cineteq said:
How sprinting is a key skill for a GC rider? Has Contador been prevented from winning a GT because he can't sprint? He might not be a all-rounder in your book, but he has the two key skills that matter the most.
PS: Has Cancellara been prevented from winning a monument because he can't climb? Yes.
Has Contador been prevented from winning a monument because he can't ride on cobbles or sprint? Yes.
Sprinting may not be a key skill for a GC rider, but it IS a key skill for being considered an all rounder.
Those two key skills only matter the most if you're talking specifically about stage racing. But stage races (and especially GTs, which only number 3) do not account for the entire racing calendar, and Contador's inability to sprint or ride on cobbles has lost him many a one-day race that other riders, who cannot win a GT but nevertheless have all the requisite skills to be considered all-rounders, can win.
Realistically, your original criteria, that an all-rounder must be able to win GTs as well as Classics, is far too limiting, because it unfairly weights skills as so few riders are able to contend for GTs. An all-rounder is so called because he has all skills. If you used shorter but difficult or prestigious stage races, then it would be less clearly biased. That Contador, a man entirely lacking in some skills and that hasn't even attempted a whole subsection of races, can be one of your top picks for best all-rounder, shows that the criteria for all-rounder that you set needs some tweaking. Sylvain Chavanel can compete at the Ronde and to a slightly lesser extent at Roubaix, in hilly Classics, has podiumed Paris-Nice, won very lumpy Grand Tour stages, can time trial, is a more than decent descender (see Paris-Nice '09, when he catches Schleck & Voigt then carries them to Contador, Sánchez & Colóm)... yet he can't be considered an all-rounder and Alberto Contador can?