Michael Spinks hangs around the ring like some bored kid on a street corner, waiting for a bus to throw a rock at.

Spinks won't dazzle anyone with his style, and he won't necessarily bother anyone with his errant lefts and rights, and he doesn't invite controversy like Larry Holmes. But the 29-year-old boxer with the carefree mien and the unbothered expression has marquee value just the same, and he has Holmes' title, still.

For the second time in seven months, Spinks has sent Larry Holmes, 36, into retirement. He retained his International Boxing Federation world heavyweight title Saturday night with a bitterly narrow, 15-round split decision over the tired former champion, who says he has had it with the whole mess.

Spinks' victory at the Las Vegas Hilton duplicated his feat of September, when he won a decision over Holmes to become the first light heavyweight to dethrone a heavyweight champion. What Holmes, not surprisingly, refused to admit on both occasions was that he may have been beaten by a curiously talented young champion.

Spinks, at 205 pounds, is rapidly gaining recognition as one of the smartest, most oddly difficult of opponents, regardless of his division. He retained his title with a late two-handed attack after an intimidatingly hungry Holmes, who held his title for seven years until September's defeat, had taken the first five rounds clearly.

"I knew he would be aggressive for only so long, and then fatigue would settle in, as it always does," Spinks said. "That was the plan, to let Larry think he was having a great night. Then to catch up and pass him."

Holmes had predicted that he would knock Spinks out in seven rounds and his intentions were obvious from the opening moment, when he rushed Spinks against the ropes, then threw him to canvas. But Spinks has an uncanny talent for survival; he continued to wait Holmes out, apparently willing to let the challenger have the first few rounds. It is becoming a trend in his career, in which he is 29-0.

"I was there for whatever Larry wanted to do," Spinks said. "Wrestling, football tackles, whatever. I said I'd go with the flow. If he wanted to throw me down, I would go down, roll over, then get up and start again."

Spinks' victory over Holmes was not as important historically as his September bout. But it did show that he could defend his title to those who do not yet consider him a true champion in his new weight division.

To gain that respect finally, however, he will have to show that he can defeat a much younger, stronger challenger than Holmes. His next fight, according to manager Butch Lewis, probably will be in September against the winner of a meeting between Gerry Cooney and Eddie Gregg. That fight is scheduled for May 31 in San Francisco.

According to his critics, Spinks lacks strength and power, and he did not convince anyone otherwise Saturday. He never appeared to seriously shake Holmes; rather, he simply endured him. His strategy may contribute to the reputation he is acquiring of not being a particularly hurtful boxer.

"Michael never hurt me," Holmes said. "Not once. He didn't really do anything."

But his elusiveness and awkward style make him hard to contain in the ring. Even Holmes admits that. One thing that makes Spinks difficult is that his methods seem to change constantly; he rarely fights the same type of bout twice, just as he rarely makes the same moves. He combines that with a way of conveying an impression of doggedness; he seem to constantly be on the edge of a knockout, only to escape.

"He's never really there," Holmes said. "It's hard to put two punches together against him."

It is precisely that style that may deny Spinks respect for the moment; he is still regarded as an oddity.

"Style makes boxing," Spinks said. "I'm the type who adjusts to the style in front of me. I had to fight Larry the way I did."

As for the contentious Holmes, he had made a retirement announcement after his last loss to Spinks, only to retract it. This time, Holmes stated his intentions to retire with a cry of frustration that encompassed every facet of organized boxing, which he said had united against him.

"Who ever expected Larry Holmes to get a fair shake?" he said. "Especially when I'm always saying things. There ain't no sense in chasing ghosts. What I say this time will hurt me, what I say next time will hurt me. I've got a big mouth, and I got my hand slapped for it. This is it . . . For the first time, I cried."

There were many who scored Saturday's fight for Holmes, who is 48-2. And there were many, like Holmes, who think that perhaps his mouth finally caught up with him.

Recently, he had remarked that he thought Nevada judges came to fights drunk. Following the September fight, when Spinks stopped him from tying Rocky Marciano's record of 49-0, he said that Marciano "couldn't carry my jockstrap."

His postfight performance this time was similar. He spoke at length from his hotel suite, nearly four hours after the fight, following a visit to a local hospital where he was treated for a broken right thumb apparently sustained in the third round. Among those he indicted in his scathing remarks were all promoters, all judges, the World Boxing Council and the IBF.

On the fight: "If Michael Spinks spoke the truth he'd say: 'I don't want this belt because Larry Holmes kicked my butt.' "

On the IBF: "I made the IBF and I can break it. I don't care what I have to do. I thought it would be different, but it's not . . . I know all the ins and outs of boxing, who does what to who. They don't like that."

Finally, on his career: "I haven't regretted anything I've done. I've regretted some things I've said."