In New York, the mayor's office has a plan to stage a tickertape parade for the Rangers, should they win the Stanley Cup. There is no such arrangement for the Islanders, who were joking Thursday about the possibility of a three-day motorcade from Riverhead on Flanders Bay to the New York City border in Queens.

A few hours later, the Islanders' Stanley Cup prospects were no joke. The National Hockey League's top team during the regular season had been completely outplayed by the Rangers, who had finished 25 points behind and were still nursing the wounds from their physical quarterfinal conquest of the the Philadelphia Flyers.

The Rangers won, 41, while building a 38-22 advantage in shots. The Islanders were denied skating room by the close-checking Rangers and their high-powdered scoring attack fizzled. Mike Bossy, a 69-goal man, did not fire one shot at the Rangers' John Davidson.

Few thought the Rangers capable of such an effort. Now the big question in the Big Apple is whether they can do it again. And, for a change, all New Yorkers will have the opportunity to find out this afternoon, as game two is aired by the NHL network (WDCA-TV-20 at 1 p.m. in Washington).

Fans paid up $150 per ticket, face value $18, at Nassau Coliseum Thursday, as that night's game and all others except today's were kept off home TV because of the clubs' cable commitments. Attempts by state legislators to force telecasts by WOR-TV-9, the normal outlet for both teams, did not succeed.

The Islander fans sat in disbelief for a while Thursday, then turned on their heroes, greeting routine saves by goalie Chico Resch with derisive cheers and reserving the same treatment for rare Islander shots, of which there were three in the second period.

We didn't play very smartly, didn't do anything well,' said Islander Coach Al Arbour. "We were doing everything backward. Thank God, it's a seven-game series."

Knowing the Rangers to be subpar physically, the Islanders apparently expected an easy time. Howevery, the Rangers assistant coach, Mike Nykoluk, pointed out that "we have an awful lot of young kids. They may have been tired after Tuesday, but they've got the legs."

Ranger fans were noticeable at Nassau Coliseum, enjoying themselves. They chanted "J.D." after Davidsons more difficult saves and they stood outside in the rain for 90 minutes for a chance to pat their heroes on the back.

The other semifinal resumes in Montreal tonight, with Boston one game down after a 4-2 defeat Thursday. The Bruins have lost 12 straight in the Montreal Forum.