BARCELONA, Spain - Lewis Hamilton handed Formula 1 a compelling storyline for the new season from the moment he decided to leave the comfort of McLaren for a the challenge of Mercedes.Time will tell whether the 2008 World champion has taken a wrong turn but, apart from careering into a tyre wall on his first day of testing, the early signs look promising.POSITIVE ATTITUDESome are convinced the Briton will not be a title contender in 2013 and might not even win a race; others are having second thoughts ahead of next weekend's season-opener in Australia (March 15-17) The man himself is sure he's on the right track and could be on to a winner."It's not 'no chance' and not definitely 'we will'," Hamilton said of his title prospects after he wrapped up testing with a time a second quicker than the race lap record at Barcelona's Circuit de Catalunya (though it was beaten the next day by Merc team mate Nico Rosberg)."We will definitely win a race at some point," added the 28-year-old Briton, whose 21 GP wins have all been for McLaren - the team that backed him as a boy and gave him his F1 debut in a stunning 2007 season.The debate over whether he was wise to turn his back on regular winners and title contenders for less competitive rivals is sure to rumble on for months, particularly if the new McLaren makes a strong start and the Mercedes eats tyres like it did last year.FIRST RACE WILL TELLHamilton has said that the main target is to be competitive in 2014, when the regulations change significantly, and anything before that comes as a bonus. How much he really believes that, and how much patience he has, are moot points but the pressure will be much more on the team to deliver than on a driver whose talent is beyond doubt."There is everything to play for still," Hamilton said. "We won't know until the first race but don't be surprised if we get to the first race and we are not at the front. We are going in the right direction though," Test-session times can be misleadin and Mercedes flattered to deceive last year, with one-lap speed not necessarily translating into performance over a race distance. There is a suspicion rivals have kept their powder dry but there is no question that the new Mercedes F1 W04, after initial teething problems, is an improvement on last year's model.SCHUMACHER DISAPPOINTMENTMercedes has had three disappointing seasons since it bought the championship-winning Brawn GP team at the end of 2009 and renamed it as the works outfit. Germany's Nico Rosberg won in China in 2012 - the team's sole success to date - but it proved a flash in the pan with compatriot and seven-times World champion Michael Schumacher retiring with just one podium for Mercedes in his three "comeback" years.The team ended the season in Brazil with a car well behind the leaders but with the morale boost that comes from having signed one of the quickest and most exciting drivers on the grid. Some said the move was all about money and the jet plane Hamilton has acquired shows there is plenty of that around, as well as the freedom to build his own 'brand'.But his behaviour since he arrived at Mercedes, despite management upheaval, has indicated that he is in a happy place both on and off the track. The Englishman has, in metaphorical terms, grown up and left home. Like Jenson Button when he moved to McLaren from Brawn in 2009, he has a new challenge and doubters to prove wrong.LEAVING THE NESTHamilton's gamble, if it is one, is nothing like the decision made by Canada's 1997 champion Jacques Villeneuve when he switched from multiple title-winners Williams to newcomers BAR in 1999.Mercedes, a much more recognisable brand than McLaren beyond the confines of F1, has the resources and expertise to deliver. It may also have a big advantage in 2014 when the V6 turbo engine rule introduced. "I don't feel any expectation. If anything I feel like I've got a free ticket," Hamilton told reporters. "It's a year where we know that we may not have the best package but it's a challenge for me."That's for me to enjoy. It's not pressure from outside. The pressure is all on the other guys who have great cars which have evolved into the 2013 car. The pressure is on them to compete and perform. We only have everything to gain."STRONGEST OPPONENTFerrari's Fernando Alonso, Hamilton's former McLaren team mate and a double World champion, would be the last to write-off the Briton's chances. "Who is the strongest opponent, the strongest driver on the grid? Who is the one you have to keep an eye on? It is Hamilton - and it will still be Hamilton in 2014," the Spaniard tolsaid in January."I am sure he will be able to win. He is a super-good driver because he won every year with any car. He won in 2007 and 2008. In 2009 they started around two seconds off the pace with McLaren and Hamilton was able to win races. And it was the same in 2010."Alonso, who spent one difficult year at McLaren in 2007, had no doubt when Hamilton announced his departure in 2012 that the Briton had made the right decision. He cited his own example and that of four-times champion Alain Prost as evidence of how beneficial a change could be.HAPPY CHAPPYHamilton would agree with that. "I'm happy I've got a new challenge, happy I've got a new start, happy it's a fresh chapter in my life," he said at the first pre-season test in February."Happy and excited because I know I can contribute and with a lot of hard work and perseverance I think we can get there."