Charles Dickens' novel A Tale of Two Cities begins with: "It was the best of times, it was the worst of times."

He was writing, of course, about the years leading up to the French Revolution. But he could have been describing professional sports in America today.

Unless you've been locked up for months in a modern-day Bastille, you're undoubtedly aware that several of the professional leagues face controversies that cut to the very core of their credibility.

Major League Baseball's most prestigious statistic, the career home run record, held by Hank Aaron, is in danger of being eclipsed by San Francisco -Giants slugger Barry Bonds, who is alleged to have used performance-enhancing drugs.

What should be a baseball celebration has turned into major league hand-wringing over the validity of Bonds' claim to the record. Sportscaster Bob Costas described Bonds' accomplishment as "clearly inauthentic." When told of Costas' comment, Bonds dismissed it by calling the 5-foot-6 1/2-inch Costas a "midget." Maybe so, Costas retorted, but "unlike some people, I came by all of it naturally."

The National Basketball Association was hit with revelations stemming from an FBI investigation that one of its referees, Tim Donaghy, allegedly bet on NBA games and possibly disclosed confidential information to gamblers. NBA Commissioner David Stern somberly addressed the media about the allegations and characterized Donaghy as a "rogue, isolated criminal." Meanwhile, the rest of the league has been holding its breath until it's confirmed that no other referees are involved.

The National Football League continued to battle image issues with news of the indictment of one of its star players, quarterback Michael Vick of the Atlanta Falcons, for his alleged - there's that word again - involvement in a dog-fighting ring. This week, one of Vick's co-defendants in the case said in a plea bargaining agreement that Vick bankrolled the operation and bet on dog fights at a Virginia property he owned. NFL Commissioner Roger Goodell responded to the incident by ordering Vick to stay away from the Falcons' training camp, and Vick merchandise has been pulled from stores and Web sites around the nation.

In response to this trio of controversies, a burning question in the sports and business media has been, "Will these incidents permanently affect the leagues' popularity?" The reflex response is, "Of course they will!" But how?

Foxsports.com columnist Mark Kriegel suggests convincingly that the history of sports in this country is riddled with ugly incidents and bad apple athletes-and that sports fans shrug them off and come back hard for more. He cites sordid activities ranging from point shaving, gambling on games, substance abuse, assault, rape and mob connections.

"It's always been a cesspool," Kriegel writes. "And that's one of the reasons you care."

He goes on to argue that the controversies in sports may actually be a big part of their appeal.

"The great con in sports is this idea of the good old days. . . . Every year it gets worse. And every year, you want more."

Kriegel's blunt comments have the aroma of truth and suggest an answer, albeit a cynical one, to the burning question posed earlier: These controversies, as distasteful as they may be, are a temporary takedown for the leagues and their respective sports. They're a blip that will be erased by our collective obsession with our favorite teams and the stars that play for them. Ultimately, they'll be replaced in our consciousness by the impact of yet another round of controversies that threaten (but eventually fail) to rock the world of sports.

The Bonham Line: The American love affair with sports is remarkably resilient. Like our insatiable national appetite for celebrity nonsense, we can't get enough of sports, no matter how unsavory the latest incident might be. There's always another game, another season, another star. And we will all be there to cheer or boo, but never to ignore.

Dean Bonham is CEO and Don Hinchey is VP of communications for The Bonham Group, a Denver-based sports and entertainment marketing firm. Send your comments to dhinchey@bonham.com.