Fans at this week's Washington Star International tennis tournament can pick up tips on strategy and strokes and cut down on their errors on the court by scrutinizing the games of the top players.

The matches at 16th and Kennedy Streets NW are played on Har-tru, a soft surface conducive to baseline rallies and to the determined scrambler.

On such courts, players who rely on finesse, court tactis and a full repertoire of shots can cut the serve-and-volleyers down to size.

Although many pros have unorthdox motions and can compensate for their less-than-classic strokes by using strength or athletic ability, most great players are masters of the game's fundamentals. And the fundamentals are what the spectators should concentrate on.

Tennis instructors constantly tell their students to keep their eyes on the ball and to get their rackets back as soon as possible on their forehands, backhands, and volleys. Pros get their rackets moving well before their opponents' shots cross the net, and they watch the ball, especially at net, until the point of contact.

The competitors in the Star tournament are well-conditioned athletes who stay on their toes throughout the match, ready to mive in any direction and to pounce on a weak return from their opponents. They also return to the center of the court after they have hit the ball, rather than stopping wherever they have made contact.

Norman Fritz, the top senior tennis player in the Middle Atlantic States and one of the tournament's umpires, says that "After a week of sitting in the chair, my games picks up amazingly, I automatically absorb the players' techniques - hitting with topspin, getting the racket back early, keeping the ball deep in the court.

"Even top tennis players maintain basic techniques which lead to good tennis habits. They get all their weight into the stroke to get power, instead of hitting with their arms."

Jimmy Connors throws himself into each ball, with the force of a missle leaving its launching pad. He advises the average hacker to look at the professional's preparation and footwork. Watching the ball is essential. If you don't keep your eyes on the ball, you can't hit it."

He points out that pros, because of their speed and anticipation, are rarely caught off balance or out of position. Connors keeps the ball as deep in the court as he can, but every row and then he hits a shot into the forecourt to throw into his opponent off.

Known for ferociously smaking back all his shots, Connors says, "I don't hit the ball hard. I just hit it at the right time." What he means is that he attacks the ball at the top of its bounce.

Gary Plock, 22, No. 1 on the tennis team at the University of Texas for the last four years and a Junior Davis Cupper two years ago, realizes that "Connors has a lot better concentration than I do." Experienced players are not distracted by crowd noise, photographers or weather conditions. They keep their minds on their games.

Plock, who lost in the last round of the qualifying matches for the tournament, explains, "I know what's bad in my game and I watch players who don't have that weakness. Some of the most common mistakes of country, club players (not bending their knees enough, rushing shots or tossing the ball erratically on their serves) the pros make also."