Button happy to play role of smiling assassin

Sometimes you can tell a lot about a driver's demeanour when he is really under pressure. In Jenson Button's case, as he could become Britain's 10th world champion here in Interlagos this weekend, there are two tell-tales. He smiles a lot, and he plays things down. It's a habitual trait.

Actually, Button has been smiling most of the year, ever since six victories in the first seven races made the title seem like a slam dunk for the man who had been all but written off after seasons from hell with uncompetitive Honda machinery. Back then, he seemed so invincible that everyone else was racing for second place. Even when Sebastian Vettel and Mark Webber in their Red Bulls beat him in the rain in China in the third race, he got straight back on track in Bahrain and Spain, and grabbed the lead from the upstart German on the opening lap in Turkey just to put him in his place.

Things began to go wrong after that, as Red Bull hit a purple patch and Rubens Barrichello started to get a better handle on setting up the tricky Brawn he shares as Button's team-mate. Since that Turkish Grand Prix, Button has rarely looked a winner, while Barrichello and Vettel have each won twice.

Now it has come down to a two-race scrap, though six points – third place – here for Button could settle the issue on Sunday, a fortnight before the inaugural race in Abu Dhabi. Button has the odds in his favour with 85 points to Barrichello's 71 and Vettel's 69.

Small wonder, perhaps, that he was still smiling in the paddock here yesterday, after entertaining the British media to dinner at the Fogo de Chao churrascaria restaurant in downtown Sao Paulo the previous evening. This is a man who smiles habitually, a sunny-natured guy always slow to anger. He's been doing what he has wanted to do – racing – for most of his life, and since the age of 15 he has been paid handsomely to do so. So you wouldn't expect him to be anything else, in a life in which so many ambitions have been fulfiled. But he has never been under so much pressure to succeed, not least because of that points advantage and the fact he has led the series from the get-go.

If he should stumble at this late stage, as fellow countryman Lewis Hamilton did so dramatically here in 2007 when his own 17-point cushion was eroded by Ferrari's Kimi Raikkonen in the last two races, Button will forever have to live with the ignominy of being branded just another British hopeful who wasn't quite good enough. After the start he had to the season, few believe he could ever have such a fabulous opportunity again.

Yet despite that pressure, he was quietly confident as he played mine host. "I feel good, not least because a Virgin bash has been organised next Tuesday evening in London, just in case. The last time I had to rush away from a really important race result was when I had to fly to Tokyo for Honda in August 2006..." Immediately after he won his first grand prix, in Hungary.

So Button, coming up for 30 in January, continues to smile, and to play down the expectations of people who would dearly love him just to say the unthinkable: "Sure, I'm gonna wrap it up this weekend, no problem."

It's never been his style to push himself forward, to make such boasts, so instead he does the play-down routine. Defuses the expectations. It seems to have worked for him thus far.

Vettel, meanwhile, is free to do what he wants, which is to push for the victories and to hell with the consequences because his, at best, is an outside shot. And the German is clever, saying repeatedly that all the pressure is on the Brawn drivers. But Button argues that all three of them are feeling the same pressure because of the situation they're in.

"Sebastian saying the pressure is on us is not quite the case, it's the same for all of us," he pointed out. "We're all fighting for the championship, it's the first time for me, Sebastian and maybe Rubens. It's an exciting situation to be in, but I'm the one with the lead.

"We're all fighting for something that is far greater than we have achieved in the past. I don't think it adds to the pressure knowing that you could win the world championship, but it adds to the excitement for sure. I am positive."

Vettel's Red Bull has been modified further for this race, but Button says Brawn also have some tweaks up their sleeve. "We have a few changes that should help us around a circuit like this. It should be a good step forward. The last race [in Japan] was obviously difficult because of the starting position and the mistake on Saturday with the yellow flags. But the pace in races has been good lately, but it is always difficult when you start far back. It's so difficult to overtake these days in F1, but every opportunity I have had to make a move I've made."

Crucially, he did just that to new Renault signing Robert Kubica in Japan, and went on to score a point that he would not otherwise have garnered. Talk of it reminded him of a pebble in his driving boot: the accusation that he has just been driving for points in recent races, living off his points advantage.

"I haven't purposely gone out to finish in the points and not win," he said. "I go out to try and win every race I compete in and I have led the championship all the way through the season. It's a different situation for the people who are chasing. They need to be more aggressive than I am, for sure. I don't just want to finish in the points, that has never been my objective, but there are situations you don't want to put yourself into. I think I've had a reasonably good balance."

Barring disaster, Brawn will wrap up the world championship for constructors this weekend so long as one of their drivers finishes at least eighth, for all they need after a dream season is half a point over Red Bull to throw things beyond their reach.

"It's an amazing story and it is a Hollywood movie, if it happens," Button said of that side of the tale. "It's not certain yet. I think the team have been through a lot. It was a difficult situation over the winter, a lot of them found it tough, but in the end we got the deal done and were able to come racing. If we come away with the constructors' in the first season of Brawn GP, it will be a very emotional moment for everyone, as it was in Australia when we finished 1-2. It was the first time I've seen Ross [Brawn] speechless and if it happens here or Abu Dhabi it will be the same."

Again, there was that boyish smile, the one that has made rivals underrate Jenson Button throughout his career. But what if he were to lose "his" title to Barrichello?

Button laughed nervously, and said only part in jest, "If Rubens won the championship, I would absolutely hate him. I'd also respect that he did a better job over the 17 races."

That would be when the smiling finally stopped.

Final countdown: Jenson's requirements

*What Button needs to do

*Finish ahead of Barrichello (RB) and Vettel (SV), or come in first three.

*Finish in fourth or fifth and hope RB fails to win, or finish sixth or seventh with RB not in first two and SV not winning, or finish eighth and RB not in first three and SV not in first two, or, if he fails to score, hope RB not in first four and SV not in first two. Simple.

*Previous British Champions

1958: Mike Hawthorn (Ferrari)

1962, 68: Graham Hill (BRM/Lotus)

1963, 65: Jim Clark (Lotus)

1964: John Surtees (Ferrari)

1969, 71, 73: J Stewart (Tyrrell/Matra)

1976: James Hunt (McLaren)

1992: Nigel Mansell (Williams)

1996: Damon Hill (Williams)

2008: Lewis Hamilton (McLaren)

Interlagos: Practice Times

Second practice:

1 F Alonso (Spain) Renault 1min 12.314sec

2 S Buemi (Swit) Toro Rosso 1:12.357

3 R Barrichello (Br) Brawn 1:12.459

4 M Webber (Aus) RedBull 1:12.514

5 J Button (GB) Brawn 1:12.523

6 J Trulli (It) Toyota 1:12.605

7 S Vettel (Ger) RedBull 1:12.611

8 N Rosberg (Ger) Williams 1:12.633

9 A Sutil (Germany) Force India 1:12.720

10 L Hamilton (GB) McLaren-Mercedes 1:12.749 11 R Grosjean (Fr) Renault 1:12.806; 12 R Kubica (Poland) BMW Sauber 1:12.862; 13 K Kobayashi (Japan) Toyota 1:12.869; 14 K Nakajima (Japan) Williams-Toyota 1:12.929; 15 N Heidfeld (Gery) BMW Sauber 1:12.948 16 V Liuzzi (It) Force India-Mercedes 1:12.950; 17 H Kovalainen (Fin) McLaren-Mercedes 1:12.992; 18 K Raikkonen (Fin) Ferrari 1:13.026; 19 J Alguersuari (Spain) Toro Rosso-Ferrari 1:13.041; 20 G Fisichella (It) Ferrari 1:13.275

First practice:

1 M Webber (Aus) Red Bull-Renault: 1min 12.463sec

2 R Barrichello (Br) Brawn-Mercedes: 1:12.874

3 S Vettel (Ger) Red Bull-Renault: 1:12.932

4 H Kovalainen (Fin) McLaren-Mercedes: 1:12.989

5 L Hamilton (GB) McLaren-Mercedes: 1:13.048

6 K Nakajima (Japan) Williams-Toyota: 1:13.067

7 J Button (GB) Brawn-Mercedes: 1:13.141

8 N Rosberg (Ger) Williams-Toyota: 1:13.147

9 A Sutil (Ger) Force India: 1:13.232

10 K Raikkonen (Fin) Ferrari: 1:13.321

11 J Trulli (It) Toyota: 1:13.326

12 N Heidfeld (Ger) BMW Sauber: 1:13.464

13 S Buemi (Swit) Toro Rosso-Ferrari: 1:13.503

14 R Kubica (Pol) BMW Sauber: 1:13.563

15 G Fisichella (It) Ferrari: 1:13.619

16 F Alonso (Sp) Renault: 1:13.787

17 V Liuzzi (It) Force India: 1:13.829

18 K Kobayashi (Japan) Toyota: 1:14.029

19 J Alguersuari (Sp) Toro Rosso-Ferrari: 1:14.040

20 R Grosjean (Fr) Renault: 1:14.173

Drivers' Championship standings

1 Button: 85

2 Barrichello: 71

3 Vettel: 69