Bjarne Riis was full of doping when he won his one Tour, to be sure, but I haven't seen much evidence that his "conversion" isn't genuine - he's had to work hard to regain himself the benefit of the doubt, of course. He's been linked to some people who were accused of doping, yeah, but as you say, that doesn't prove much.

How realistic is that assumption, really? I mean, if you assume that a high-profile rider like Contador is doping for most of his career, considering the amount of tests he's had to take during all that time, that would essentially mean your tests are, well, the next thing to worthless, catching doping only when the riders get careless. But the tests seem pretty efficient otherwise, so are we really supposed to think Contador just is that much smarter or has access to stuff that is that superior?

In nearly all of the high-profile doping cases in recent years, the result didn't come as much of a surprise when you looked at the rider's recent achievements. Landis - his ride to Morzine was a throwback to the good old days, but when a guy who was never much more than a (pretty good) domestique suddenly pulls Merckxian stunts in an era when those are generally considered impossible, yes, well. Schumacher - suddenly beating Cancellara twice in TTs in a single Tour when he rarely came close before. Heras - being surprisingly good througout a whole Vuelta and then actually winning the final time trial. Piepoli and Ricco - being able to attack time and again, even on the steepest mountains.

Contador - or Fränk Schleck, for that matter - doesn't fit that pattern. It's not impossible, I suppose, that they'd fall into the category of riders who resort to doping when their form isn't good enough and they are desperate to live up to expectations, although I'm still not convinced either one was guilty of even that much. But their careers are credible, show realistic progression, and no impossible feats inconsistent with what they've ever shown before.

Armstrong is of course the big riddle in that view of doping... his pre-cancer career, while certainly of considerable merit, didn't really show any Tour-winning ability. But he's come out of that cancer with an indomitable willpower, and perhaps that did make the difference between a sub-top rider and a real world class one, without any need for doping. Or perhaps not.