SOCHI, Russia (Reuters) - Lewis Hamilton dismissed talk of having one hand on his fifth Formula One championship on Thursday but warned rival Sebastian Vettel that he felt stronger than ever and in a better position than last year.

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The Mercedes driver, 40 points clear of Ferrari’s German with six races remaining, sounded relaxed as he faced reporters at the Russian Grand Prix.

“I don’t think you ever have one hand on it,” he smiled. “You either have both hands on it or you don’t.

“There’s still a long way to go and a lot of points available.”

The Briton said, however, that a lot of things, largely invisible to anyone outside the team, had made the difference compared to last season; improved relationships and communication, health and time management.

“Healthier, happier and stronger than ever,” Hamilton said of himself.

Mercedes have yet to be beaten in four Russian Grands Prix, with Hamilton winning two of them, but Vettel started on pole position last year in a race won by Valtteri Bottas.

Hamilton arrives this time on the back of four triumphs in five races. Another victory on Sunday would be his eighth of the campaign and leave him in a position to take the title without having to win again.

The Briton said if it had taken time to work up to his current level of performance, that was because he had started the season still exploring the car’s complexities and how to get more out of it than even the team imagined possible.

The Russian Grand Prix was held in April last year, with Hamilton finishing fourth, but the schedule change means Mercedes come to Sochi with the car and driver much more in tune.

“I really do believe this weekend we will be in a better position than we were last year,” said Hamilton.

“Our understanding is far greater of the tire than it was last year when we arrived here.

“It’s still a challenge to get right. We will take our understanding of last year with a pinch of salt because the car is different and we’ve got a different tire this weekend. We’ll be faced with different challenges, I would assume.”

Speaking separately to reporters, Vettel felt he could still close the gap.

“Last year it was a surprise to be so competitive here, this year we expect to be competitive,” said the German. “I think we need to not get distracted by the results but focus on the job we need to do.

“I think we have a fair chance. We have races in the past that we should have won and didn’t and others we won that we shouldn’t have. So you never know what’s going to happen.”