The new name in boxing is Mike Tyson. He is reviving interest in the moribund heavyweight division, a fresh face among that clump of retreads.

He has won all 21 of his professional fights, 13 of them by one-round knockouts, and fights again Friday night at Madison Square Garden against Reggie Gross of Baltimore.

Tyson is 19 years old, and his announced schedule calls for him to win the heavyweight title by May 1987 and become the youngest champion in history. His muscles bulge. He is just under 6 feet and has a 19 1/2 neck. He is a slugger who demolishes those who stay in his way too long. He is the hottest property in boxing, the darling of Home Box Office, which, almost sight unseen, paid him $1 million for three fights. ABC also has rushed in with a big contract.

The Mike Tyson story is an engaging one. He came off the street in Brooklyn, where he was a young thug. He graduated from petty thefts to picking pockets and then to stickups. At 13 he was jailed and at 14 paroled, given into the legal guardianship of the late Cus d'Amato, boxing theoretician and operator of a gym above a New York police station in the Catskills.

With d'Amato, he found his element. No more robbing people and such. He wanted to be a fighter, and for four years with d'Amato, it was an internship in the art of sock.

His list of speedy knockouts served to launch Tyson like a fistic rocket. Promoters everywhere are scrambling after him, and he has acquired two managers, Jim Jacobs and Bill Cayton. Jacobs, wise in the boxing business, has orchestrated a gee-whiz publicity campaign for his Knockout Kid unrivaled by that for any other young fighter, and imputing that the title is just around the corner.

And now for the other side of the Mike Tyson story. What a pity he can't fight very well.

Tyson is a clumsy novice who has been spoon-fed selected opponents, and his hype has been outrunning his merits as a threat to anybody's title.

He still lacks too many tools. Tyson's favorite modus operandi is to rush off his stool and whale away at the other party. If his opponents don't crumble, Tyson is in trouble. If they move and have mobility, he is in worse trouble. He has no jab, can be tied up easily by any savvy boxer, and is easy to hit. All of this was seen in his last two fights, which went the distance.

As for all those rapid victories in his first 19 fights, one authoritative boxing figure, who would like anonymity because of a slight conflict of interest, had this to say of Tyson:

"He has been knocking out bums who have been knocked out by other bums."

As for Tyson's boxing ability, the same observer commented: "He don't know zig from zag."

Whatever aura of invincibility Tyson was beginning to acquire began to unravel in those last two fights, won by 10-round unanimous decisions. Tyson -- who once could boast that in one span of five of his first-round knockouts, he spent a total of less than five minutes in the ring -- hasn't knocked out anybody in 20 rounds now.

He showed he hasn't learned how to fight 10-rounders, spending himself early and then showing fatigue. James Tillis and Mitch Green, his last opponents, are at best journeyman heavyweights of no surpassing skills, but they knew how to handle Tyson and his indiscriminate flailing. Just don't stand there.

Tillis and Green moved on him and defused all his bombs. They weren't winning, but the knockout bubble was burst, and they were exposing Tyson as a fighter who could be tied up easily, who didn't know defense from brussels sprouts and had much to learn about the boxing business. They were confirming suspicions about the types Tyson had been licking in earlier bouts. They were too fatigued to hurt Tyson in the later rounds, but better-conditioned fighters would have hammered him.

A commentary on the types of opponents selected for Tyson in his earlier bouts was offered in January by the New York Times' Phil Berger after Tyson scored his 17th knockout, a five-round affair with Mike Jameson:

"At 6-4, 236 pounds, Jameson is a jiggly slab of a man with drooping pectorals and rolls of fat protruding from his waistband. He was in no shape for the kind of pressure Tyson applied, and his record fell to 17-10." This guy stayed with Tyson longer than anybody else up to then.

Tyson weighs 215, and in addition to his knockouts, he has been an eye-catching figure by refusing to wear socks or robe into the ring, against all tradition. He has bantered with David Letterman on the late show, makes no protest of his managers' ambitious schedule for him that calls for two fights a month (silly), and after every fight dutifully returns home to his pigeons ("Pigeons don't ask me for money; don't ask me for favors.").

If the Tillis and Green fights could be excused as the kind of missteps that even great fighters have known -- Ali barely got by Doug Jones and Louis took that awful beating from Max Schmeling -- then Tyson is not to be ignored. But all the evidence suggests he was fighting up to his capacity.

There is no cause to quibble with Tyson as a puncher or a person. His rehabilitation from thievery has been admirable and complete. With his 21-0 record, he is a true boxing sensation, until somebody licks him. But his path to his planned conquest of the heavyweight title could be more rugged than he suspects.

Those who stand in his way, though no giants of the profession, have certain important skills that he lacks. Pinklon Thomas would confront him with the best left jab in the business and move and stab him at will. Tim Witherspoon, given the same opportunities Tillis and Green had, would punch him out. Boxer-puncher Trevor Berbick would delight in Tyson's presence in the ring.

If he came back, Larry Holmes would hurt him worst. And in the ring with the present champion, the savvy, ubiquitous Michael Spinks, well, Tyson wouldn't know where to find him.