"Chris Froome is relaxed and focused – you see it in the way he races. Alberto is always worried about making the most of opponents' weaknesses, where Froome is more confident in his own capabilities and just tries to ride off," Roche explained.
"Froome thinks more about his own ride rather than planning through attacking. You've seen it many times – riders attack and Froome keeps his tempo. Alberto sees his opponents having trouble on a wet descent and he puts the hammer down."
The Irishman lined up with Contador in the 2013 and 2014 editions of the Tour de France, but this year he is part of Sky's nine-man Tour roster.
Several other riders and staff have switched between teams Tinkoff and Sky. Froome's main helper, Richie Porte, assisted Contador to grand tour wins and Michael Rogers, now with Tinkoff, helped Bradley Wiggins win the 2013 Tour.
Contador's tactical genius has helped him win races when the odds were against him. In 2012, after coming back from a doping suspension, he turned the tables on Joaquím Rodríguez in a long attack and took control of the Vuelta a España for an eventual win.
If Froome is unable to shake Contador and feels at risk as the race makes its way towards Paris, he could draw on Roche's experience to beat Contador.
"I can't compare Chris to when he won the Tour in 2013 – I wasn't there – but he is in good shape and really confident," said Roche.
"Chris is going to attack and he believes that he can attack and drop him. That's why the team is balanced with riders like Richie who know how to put on the pressure. Froome then can do it on his own on the climbs."
Froome himself says he is confident he can win a second Tour.
"I've no doubt Alberto is in amazing shape after winning the Giro d'Italia," he said. "He set himself the big task of the double: that's a big challenge for him and it's going to be interesting to see how he pulls up in the third week given he's already got a Grand Tour in his legs this season.
"I've been here, I've done this now a few times. I'm getting into the routine. It doesn't feel like such a burden having pressure any more. Certainly not coming in as defending champion I've got everything to race for this year.
“Everyone's just looking forward to getting it started now.”
A crash cut Froome's title defence ride short in 2014. He said that from the moment he left in stage five, he began thinking about returning to win in 2015.
He did all he needed to do to be ready, including winning early season stage races, the Ruta del Sol and the Critérium du Dauphiné. Now, with the help of some of Contador's former guard, he will take aim at cycling's current grand tour king and another Tour title.
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