Since when does extraneous factors take preference over comparable data? We certainly can't compare riders by how much wind they face going up a mountain. How does that work exactly? It is not rocket science these calculations. Weight, grade, ascent and stopwatch ... that is it. The extraneous factors you mention can be off in BOTH directions, not just revisions downward from suspect performance levels. When Contador went up Verbier all we heard about was tailwinds and drafts, as if they were the main cause of the greatest performance ever on a mountain in any Tour de France. Tailwind or not, draft or not, it was either ~1850 VAM or over 1900, but in either case the performance indicated doping. No positive and no evidence other than the data calculated from the performance. What did we hear after Ventoux? Tailwinds again and how they could reduce the levels of a suspect performance. Put plainly, when the data is added up, some don't particularly like what said data adds up to.