Hockey fans who rejoice in excellence of play and a home-team victory will probably have to be satisfied with excellence tonight, when the New York Islanders play the Washington Capitals at Capital Centre.

The Islanders not only possess a bonafide contender for the Stanley Cup. They also feature, in Mike Bossy, Bryan Trottier and Denis Potvin, three of the game's true superstars.

Bossy in his second season has been scoring goals at a faster rate than anyone in the history of the sport, averaging more than three every four games. Entering last night's game with Buffalo, he had 61 this season, following a rookie record 53 a year ago.

Trottier leads the NHL with 122 points, on 45 goals and 77 assists, and is certain to repeat as the NHL's allstar center. Besides his point production, he is a fine checker, an outstanding two-way player.

Potvin's 94 points are high among NHL defensemen and he, too, is an outstanding two-way man. He won the Norris Trophy a year ago as the NHL's best defenseman and it is unlikely he will be challenged in this year's balloting.

When Bossy was a junior at Laval, Washington scout Billy Taylor called him "the best player in Canada from the blue line in." In two years, he has become the best player in hockey from the blue line in.

And, despite his apparent fragility at 6-feet and 185 pounds, he has learned to play at both ends of the ice.

"He has the fastest hands I've ever seen," said the Islanders' coach, Al Arbour. "When he gets free in the slot, he picks the puck up so fast and gets it away so accurately that many times the goaltender doesn't have a chance. He is a natural-born goal scorer."

"I almost never look where I'm shooting," Bossy said in attempt to explain his success.

"I try to get the puck away as fast as possible. That gives me the advantage on the goalie. Sometimes the puck doesn't go where I want it to, but it goes in anyway."

The Capitals chose Greg Joly and Mike Marson in the 1974 amateur draft while Trottier then only 18, was still available. Then, after the Islanders chose him, they told him to play another year of junior hockey.

Like Potvin before him and Bossy after him, Trottier earned the Calder Trophy as rookie of the year. In four NHL seasons, he has scored 412 points. If he captures the scoring title this season, as seems likely, he will be the first expansion player to do so.

"He has more pure power than anyone can imagine," admiring linemate Bossy says of Trottier. "He's 200 pounds and he knows how to use it. He skates crouched down, which makes him look smaller than he is. Guys who try to body him usually wind up bouncing off themselves."

"My father taught me the value of defensive hockey and hard work," Trottier said. "The goals will come if you keep on working. My only goal is to work hard and help the team. The rest will come."

Although it seems that Potvin has been around a long time, he is only 25 and has played just one more season than the Capitals. His principal goal is to play on a Stanley Cup winer and he thinks this could be the year.

"I see a Cup victory for this team as a real possibility," Potvin said. "I feel this way because of our personnel, the way we are together on and off the ice-and the fact we are getting the big goals every night. Everyone is working hard and we are effective in every aspect of the game-the power play, penalty killing, scoring, defense."

Potvin credits Arbour, a pretty good pro defenseman whose trademark was his glasses, with turning him from a rushing junior into a allround NHL defenseman.

"Thanks to Al, I have learned to play defense the right way while still retaining my value as an offensive defenseman," Potvin said. "I don't worry about points anymore. I worry about things on a game-to-game basis."

It is the Capitals, winless in 19 previous meetings with the Islanders, who are likely to be worrying tonight.