Stage wins: Four (2012 - stage seven; 2013 - stages eight, 15 and 17).
This season Froome has not been the near-unbeatable beast he was in 2013 and is nervous about the cobbled fifth stage. He won the opening two stages of the Criterium du Dauphine, but a crash contributed to his demise later in the race as he finished 12th, giving his rivals a boost ahead of the Tour. On the plus side, Froome appears to like the balance of his (Wiggins-free) team this year.
Stage wins: Three (2007 - stage 14; 2009 - stages 15 and 18)
The double winner, stripped of the third title he won in 2010 and his fifth place in 2011 for a doping offence, is showing glimpses of his best form and appears to be confident of another title. Whether it will be enough to distance Froome remains to be seen, but he's certainly the Sky man's biggest threat and many people's favourite to win yellow in 2014.
The formidable winner of the 2013 Giro d'Italia didn't ride in last year's Tour despite being Bradley Wiggins and Froome's nearest challenger in 2012. The Italian is a daring descender who could attack at any moment, but does he have a good enough team to beat both Froome and Contador? It's doubtful.
Valverde, another who has served a doping suspension, is Movistar's team leader and a rider who has proved his Grand Tour credentials before when he won La Vuelta a Espana in 2009. He may well team up with compatriot Contador in the mountains in an effort to weaken Froome and Sky.