MUHAMMAD ALI did it. Michael Jordan did it. Twice. Ted Williams did it. Twice. Mike Tyson came apart trying. Kim Clijsters? Oh, mama! Floyd Mayweather did it impressively on the weekend, against an undersized, overmatched warrior.

And now it is Michael Vick's turn to peer into the comeback kaleidoscope, first time in a long time. Do the multicolored crystals align in a starburst pattern or do they wind up in the random, chaotic design that spells failure?

Vick missed two NFL seasons doing time in the slammer for behavior Jeff Lurie described as lacking "a shred of human decency." And now Vick comes back with the Eagles, owned by Lurie.

Does pro football make strange bedfellows or what? After an exhibition charade, Vick bragged that "the sky's the

limit." How high the sky? We will have a better idea starting Sunday, when Vick is activated for his first meaningful game in 3 years. What does history tell us about his chances?

Let's start with Ali, a very good place to start any noisy debate. On April 28, 1967, Ali refused to take that one step forward at an Army induction center in Houston. That very same day, the New York State Athletic Commission stripped Ali of his title and snatched away his boxing license.

Other states followed. For 3 years, for chump change, Ali delivered clumsy speeches to college kids. He appeared briefly on Broadway in "Big Time Buck White." People worked feverishly to get him a fight, on an Indian reservation, on a barge beyond the 3-mile limit, in Pennsylvania ("Over my dead body," snarled commissioner Chuck Bednarik).

Even before the Supreme Court reversed Ali's draft-evasion conviction on a technicality, Ali was permitted to fight Jerry Quarry in Atlanta in October 1970. Showed glimpses of those swift hands and dancing feet, stopped Quarry on cuts in the third round.

Beat Oscar Bonavena 2 months later. And then signed to fight heavyweight champ Joe Frazier in Madison Square Garden on March 8, 1971. Fought brilliantly, courageously, but Frazier was too strong, too determined, flooring Ali in the final round with a left hook that came whistling out of Beaufort, S.C. Joe won a unanimous decision.

Along the way, Ali somehow got the image of antiwar crusader and civil-rights activist. Which had to tickle the charismatic fighter who once declared, "I don't have to be what you want me to be."

In Zaire, of all places, Ali bewitched, bothered and bewildered George Foreman, rope-a-doped him, knocked him out in the eighth round, regained the heavyweight championship in October 1974.

After that, it was a rattling roller-coaster ride that mirrored Ali's shortest poem, "Me? Wheee!" Beat a bloodied Chuck Wepner to inspire Sylvester Stallone to write "Rocky." Beat guys named Coopman and Dunn. Collected a tough payday against a shin-kicking wrestler named Inoki. Lost the title to Leon Spinks. Got it back from Leon Spinks. Retired. Came back, foolishly, and was pounded by Larry Holmes.

Apples vs. oranges? Boxing is an individual sport; football, to almost everyone not named Terrell Owens, is a team sport.

Let's move on to basketball and Michael Jordan, the best player to ever play the game. Jordan won three NBA titles with Chicago in '91, '92 and '93. And then walked away, which is ironic, because they never, ever called walking on Jordan.

He wasn't old or injured. He had just won his seventh scoring title. In the finals against Phoenix, he averaged 41 a game. Got the MVP bauble for the third time.

He quit to play minor league baseball. Said he was honoring his father, who had been murdered at a highway rest stop. No one pursued the rumors that the league had asked him to step aside to deal with a compulsive-gambling problem. Spent a year trying to hit the curveball in Birmingham. Batted .202.

And then, in March of '95, he issued a two-word proclamation, "I'm back." Scored 55 in a game against the Knicks, but the postseason ended in a loss to Orlando.

Won it all the next year, scoring title, MVP, the championship on Father's Day, tearfully. Won it the next 2 years, shoving that Utah player aside to make one incredibly clutch, indelibly photogenic shot for the ages.

Retired again in January of '99. Came back again in 2001 to play for the Washington Wizards, filling arenas, scoring 43 in a game at age 40. His final game was April 16, 2003, in Philadelphia, scored 13, got a standing ovation.

Quit for good, found a home in the Charlotte Bobcats' front office, worked on his Hall of Fame acceptance speech. Should have worked harder.