Near the end of her NBC special "Ol' Blue Eyes and Ol' Brown Eyes," gossip columist Suzy Knickerbocker asked Muhammad Ali to give her a little tap on the chin so she could tell her grandchildren that she had taken a punch from the heavyweight champion of the world.

Ali declined and kissed her instead. That was a mistake. The request should have come earlier in the hour and Ali should have decked her, thus sparing all of us the misery of having to sit through this total waste of an opportunity to get some fresh insights into the character of Ali and Frank Sinatra at an interesting time in both their lives.

Suzy (her real name is Aileen Mehle) is no fool. She moves around a lot and knows a great deal about the private lives of the people she writes about in her column. And she has entree. She can get people like Sinatra and Ali to agree to an interview.

Sinatra is more difficult to get than Ali. He feels, and often with more justification than reporters would like to admit, that he has been burned by the press. So he does not grant interviews readily.

Whatever one may think of the man, Sinatra has been a major personality in show business for nearly 40 years. For a lot of reasons the rest of us can only speculate upon - the death of his mother in a plane crash and a marriage that seems to have provided him with tranquility and a softer edge to his personality - Sinatra seems to the outsider to be moving into a new phase in both his private and professional life.He seems willing to talk about where he has been and where he is going.

There was a moment in the interview when Suzy said: "Frank, you once said about yourself. 'I have been an 18-karat manic-depressive. I've led a life of violent emoitional contradictions. And I have an over-acute capacity for sadness. Now do you feel that way?

Frank: "No."

Suzy: "I'm glad."

Frank: "No, no, that's all-eh . . . that's all gone."

Suzy: "That's good. And that's maby be the reason over there. That beautiful blonde."

Sinatra then went on to say that while his wife had helped - had, as the put it, "finally put the icing on the cake - he had really worked out the problems on his own.

He then talked in a rather fascinating way about sleepless nights when he would use anything to get him through the night: "Jack Daniels, aspirin, or a prayer, or something . . ." He was about to take off on his won, and the smart thing would have been to get out of the way and just let the man go on. Not Suzy. She broke it off by posing a question to Barbara Sinatra. The moment was lost.

Suzy didn't do nay better by Ol' Brown Eyes than she had done by Ol' Blue Eyes. At one point she asked Ali why children loved him so much. He answered: "Well, children are exiles from heaven. Like an infact has the riches of God. And I just love children and they can feel it."

Rather nice, right? Rather poetic. And how did Suzy follow up on it? Here's how; "Ali's a fighter, but he's deeply religious. He loves children. The fact is he's angry only when he's pretending." Another moment for some fresh insights cast away.

The next question might have been why Ali also appealed to teen-agers and college students. There was a time during the late '60s when Ali was just about the only person college students respect. Teen-agers, to judge the reaction when he appeared on television in my household, expressed the admiration and delight usually reserved for the Smothers Brothers and Johnny Carson.

Why did Ali have the appeal? And is he in danger of losing it by sticking around too long? Well, Ali, who knows a story line the way he knows a tentative left lead, wanted to keep talking about it. But Suzy wouldn't let him.

The normal of all this is that we now seem to be entertaining an era of television interviewing when the interviewer gushes instead of asking questions. This is especially true when the person being interviewed is very famous and in some branch of entertainment. Because it is so awful, I an sure that the gush school of interviewing has a bright future.