Hockey fans are eagerly awaiting two matchups in the Stanley Cup playoffs. One, of course, would be a climactic encounter between the Montreal Canadiens and New York Islanders. The other starts tonight in Philadlphia, between the Flyers and the New York Rangers.

The catalyst in this dream series is Fred Shero, winding up his first season as boss of the Rangers after seven years in Philadelphia that included the only two Stanley Cup titles achieved by an expansion team.

Shero quit the Flyers in May, citing a lack of enthusiasm for hockey. Two weeks later, his enthausiasm returned and he moved to New York, where there has been no problem psyching up players and fans for each battle with the Flyers.

In the clubs' first exhibition, the Rangers went into Philadelphia and were thumped, 8-2. A few nights later, in New York, the teams thumped each other for 25 minutes, resulting in 12 ejections, $5,200 in fines and those time-honored warning that the NHL will not stand for such actions.

Once the regular season started, the confrontations included Ranger Carol Vadnals' spearing of Flyer Paul Holmgren, with a subsequent Holmgren two-hander over the head leading to a six-game suspension and more league recriminations.

In eight regular-season meetings, the Flyers won three, with three others tied. Both Ranger victories came in Philadelphia, as New York three times was unable to hold huge leads in Madison Square Garden.

In the teams' last regular-season duel, in Philadelphia on April 1, the Flyers breezed, 7-3, to virtually assure the extra home game, for what it is worht, in this series.

Ranger goalie John Davidson was superb in two preliminary victories over Los Angeles, but there is something about those Flyer uniforms that turns him to jelly. The Flyers, without Bernie Parent, are erratic in the nets and have no hope of regaining the Cup, but they should win this series.

The last time the teams met in a playoff, the Flyers prevailed in a seven-game semifinal in 1974, before beating Boston for their first Cup triumph. In the process, a Bobby Clarke elbow shattered the jaw fo New York's Walter Tkaczuk. His series, with all the fallout from Shero's switch, should be equally exciting and, despite those NHL protestations, probably as violent.

Fans with keen ears and good radio reception can follow the action on 610 or 1130.

The other quarterfinal series, all best of seven, shape up like this:

Chicago at New York Islanders

The Hawks have a great goaltender in Tony Esposito and he is capable of stealing a game or two. There is no way Chicago can win four from the powerful Islanders, although it was able to take two of five during the regular season.

Both teams have enjoyed a week's layoff, earning preliminary-round byes as division champions. Chicago, the Smythe winner, would not have placed fourth in the Islanders' tough Patrick company, however, and it can hope for no more than to break its record string of 12 playoff defeats, dating back to 1975.

Toronto at Montreal

The Maple leafs have not beaten Montreal in their last 16 games, including a semifinal sweep a year ago. That series provided Canadian fans with the first postseason matchup of the teams since 1967 and here they are again, with Toronto somehow hoping to equal it s1978 quarterfinal success against the Islanders.

The Leafs swept Atlandta in the preliminary round, but if Coach Roger Neilson's job truly depends on toronto reaching the final, he had best start filling out some applications for work. Although the Canadiens have slipped a bit, they have too much depth for Toronto.

Radio: Rest your college French on 690. If you're an Anglohone, spin the dial and hope for something besides static.

Pittsburgh at Boston

On the Penguins' last visit to Bost Garden, they posted a 3-1 victory that raised their overall record in that pit (forgive the pun, it's been a long season) to 2-27-2. The previous success came on Jan. 28, 1968.

Pittsburgh took the season series, 2-1-1, and has been a potent club through the second half of the season, save for that last waltz at Capital Centre April 8. Randy Carlyle and George Ferguson, two acquisitions from Toronto, have been outstanding and goalie Denis Herron held off hot-shooting Buffalo in the preliminary round.

Boston was delighted to see the Penguins oust Buffalo, a team it could not handle. Pittsburgh will not be easily handled, but that week's rest has helped the Bruins considerably, especially defenseman Brad Park, who was virtually immobile at regular season's end. Boston should make it to the semifinals, no farther.

Radio: 1020, if the Pirates aren't playing.