Quik has it right. I would slightly modify his statement to "a lot of competitors" instead of "everybody" but everything else is what I believe. That was what Balco was all about. Coming up with new methods to mask doping and passing tests (different drugs, schedules, etc.). This easily explains how cheaters pass so many tests but then finally get caught.
As a final note, I just saw Landis' press conference statement for the first time. How poor was that? He starts out "I have never been involved in," then has to pause and look down at his written statement, then looks back up and says "doping process." I mean the guy can't even keep straight what he's supposed to say. If you're clean, you should have no problem coming out and saying it without a prepared statement. Something like, "I have never taken steroids, period."
