Tiger Woods has it. So does Arnold Schwarzenegger and George Clooney. Mickey Mantle certainly had it. And Magic Johnson still does.
It's charisma, and you can't manufacture it, bottle it or buy it. It seems you're just born with it.
David Beckham had it in his native England. But is it transferable to America? And, if it is, does he have enough of it to outshine other mega-celebrities in L.A. and lift the fortunes of an entire sport that Americans never have completely embraced at the professional level?
Pele, perhaps the best soccer player the game has ever known and a charismatic figure, couldn't do it.
He arrived in the United States in 1972 amid much hoopla. Three years later, after he led the New York Cosmos to a North American Soccer League championship, Americans saluted his effort and talent. Then they got back to watching baseball, football and basketball.
Time will tell with Beckham, who makes his American debut with the Los Angeles Galaxy at a practice Monday. But there are reasons the 32-year-old midfielder could succeed that have nothing to do with soccer: He's handsome, he's got a celebrity wife (Victoria "Posh Spice" Beckham) who seeks and attracts attention, and he's got endorsements that will put his image in front of Americans regardless of whether they ever watch him play.
He's already had his name in Hollywood lights. The 2002 movie "Bend it Like Beckham" put his name on Americans' lips even if they weren't sure who he was and what he bends.
The movie and Beckham's wife make him recognizable to many Americans who don't follow soccer. Leo Braudy, a USC English professor and expert in pop culture trends, says that increases the chances Beckham's charisma will become a "radiating force" in the U.S.
Dr. Joyce Brothers, the celebrity psychologist, sees other things working in Beckham's favor.
"We've reached a point now where women will say they like looking at attractive men," Brothers says. "If he gets along with all the guys and he makes all the women swoon, then he's got it all."
Still, charisma is more than just looks and personality. Though few seem capable of defining it, let alone explaining why some people have it and others don't.
We know Michael Jordan had it. So did Mantle while his teammate, Roger Maris, never did, even though it was he - not Mantle - who broke Babe Ruth's single-season home run record.
Muhammad Ali, even as a frail, 65-year-old version of the brash, young boxer he once was, still has it.
When it's strong enough, Braudy says, people who don't care about what you do still will care about you.
But that's difficult to maintain, particularly for athletes.
Hollywood actors have publicity machines behind them and their careers can be carefully managed to ensure the persona that brought them fame never fades.
Athletes also get help but, ultimately, they have to perform and all the managing in the world won't return the luster after a series of strikeouts in the World Series, dropped catches in the Super Bowl or missed shots at the buzzer.
Sports marketing expert David Carter says Beckham and the Galaxy, who are paying him a Major League Soccer-record $5.5 million this season, are taking a risk.
"What if he gets hurt? What if he does not help impact the Galaxy's winning percentage?" he says.
Still, Carter believes Beckham likely will deliver enough of a boost that his team will fill stadiums around the country and its star player's image will sell plenty of T-shirts, shorts and shoes.
UCLA sociologist David Halle, a native of England who has followed Beckham's career, believes Americans will be attracted by the dignity and humility with which he says Beckham carries himself. Even when much of England angrily blamed Beckham for losing a shot at a World Cup title in 1998 by drawing a penalty, he says, the athlete didn't appear to let it bother him.
"He's not a whiner," Halle says.
But it's more than that, says Laura Bahr, a Los Angeles actress and screenwriter.
"It's this star quality. Some people have it and some don't," she says. "It's about this ability to connect with people on various levels."
Like so many other Gen Xers, Bahr grew up playing soccer but abandoned it in adulthood. Beckham has her interested again. He seems kind, unselfish and, at least as far as she can tell from TV interviews, not as ego-driven as most star athletes. Add his looks and it's a given she'll be cheering for the Galaxy this year.
"With a face like his, how couldn't I."