The Vuelta a Espana may have a reputation as a revenge race for riders who missed out in the Tour de France but there won't be much redemption in the air ar this year's Spanish grand tour. Instead, the race has attracted a formidable line-up of grand tour stars who travel to Spain on the back of what has mostly been highly successful seasons. Giro champion Vincenzo Nibali (Astana) and local heroes Joaquim Rodriguez (Katusha) and Alejandro Valverde (Movistar) have attracted most pre-race interest but they will have to contend with exciting talents Sergio Henao (Sky), Carlos Betancur (Ag2r), Rigoberto Uran (Sky), Thibaut Pinot (FDJ) and Rafal Majka (Saxo-Tinkoff) and accomplished grand tour veterans Michele Scarponi (Lampre), Ivan Basso (Cannondale) and Samuel Sanchez (Euskaltel). Defending champion Alberto Contador and the best two riders from the Tour de France may be absent but apart from that Vuelta organizers Unipublic could hardly have imagined a stronger line-up for their race. CyclingQuotes.com takes a thorough look at this year's favourites and outsiders and finds out all about their strengths and weaknesses.

Last year's Vuelta a Espana evolved into a local battle between the three Spanish grand tour giants Alberto Contador, Joaquim Rodriguez and Alejandro Valverde but this year's race should have a much more international flavour. Valverde and Rodriguez are back after having impressed in the Tour de France but those two join Samuel Sanchez on the list as the only genuine Spanish winner candidates.

Italy's three grand tour winners Vincenzo Nibali, Ivan Basso and Michele Scarponi have all made the Vuelta a prime target and a host of exciting Colombian talents are ready to continue their recent domination. On a course that offers no less than 11 uphill finishes, such a bunch of climbers can only create a very exciting bike race and the race could very well shape up to be the closest of this year's grand tours.

CyclingQuotes.com has taken an in-depth look at the race's favourites, assigning 5 stars to the race's biggest favourite, 4 to his two biggest rivals, 3 to three other potential winners, 2 to four of the podium contenders and 1 to 5 of the race's minor outsiders. In this article, we take a look at the big 5-star favourite while the assessment of the other winner candidates follow in later articles.

Vincenzo Nibali (*****)

Among the current professionals, only three riders are multiple grand tour winners. Alberto Contador has of course  been the outstanding grand tour rider of his generation while Ivan Basso has taken two Giro victories during a long and turbulent career. Those two are joined on the list by Basso's former protégé Vincenzo Nibali who has steadily evolved into Italy's leading rider for the three-week races and one of the very best in this difficult discipline.

That steady progression has taken him from his status as a talented youngster whose fruitless suicide attacks often forced spectators to clutch their heads, to the point where he can now enter his first grand tour as the major favourite. He first showed the kind of consistency that is needed to win a grand tour during the 2009 Tour de France and went on to finish 3rd while working for Basso in the Giro less than one year later.

His major breakthrough was, however, his 2010 Vuelta win. In a race plagued by inconsistent performances, Nibali had fewer bad days than his rivals and became a surprise winner of the Spanish grand tour. He battled a superior Alberto Contador in the 2011 Giro and had his only major failure in that year's Vuelta. Last year he made it onto the grand tour podium that had so far eluded him when he finished 3rd in the Tour, albeit without ever being a real winner candidate.

What has taken him the next step from podium contender to race favourite was his crushing dominance in this year's Giro. Having always had that odd bad day that has cost him too much time, Nibali finally got through an entire three-week race without showing any sign of weakness at all. Gauging his effort perfectly, he raced a controlled race until the final tough part where he unleashed all his power to win the mountain time trial and take a dominant win in the snow on the torturously steep Tre Cime Di Lavaredo climb.

You can't build a trend on just one stand-out performance but it is a fact that the number of his bad days has gradually been reduced and those odd crises have been less costly. It's no coincidence that he has won the Tirreno-Adriatico twice in a row and has added two Giri del Trentino to his palmares. Whenever he enters a stage race with any kind of winning ambitions, he is a genuine contender, and he is surely the man to beat in this year's Vuelta.

This year's course is extremely mountainous with no less than 11 uphill finishes and some extremely steep finishing climbs. As Nibali is no pure climber, that may be seen as a disadvantage compared to riders like Joaquim Rodriguez, Sergio Henao and Alejandro Valverde but don't be fooled by Nibali's big gear and his apparent lack of explosiveness. He may never be capable of sprinting up a steep ramp against the likes of Rodriguez and Valverde but his stinging attacks in the classics and the mere fact that he has won the Giro with its many irregular, steep climbs prove that he is well-suited to the kind of racing the Vuelta offers. It's no coincidence that he has come close to wins in both Il Lombardia and Liege-Bastogne-Liege and finished 2nd on the excessively steep ramp in Valdepenas de Jaen that will be back on the route for this year's Vuelta. When he won this year's Tirreno, it was based on his dominance on the short, extremely steep climbs on the epic penultimate stage. Earlier in his career, he struggled on long, steep climbs - which would be a weakness in a race that includes the Angliru - but his splendid ride on Tre Cime Di Lavaredo in this year's Giro and on Monte Zoncolan 2 years ago prove that he has overcome those difficulties.

Nibali has never been a time trial specialist and he will never be one. However, Specialized and his Astana team have invested plenty of time in the further development of his abilities in that discipline. His results during the early part of the season - most notably in the long Giro time trial in which he finished 4th - prove that those efforts haven't been in vain, and it will make the race's only time trial an asset for Nibali compared to his main rivals. If one adds the fact that he is surrounded by what shapes up as the strongest team in the race - with Janez Brajkovic, Jakob Fuglsang, Paolo Tiralongo and Tanel Kangert forming a fearsome quartet of mountain domestiques and Andriy Grivko adding further horsepower for the team time trial - he has all the capabilities to win on this year's course.

Nibali only has two weaknesses that his rivals may try to exploit. In a race with bonus seconds and numerous short ramps at the finish, sprinting becomes important. Nibali has no chance against the likes of Rodriguez, Valverde and Henao in an uphill sprint and with 20 seconds on offer, that could be costly for the Italian. Secondly, the number of uphill finishes may pose a problem. Nibali's bad days may not have completely vanished but just been sufficiently reduced to be less noticeable. Nobody ever finds out whether a GC rider has a bad day on a flat sprint stage but in a race in which most stages can end up as a costly affair, crises may be more difficult to hide.

When Nibali stands out as the favourite despite those weaknesses, it is mainly due to his freshness. On this course, he may have had difficulty battling Rodriguez, had they both been on equal terms. When they aren't, it is due to their different race schedules. Rodriguez raced the Tour de France and even though he hasn't raced in between his grand tours, he may pay the price in the end. No one has won the Vuelta on the back of a top performance in the Tour de France for more than a decade and if anyone tries to deny the importance of this fact, they'd better ask Chris Froome how it feels to race the Tour-Vuelta double at a high level. Nibali will be much fresher at the start and his 2010 season shows that he is fully capable of performing well in both the Giro and the Vuelta.

At first he suggested that the world championships was his main autumn target but he has now made it clear that he enters the Vuelta with clear winning ambitions. Everything suggests that he has timed his condition to perfection. He made his usual modest performance in the Tour de Pologne but his impressive showing on the queen stage in the Vuelta a Burgos proves that he is ready. He may not have been as dominant as he was during the Giro del Trentino and his Giro preparation but at the end of a season that may not be a bad sign. He will only have improved massively since and so he will be very hard to beat as he aspires to be the first rider since Alberto Contador to make the Giro-Vuelta double.