TOKYO, Oct 4 (Reuters) - Lewis Hamilton does not believe he is taking a gamble by leaving McLaren for Mercedes next season, saying the move could catapult him into Formula One's pantheon of greats even if it does not pay out immediately.
"No doubt it was one of the most difficult decisions I've faced in my life up to now," the 27-year-old told Reuters in an interview in Tokyo before this weekend's Japanese Grand Prix at Suzuka.
"But a lot of other racing drivers, a lot of greats - (Alain) Prost and (Ayrton) Senna, they've all been with several teams," added Britain's 2008 world champion.
Hamilton's decision to cut the umbilical cord with McLaren ended season-long speculation about his future and could usher seven-times world champion Michael Schumacher back into retirement as the man he replaces.
"I'd been thinking for quite some time... what I wanted to do with my future, where I want to go," said Hamilton, who has raced for McLaren since his sensational F1 debut in 2007.
"It's easy staying in the same place, but going somewhere else and taking on a new challenge is sometimes maybe even more exciting."
McLaren team principal Martin Whitmarsh called the move a "mistake" but Hamilton said he knew what he was doing.
"I don't (think it's a gamble)," he said. "Not really. I've had such a great career with McLaren. I signed for McLaren when I was 13 and have had such an incredible journey with them.
"In the end I had two offers on the table which were very similar but one was a lot more exciting. It's just a challenge.
"I could stay in the great car that I have, which I've worked really hard to help develop with the team, or go to a car that's not so well developed and help it."
Hamilton said he had not spoken to McLaren's executive chairman and former team principal Ron Dennis after making his decision to leave last Wednesday, two days before the announcement.
"We didn't speak about it," said Hamilton, currently fourth in the world title standings, two spots higher than McLaren team mate Jenson Button. Ferrari's Fernando Alonso is out in front.
"He (Dennis) spoke to me in Singapore (the race before Japan). That was about it. We haven't spoken since."
Mercedes team chief Ross Brawn has tipped Hamilton to be able to emulate Schumacher by dominating Formula One at his new team, just as the German did with Ferrari in the early years of the century when Brawn was the technical director there.
"Of course that's always the plan," said Hamilton, his diamond earring glittering. "But things don't always go to plan."
Most observers expect Mercedes to become a real force in 2014 when the sport is due to switch to new 1.6 litre V6 turbo engines.
Mercedes have won just once in 50 races since they returned to the sport as a full works team in 2010 and Hamilton recognised he might not be able to fight for the 2013 title.
"No, I'm fully aware the car at the moment is not a world championship-winning car," he said. "The car that I'm in right now is a car that I've developed. Next year will be an evolution of the car that I've helped develop and that will be a championship contender.
"But we (Mercedes) will work very, very hard to have a better year next year, but it takes time. You don't just arrive and things change," he added with a click of his fingers.
"I think the focus is more long-term," he stressed, having bought into Brawn's track record of producing winning cars after a period of building and tweaking.
Brawn GP, previously under-performing Honda, won both titles in 2009 with Hamilton's current team mate Jenson Button.
Mercedes bought Brawn GP at the end of 2009 and renamed it.
"If I can go there, help them progress, if we get some wins, if we eventually win the world championship - that's going to be an incredible feeling for all of us," said Hamilton.
The Briton insisted there were no hard feelings, likening his exit from McLaren to leaving home.
"Yeah, definitely, because it's my family," said Hamilton. McLaren will always have that place in my heart because I signed when I was 13, met Ron when I was 10. I'm so incredibly grateful to Ron.
"But we must not forget that, whilst it was Ron who signed me up, at the time it was McLaren and Mercedes, and Mercedes had to also say, 'Yes, we'll take him' so it was a joint decision by them.
"My last five years has been Mercedes and McLaren so I've always been a part of the Mercedes family but now I'm moving to be a full part of the family." (Reporting by Alastair Himmer; Editing by Alison Wildey)