Court tennis -- its players are few; so are its courts-

The court is nearly half again as long as a tennis court. It includes concrete side and back walls with holes through which the ball can be hit, an overhang running the length of one side, and markings on the playing surface that resemble football yardage stripes.

The wooden racquet has the feel of a club, white its misshapen head gives it the look of a tennis racquet made by a machine gone haywire.

An the wrapped ball bears a closer resemblance to a baseball than anything else.

The game is court tennis. It is not only the oldest racquet game in existence, and thus the forerunner of all other racquet games, including tennis, squash, racquets, racquetball and platform tennis; it is also quite probably the most exclusive and complex.

Court tennis traces its history back to 13th-century France. Henry VIII played the game, as did Napoleon III.

"If you know the history of this game," says Army Col. Willard K. Rice (ret.) , an avid player, "you'll know the history of Western Europe."

In June 1789, for example, Louis XVI locked the members of the French National Assembly out of the their chambers. The nearest large building happened to be a court tennis court. The assemblymen reconvented there and took what came to be known as the Tennis Court Oath, vowing to estalish a constitutional form of government.

Despite its centuries-old existence (tennis, by contrast, is barely over 100 years old), court tennis has only a comparative handful of adherents.

That stems in part from the dearth of courts. In the United States, for instance, there are just eight courts in the entire country. One is one the Whitney estate in Manhasset, Long Island. Six are at expensive private clubs, including the Boston Tennis and Racquet Club.

The eighth court -- and the only one open to the public -- is a recently refurbished one at the Tennis Hall of Fame in Newport, R.I. Rebuilt at a cost of $300,000 after being destroyed by fire before World War II and reopened last September, it is the only such facility in the county opened since the Chicago Racquet Club built a new court in 1923.

But those who do play the game -- a group that includes Gene Scott, a former US Davis Cup player and well-known tennis promoter, and James Van Alen, developer of a simplified tennis scoring system popular in some circles, make up in enthusiasm what they lack in numbers.

"It's one of the most skillfull games in the world," says Tom Greevy, court tennis pro at the Tuxedo Club in Tuxedo Park, N.Y. "I've rrely been able to see a player come in and pick up the game overnight. "If you can play and understand court tennis, you can play any bat and ball game."

"There's no other racquet game that comes close to it in terms of skill and strategy," agrees George Mars, a former tennis pro who is membership secretary of the US Court Tennis Association.

"There are so many possible ways to win a point and so many varieties of strokes it's scary. Skill is really important. Power will not necessarily help you in this game."

Part of the reason for the intriguing complexity of the game is the court. With a net dividing the opponents, and side and back walls in play, court tennis combines elements of squash and racquetball on one hand and tennis on the other.

But that's just a start.

Serving is from one side of the court only, and the serve must be hit along the court-long overhang, called the penthouse, before landing in the service box on the receiver's side.

A successful return may be hit directly into the opponent's court; scooted along the penthouse; or smacked off a sidewall and ricocheted into the other court.

The receiver may win the point outright by hitting the ball into a large opening in the rear wall on the server's side of the court. The server can win a point by hitting the ball into a smaller opening in the end wall on the receiver's side of the court, or one of four small openings under the penthouse.

A court tennis player must thus not only be able to play angles and retrieve shots like the players of other racquet games, he or she must also be able to guard specified openings, like a hockey goalie.

As complicated as this sounds, the most complex part of court tennis is a stratagem known as "the chase."

Like children pitching pennies, players try to strike the ball so it will land on a second bounce as close to the back wall as possible, in the area of the football-like yardage markers.

When that happens, the outcome of the point is in effect held in abeyance. The players change sides and attack the chase (try to better it) or defend it (keep an opponent from beating it).

The player defending the chase merely has to keep the ball in play until it appears his opponent's shot will bounce for the second time farther from the back wall than the original shot and then let it bounce.

If that happens, he wins the chase -- and the point. However, if he misjudges the shot and the ball bounces closer to the wall than to the original shot, he loses.

The one simple thing about the game is the scoring. It goes love-15-30-40 game, and six games compose a set -- just as in tennis.