "the soil tends to slough to the rail."

When such conditions exist, the bettor needs flexibility more than he needs genius. He has to be willing to subordinate his handicapping judgments to the track bias. If he falls in love with a speed horse breaking from post No. 1 he has to be willing to disregard his natural perference and bet according to the dictates of the bias.

Horse players who came to Laurel Monday preparing to do this got a rude awakening. The track was uniform; the rail was normal. Front-runners captured four of the nine races; horses were not making the big swoop-around-the-field move on the turn that they were two weeks earlier. The game had changes. Mooney explained, "Water trucks don't provide enough moisture for a race track. Saturday's rain was the first decent rain we've had. That finally helped us to consolidate the track."

Even with the track uniform now, last week's bias will provide continuing money-making opportunities.

The most productive use of track biases in handicapping comes by following horses who have been hindered by the racing surface in their previous starts. On days when the rail is bad, horse players should make note of every animal who races on the inside -- preferably ones who have shown some sign of life there -- and be prepared to bet them in their next start. On opening day, for example, a horse named I'm Destructive broke from the inside post and battled for the lead along the rail, but faded to lose by 10 lengths. On Tuesday he came back against similar company and paid $23.40.

Also on opening day Ashford Mine went to the lead, dropping to the rail and tired in the stretch. On a normal track he should stand out in today's sixth race. Last Thursday, the only horse who was able to win along the rail was Twivil. He steps up in class and runs in today's seventh race. There will be many such plays over the next week or two, and students of track biases know that in the long run they figure to be very profitable.