Duane Bobick, who was been trying to regain his creditability in the ring ever since he was knocked out in the 1972 Munich Olympics by Teofilo Stevenson of Cuba, gets his big chance Wednesday night.

Bobick will face Ken Norton, the top-ranked contender to Muhammad Ali's heavyweight title, in a 12-rounder at Madison Square, Garden.

NBC (WRC-TV-4) will begin its telecast at 9 p.m., with the features match scheduled to start sometime after 10 p.m.

Although unbeaten in 38 professional fights, Bobick has not been regarded as a serious challenger because most of his opponents have not been high-caliber fighters. The powerful Norton, who lost a controversial decision to Ali last September, is an 11-to-5 favorite.

Norton scaled 222 3/4 pounds to Bobick's 215 1/2 at today's ceremonial weigh-in. Both have spoken of the fight being a steppingstone to a championship bout with Ali, taking for granted that the titleholder will have no trouble with Alfredo Enganelista Monday at Capital Center in Largo Md.

George Foreman, at least temporarily, is out of the title, having announced his retirement aften an upset loss to Jimmy Young. Curiously, neither Norton nor Bobick has expressed any interest in fighting Young; nor has Ali, who won a disputed decision over Young on April 30, 1976, at Capitol Centre.

Bobick has tried to play down the image of being another "Great White Hope," particularly since Frazier owns his contract; Eddie Futch, his manager of record, Murphy Griffith (uncle of boxer Emile) and Georgie Benton of his camp are all black.

But there is no question that the racial aspect is part of the attraction of the bout. That is why Ali says he wants Bobick to win, envisioning a big gate.

Norton's best hope of winning is to put Bobick away early or to exploit the Minnesotan's susceptibility to cuts. Norton is a sharp if not paralyzing puncher. Bobick figures to give him trouble by crowding him, not giving him punching room, and sapping his energy with body punishment.

Norton is said to have caught Ali out of condition in March, 1973, when he decisioned Ali and broke Norton five months later and appeared to be given the benefit of being champion when he was awarded a decision over Norton last Septmeber.

NBC will announce the scoring by the refree and two judges between rounds as well as at the finish. Fortunately, for the ring officials, the round-by-round results will not be made known in the Garden.

The network is making another departure from custom by not blacking out New York City. NBC executive vice president Al Rush said last week, "We expect big ratings."

The wonder is how the Garden can pay Norton $500,000 and Bobick $250,000 and still show the fight on home television.

A source close to the promotion suggested that NBC had agreed to pay the Garden for empty seats up to nearly 80 per cent of capacity, for the privilege of guaranteeing sponsors exposure to New York's 8 million population.

Mike Burke, president of the Garden, was asked if he were not taking a financial risk. He had said the Garden was scaled to do only $500,000 at the gate if sold out, with seats going at $50, $30, $20 and $10.

Burke said there was no such underwriting of seats by NBC. "We bought the fight and sold it to NBC. We won't get killed financially because we got a good-enough contract from NBC so we won't."

Rush would not say how much NBC paid the Garden, nor would Burke. But another source said it was $1.3 million.

A spokesman for the Garden said there was about $150,000 in advance sales by Friday. By Monday, most of the top-priced seats were sold. The Garden is hoping for a crowd of about 10,000.