Button 'more relaxed' ahead of Brazil

The Brawn GP driver thinks the fact that rivals Sebastian Vettel and Rubens Barrichello must outscore him in Sunday's race to keep the title fight alive has left him more relaxed than he has been for ages.

"It does feel different," said Button about how his feelings this weekend compare to Japan a fortnight ago.

"I feel a lot more relaxed here compared to Japan and maybe the last few races. It is a very different situation. They have to do me by four points at least - and Sebastian has to beat me by six. That is if I want to win the championship here.

"It is a good situation to be in. This is a circuit I enjoy. I know Rubens is always fast here, but I have had some very good results here in the past as well.

"The only thing is the unknown really - which is the Red Bull. We don't know how quick it will be around this type of circuit. I feel very happy, I am really excited about the weekend. We don't know what the weather is going to do, it looks wet/dry/wet/dry all through the weekend. It is about keeping it simple and not making it too complicated."

Although a podium finish on Sunday would be enough to guarantee Button the championship, he has said he is not going to think too much about the mathematics of what he needs to do until after the chequered flag.

"I have tried not to [think about the maths]," said Button. "My engineer told me a few days ago when I was on holiday - and I told him 'Shov, we will just go there and do whatever we can and see where we end up'. I will do it only on the slowing down lap."

He added: "It is an easy situation to be in. If you know you have to go out and win a race, it is a much more difficult situation than knowing you have to score four points.

"I am not coming here thinking how many points I need to get and how many points I can finish behind my two rivals. It is about me relaxing and enjoying the race and not doing anything too stupid.

"It is about those two being aggressive and trying to get as many points as they can, which is the way it has be for them. They have to get more points than me, it is an important race for them."