The Giro d'Italia was once known as a predominantly affair but a clear strategy to internationalize the race has paid off and this year a host of established, foreign grand tour stars will head to Belfast for the start of the Italian race. Nairo Quintana and Joaquim Rodriguez headline a very strong list of contenders that includes four past grand tour winners and even though the sad absence of Richie Porte will be felt, the organizers could hardly have wished a stronger line-up for the three-week race. CyclingQuotes.com takes a thorough look at this year's favourites and outsiders and finds out all about their strengths and weaknesses.

When Michele Acquarone took over the reins from Angelo Zomegnan as race director of the Giro d'Italia, he had a firm objective. He wanted to internationalize what was by many seen as a mostly Italian race in an attempt to challenge the position of the Tour de France as the world's leading bike race and the first premise for success in that regard was the attraction of more international stars to the race's line-up.

The effort has clearly paid off as a more balanced route design with shorter transfers, no excessive climbing and more time trialing has convinced several international stars to make the Giro their main target of the season. Already last year the reigning Tour de France champion took to the start and even though Chris Froome won't be at the start in Belfast on Friday, this year's line-up is spearheaded by the other two podium finishers from the 2013 edition of La Grande Boucle.

With defending champion Vincenzo Nibali focusing on the Tour de France, it may in fact be difficult for the home nation to even put a rider on the podium. Home riders like Michele Scarponi, Domenico Pozzovivo and Ivan Basso will have to beat the likes of Nairo Quintana, Joaquim Rodriguez, Cadel Evans, Daniel Martin, Rigoberto Uran and Rafal Majka to make it two Italian wins in  a row.

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.

Nairo Quintana (*****)

It takes a big talent to line up as the big favourite in a grand tour at just  24 years of age and in fact it hasn't happened since  Jan Ullrich took the start line of the 1997 Tour de France. Nonetheless, it is hard to look beyond Nairo Quintana as the man to beat in this year's Giro d'Italia - even though it will only be his first participation in a three-week race.

Ever since his victory in the 2010 Tour de l'Avenir, it has been evident that Quintana is a very rare talent but it has come as a surprise for many - even his own Movistar team - that he has matured into a winner candidate already at 24 years of age. However, his excellent performance at last year's Tour de France has convinced manager Eusebio Unzue and the rest of the cycling world that he is already ready to target the top step of the podium and the wily Spaniard has selected a team that is fully devoted to their young Colombian.

It has been a rapid rise through the ranks for Quintana who joined the WorldTour just two years ago when he signed with his current team. In his first year, he proved his talents when he won the Vuelta a Murcia in the early part of the season but he first made a name for himself at the highest level when he won the queen stage of the Criterium du Dauphiné. While the Sky machine was powering along at a brutal pace that prevented the likes of defending Tour champion Cadel Evans from attacking, Quintana took off on the Cold du Joux-Plane, and by using both his great climbing and descending skills, he held on to take a breakthrough solo victory.

He went on to win the Route du Sud a few weeks later and those performance raised the expectations for his debut at the Vuelta a Espana. Already that year he introduced his habit of preparing his three-week races with limited racing and intense training in Colombia but his first attempt was a clear miss. Entering the race, he wasn't firing on all cylinders but bounced back with an excellent domestique performance in the mountain stages in the final week where he emerged as the fourth best climber behind the superior trio of Alberto Contador, Joaquim Rodriguez and his captain Alejandro Valverde. He made use of his post-Vuelta condition to take his first big classics victory at the Giro dell'Emilia which created lofty expectations for his 2013 season.

A crash prevented him from excelling at Paris-Nice but he got his deserved place  in the spotlight when he beat riders like Rodriguez, Valverde and Bradley Wiggins in the first big mountain stage of the Volta a Catalunya. A time loss on a descent on the first day meant that he could only manage fourth in that race but his excellent condition prompted the Movistar management to change his schedule and line up their upcoming star at the Vuelta al Pais Vasco.

That race proved to be the major breakthrough for the tiny Colombian as he ended up taking the overall victory. Not only did he climb at his usual high level in that race, he secured the win by doing an excellent time trial on the final day. That performance made him a dark horse for the Tour de France and the excitement was made even bigger by the fact that he arrived at the race straight from Colombia, with no one knowing anything about his condition.

Even though he was widely tipped as an outsider, few would have expected him to perform as he did during those three weeks in France. Entering the race as a luxury domestique for Valverde, he was used to animate the race and test Chris Froome in the Pyrenees but when Valverde had his horrible day on the windy roads to Saint-Armand-Montrond, he took over the captaincy role at just 23 years of age.

Quintana coped with the pressure and ended the race in second overall after winning the final big mountain stage, even taking the mountains jersey in the process. In the final week, he was even stronger than Froome on the climbs and if he had been racing more conservatively in the Pyrenees, he would have been a lot closer to the win. Even if he had started the race as team captain and had races as such, however, he would never have been able to beat the superior Brit who was far stronger than the Colombian until the final week and had a clear advantage in the time trials.

With Quintana having lots of room for improvement, cycling fans were looking forward to his return to La Grande Boucle and a much closer battle between the two grand tour stars. However, his team made the - probably wise - decision to allow him to mature under less pressure at the Giro than going straight after the win in the sport's pinnacle event. The decision was clearly against Quintana's own desire to return but a couple of factors contributed to the decision. First and foremost, Unzue is convinced that it will be easier for his young star to handle the pressure of being a race leader for the first time in a race with less media attention. Secondly, he wanted to give Alejandro Valverde one final chance to reach his life-long dream of stepping onto the Tour de France podium.

However, the decision clearly wasn't an easy one for the team to make. The official announcement wasn't made before late January as sponsor Telefonica were clearly keen on seeing Quintana return to the Tour. Despite his reluctance, the Colombian has accepted his schedule and has carefully prepared the Giro in his trademark way by returning to Colombia without doing any racing since he ended the Volta a Catalunya in a fine but unspectacular fifth.

Quintana has been riding solidly in the first of the season but he has not yet hit the condition that allowed him to shine last July. He was excellent already in January when he won the Tour de San Luis but admitted that he was too far ahead at that early point of the season and deliberately slowed down a bit in his training. The effect was evident when he returned to Europe and even though he finished 2nd in Tirreno-Adriatico and 5th in Catalunya, those performances didn't suggest that he will win the Giro.

However, Quintana's performance in last year's Tour de France suggests that he is the strongest climber in the race if he hits his peak condition. In a race that will mainly be decided on the ascents, climbing skills are the single most important attribute for a rider with winning ambitions and in that area Quintana is unrivalled. He will find the mountainous course with its 9 summit finishes to his liking and it won't be a problem for him that they have a rather diverse nature. Long climbs, short climbs, steep climbs, gradual climbs: Quintana has the ability to handle any kind of ascent. Furthermore, he excels at high altitudes and the riders will hit some pretty high peaks in the Dolomites in the final week.

In last year's Tour de France, Quintana and Rodriguez were climbing almost at an equal level but a number of factors elevate Quintana to the number one favourite. First and foremost, Rodriguez has always struggled a bit on long, regular climbs and the Giro offers three key summit finishes that could put the Katusha captain into difficulty. The Montecampione, Panarotta and Zoncolan finishes are all more about regularity than explosiveness and this suits Quintana a lot more. In those stages, Quintana will be able to do some major damage and he is not afraid of attacking from afar. At the same time, he is also rather explosive and shouldn't be too far off the mark in the more irregular finishes as well.

While he is no time trial specialist, Quintana performs well in the individual discipline and as he proved in the Basque Country last year, he really excels on hilly courses. In the past he has only struggled in the really flat courses but his performances this year indicate that he has improved his time trialing a lot over the winter. He won't find any really flat TTs in this year's Giro. The rolling course in the Barossa valley should suit him well and the mountain time trial to Monte Grappa is perfectly suited to a pure climber like him. In fact, he will be the man to beat in that kind of test as he has performed excellently in past mountain time trials. Finally, he is supported by a fabulously strong team that includes climbers Igor Anton, Jose Herrada, Eros Capecchi, Andrey Amador and Gorka Izagirre and with Adriano Malori and Jonathan Castroviejo combining forces with Amador in the team time trial, he will even be able to take time already on the opening day.

If everything goes to plan, it is hard to see any chink in the Quintana armoury. The only cause for concern is his rather unique way of preparing his biggest races. It worked excellently for last year's Tour de France but in fact it has only done so in one of three occasions. He failed to reach his best condition for the 2012 Vuelta and for last year's Worlds and there is no guarantee that he will enter this year's race firing on all cylinders. He had planned to ride the Vuelta a Asturias as his final preparation but a last-minute cancellation leaves him with no racing in his legs when he rolls down the start ramp with his team in Belfast. With the first major test coming on stage 8, he will have time to get into racing mode but his lack of racing raises a few questions about his form.

His team is trying to play down expectations by making a podium spot the official target but there is no doubt that Quintana himself is gunning for the victory. Last year he proved that he can handle the pressure of being a major actor in a major bike race and he appears to be mentally strong. Combining that psychological aspect with his undisputed position as the best climber in the peloton makes him the point of reference in this year's Giro d'Italia and if everything goes according to plan for Quintana, he could become the second Colombian to win a grand tour and the youngest rider to win a three-week race since Damiano Cunego won the 2004 Giro.