The timing would be perfect. It's a dead zone in the sports schedule. He wouldn't be distracting from anyone else's glory, except perhaps the models in the Sports Illustrated swimsuit issue. He couldn't be accused of cynically lobbying for a place in the Hall of Fame, whose voters have resoundingly rejected him in his first three years of eligibility. The next round of balloting would be a whole 10 months away.

Above all, seven years have passed since McGwire retired from baseball. Regardless of what he might have ingested to enhance his career, he can't be prosecuted for it now. Every applicable statute of limitations has expired.

If he used steroids or growth hormone, he has nothing to fear from speaking up. His reputation can't suffer. As it stands now, his baseball legacy is not 583 career home runs or 70 homers in that magical 1998 season, when Roger Maris' sons embraced him as the heir to their father's record. It's: "I'm not here to talk about the past."

His evasions at the Congressional hearings on performance-enhancing drugs deserved every bit of the ridicule they received, but under the right circumstances, they could easily be forgiven. Jason Giambi, McGwire's protege a dozen years ago in Oakland, is proof that people will get over a player's doping if he reaches even the vicinity of truth and contrition. They don't even demand a full accounting. They just want a vague mea culpa and an apology. It's certainly not a game of inches.

Still, McGwire seems likely to cling to silence forever. In his opening statement on Capitol Hill, he said that players couldn't win either way. If they said they didn't use, no one would believe them. If they said they did dope, they'd risk "public scorn and endless government investigation."

At this point, though, the public scorn can't get any worse. He can't alienate people who believe he was clean, because they don't exist. McGwire's biggest defenders are, at best, apologists. They'll say that there's no absolute proof and that the stuff wasn't banned in baseball when he played anyway. (Steroid use without prescription was, however, illegal in the real world.)

But the best defense for McGwire has nothing to do with the slippery ethics of doping. It's the fact that he didn't commit perjury. Whatever grandiose vision he might have about himself, he didn't have the gall to lie under oath, thinking that people would just believe him because of who he is.

Contrast that with Roger Clemens, whose Congressional appearance included the following: A. A defense about growth hormone used at his home that shifted the blame to his wife, who apparently wanted to look hotter than usual while posing for the SI swimsuit issue, B. Discussion of a supportive call he received from the elder President Bush on a duck-hunting trip, and C. Borderline hysteria over Andy Pettitte's incriminating statements.

In fact, Clemens' "he mis-remembered" line has more staying power than McGwire's aversion to talking about the past, because it can't be erased and because some wag Photoshopped a picture of Pettitte, adding a beauty-queen tiara and a sash that said "Miss Remembered."

Add Barry Bonds' upcoming trial on perjury charges, Marion Jones' crocodile tears and six months behind bars for lying to investigators, Tyler Hamilton's contention that a vanishing twin might have led to a positive blood-doping test and Floyd Landis' Jack Daniel's defense. Pretty soon, McGwire starts looking like a model of integrity.

Strange, isn't it, how steroids inflate muscles and statistics, yet shrink the definition of decency?

McGwire could vault the bar easily if he just explained himself. At the hearings, he seemed horribly conflicted and somewhat ashamed. He didn't like being questioned, but he also turned squeamish when he avoided answering. He can fix all of that. A month from now seems like the perfect time.

He may have reasons to wait longer, perhaps out of fear that the government will demand other people's names - suppliers, ex-teammates. If so, another February, when everyone else's statute of limitations has expired, would do. It probably won't be enough to put McGwire in the Hall of Fame, but it would win a lot of respect and a special place in baseball history. He'd be that rare batter who took a swing years late and still made contact.

E-mail Gwen Knapp at gknapp@sfchronicle.com.

This article appeared on page D - 1 of the San Francisco Chronicle