An exhaustively researched book chronicling Barry Bonds’ long-term steroid use written by San Francisco Chronicle reporters Mark Fainaru-Wada and Lance Williams will hit the book stores on March 27. Sports Illustrated has released excerpts from the book in its current issue, and to say they are damning would be an understatement. It would be an overstatement, however, to say that they are surprising. The evidence that Bonds used performance-enhancing drugs to transform himself late in his career from simply a great player into a freakishly great player has been growing, like Bonds himself, with each passing year, and “Game of Shadows” just moves the marker from 99% certainty to 99.9999% certainty. In other words, certain.

Bonds used illegal steroids. Bonds cheated.

Yet still, on sports talk shows and in sports columns, ethically confused individuals keep saying and writing that such a conclusion isn’t “fair” to Bonds. “He’s innocent until proven guilty,” they say. “This is America,” they point out.

They are correct about the locale, but are otherwise mistaken. The much-quoted “innocent until proven guilty” standard, which is not in the Constitution or Declaration of Independence, is simply a convention that establishes that the State has the burden of proof before a criminal sentence can be imposed on a citizen in court. Nobody is talking about putting Bonds in jail (yet) , and Major League Baseball must have an investigation and a hearing before it takes any job action against him. That doesn’t mean that it “isn’t fair” to Bonds for thinking people to make reasonable conclusions based on what is known, which includes, but is not limited to, the following:

• At an age when virtually every other player in major league baseball history has begun to decline in offensive skills, Bonds’ ability to hit a baseball increased dramatically.
• Contemporaneous with a sudden improvement in strength, Bonds’ physique changed at a rate and in a manner characteristic of athletes who use steroids.
• His personal trainer and childhood friend, Greg Anderson, supplied steroids to his other clients and is a known steroid dealer and user.
• Bonds was closely tied to BALCO, a supplement company heavily involved in providing steroids to elite athletes.
• In leaked grand jury testimony, Bonds explained evidence linking him to steroids by claiming that he had been given steroid products without his knowledge by Anderson.
• Bonds’ mistress has publicly stated that Bonds injected steroids in her presence.
• Bonds’ earlier statements that he “never” used steroids were contradicted by his grand jury testimony. Subsequently, his stance has oscillated between denial, rationalization, defiance, silence, and claims of victimization.

Now, on top of all this, “Game of Shadows” documents Bonds’ steroid program with more than a thousand pages of materials collected by the authors, including transcripts of grand jury testimony and a mass of documents relating to the BALCO investigation; memos, secret recordings, taped phone messages, and more than 200 interviews. Sports Illustrated, a prestigious magazine in its field not given to publishing accusations that it can’t back up, doubtlessly had its legal staff review the material thoroughly. If untrue, the story would be worth mega-millions to Bonds in a liable suit and destroy S.I.’s impeccable reputation. But the magazine has published it. And Bonds isn’t going to sue.

It is as fair to Bonds to conclude that he is a steroid-user as it is to conclude that Natalee Hollaway, Jimmy Hoffa, and Amelia Earhart aren’t sharing a condo somewhere in Tahiti. As fair as it is to Al Capone to conclude that he was a mobster, killer and rum-runner, and not, as he claimed, just “a business man” who happened to get on the I.R.S.’s bad side. As fair as it is to decide that O.J. Simpson is someone you wouldn’t want to meet in a knife factory; as fair as it is to make a policy decision not to buy a used car from James Frey. If all the evidence in “Game of Shadows” that Barry Bonds has used steroids was presented in court before a competent jury, he would be found guilty beyond a reasonable doubt, because there is no reasonable doubt.

What is the right thing for Major League Baseball to do? Review the evidence, have a hearing, and end Bonds’ career now, to protect the integrity of the game or what little of it there is left where Bonds’ records are concerned. That would be eminently fair, and far, far fairer than Barry Bonds has been to his sport, his team, his competitors and his fans.