Bonds is an admitted cheater, testifying under oath in a grand jury that he used the substances, but claimed not to know what they were.
"I judge players by their eras and who they played against," he said Tuesday. "Clemens and Bonds, they were the best pitcher, player of their eras. And while I wrestled with it, I just decided that how do I know who did and who didn't? ... I finally just decided, you know what, they're so great that they should be in the Hall of Fame because it's a museum of baseball history."