The centenary edition of the Tour de France starts in Corsica Saturday, and it promises to be one of the most competitive races in years. Whereas last year’s course and competition played to the methodical strengths of eventual winner Bradley Wiggins and his Team Sky machine, the 2013 edition should prove more volatile. The fields is stacked with explosive climbers compared to last year’s crop of steadier big-engine type of riders, so there’s potential for a shake-up on nearly every one of the 11 hilly or mountainous stages. And given that the race concludes with a climbing ITT followed by three brutal mountain stages in the Alps, the overall may very well be up in the air until the final processional onto the Champs Élysées. Here are our picks.