During most of the year, local horseplayers can fall into a monotonous routine, following the Maryland racing circuit from Laurel to Bowie to Pimlico.

But from late July through early September, Maryland's major tracks are closed and no thoroughbred tracks are operating within a 50-mile radius of Washington. Bettors must venture to Timonium, Charles Town or Delaware Park.

These are all very distinctive places, and their singularity suggests one of the reasons that playing the horses is such a challenging game. There are no universal rules of handicapping; principles that seem axiomatic at one track may be worthless at another.

A horseplayer who hopes to survive at a new track had better learn its special characteristics quickly. For the benefit of handicappers who aren't fully familiar with all of the tracks in this part of the country, I offer a few suggestions.

TIMONIUM offers a seven-week season that shouldn't even exist. During the rest of the year, Maryland racing has major-league pretensions, but Timonium offers third-rate racing in a fifth-rate facility, with an antediluvian grandstand and grossly inadequate parking.

The track has only one saving grace: like most "bull rings," it is a relatively easy place to handicap.

Five-eights of a mile in circumference, Timonium has the characteristic of most small tracks: the sharp turns and short straightaways deter horses who try to come from behind. Betting an animal who doesn't figure to be running first, second or third in the early stages of a race is always a risky proposition. Horses with speed and inside post positions have a formidable advantage.

Maryland regulars who go to Timonium will confront one type of race they never see at the major tracks: four-furlong sprints. Such events obviously demand a lot of speed and horses who show moderate sprint speed at the major tracks usually aren't quick enough to win these dashes. Horses who have displayed quickness in 4 1/2-furlong dashes at Charles Town or five-furlong races at Penn National traditionally fare well in the short races at Timonium -- even though they might seem slightly out-classed.

King Leatherbury splits his stable between Timonium and Delaware Park during the summer but still always manages to dominate the trainer standings at Timonium. A lesser-known trainer to watch is Charles A. Harding, who has done very well at Timonium during the last two years.

CHARLES TOWN, like Timonium, is a bull ring with a bias that favors horses with early speed and inside posts. Unlike Timonium, it offers its customers pleasant and comfortable facilities. But Maryland regulars who venture to West Virginia usually get into trouble because their usual handicapping methods do not work there.

In particular, handicappers cannot evaluate the relative class of horses simply by looking at the claiming prices for which they have recently run. A $3,000 claiming horse at Charles Town will usually be inferior to an invader from Maryland or Penn National who has been racing for the same price tag.

Visitors to West Virginia should learn (before they go broke fast) that there is also plenty of differnece among the many horses who race in the $1,600 claiming category. Most events in this rock-bottom class have conditions of eligibility, and a field of "horses which have not won a race since October 15" will be a lot different from a race for "nonwinners of three races since October 15." The Charles Town cognoscenti pay careful attention to these distinctions.

DELAWARE PARK has an enthusiastic local following, for obvious reasons; It is probably the loveliest race track between Saratoga and Hialeah.

But Delaware's racing programs are frequently unattractive. Small fields make many races undesirable betting propositions. And this year the track has confronted its patrons with a whole new liability.

When Maryland sharply curtailed the use of the drugs Butazolidin and Lasix this summer, Delaware kept its drug rules relatively liberal, catering to the desires of the horsemen it so desperately needs to fill its races. And the track won't even publish a list of who is getting what.

Since the majority of horses at Delaware come from Maryland, handicapers must guess what (if any) impact the different drug rules will have on form. Occasionally the effect seems very dramatic. The filly Veiled Look won by 12 lengths at Pimlico when drugs were legal, ran dismally as a 1-to-5 favorite at Bowie after drugs were banned, then came to Delaware and ran like a tigress.

This is the sort of guessing game I have no desire to play. And, unfortunately, there are no powerful angles that will simplify handicapping at Delaware. The racing strip, resurfaced before this season, seems uniform; it gives no particular advantage to horses with certain running styles or post positions.

The dominant trainers at Delaware will surely be the usual Maryland biggies -- Leatherbury, Buddy Delp, Dick Dutrow and Ron Alfano.

Perhaps the most notable early season trend at Delaware has been the strong performance by the horses who have shipped in from Churchill Downs. Betting the Kentucky invaders blindly would have produced a solid profit during the early part of the meeting -- but it's probably too late to capitalize on that angle now.

A bettor seeking esthetics as well as profitability may do well to pass by Delaware and continue north to Monmouth Park. The Oceanport, N.J., track has an attractive plant and competitive racing and -- best of all -- it offers a shortcut to success at the betting windows.

Since early July, the inside part of the racing strip at Monmouth has been like a bog. Horses in inside post positions can generally be eliminated. bHorses who race half-decently along the rail can be tabbed for a bet in their next starts. And most of the Monmouth crowd isn't sophisticated enough to realize what is going on. Regulars at the New Jersey track report that the pickings are easy.

Of course, any horseplayer with the chance to do so should be willing to forsake the easy money at Monmouth and the relative convenience of Timonium and Charles Town in order to gamble at the queen of American race tracks: Saratoga.

No track offers classier racing; none offers such a consummate challenge to a handicapper's skill. Thus, for the next four weeks, this column will emanate from upstate New York.