F1: Button sews up pole again

BrawnGP would have had two cars in the top four but Barrichello trashed his gearbox in his start-line problems in Melbourne. The fitting of a replacement has cost him five places.

So Button has no one riding shotgun away from the line tomorrow.

But his pace in qualifying has been so electric that even though the Toyota next to him is no slouch, so long as he gets away smartly, he should be able to get into the first complex series of corners first - and away up the hill on the long first straight to arrive at the right-hander with as much as half a second in hand.

He knows that hill well: in 2003 he was beating Michael Schumacher, and that hill had much to do with it. But unfortunately, his car broke on the last lap allowing the German to take the place.

Massa will be pleased not to be racing for that right-hander: it was there that Hamilton confused him, leaving him to run wide.

So Button will be aiming to be clear of the field at a point that is, roughly, a third of the way around the circuit.

He stands a good chance of doing so: there will be bunching at the first series of corners - there is a hairpin right, a downhill sweep left and a hard right all within a couple of hundred metres. There is no straight line except off.

And it is usual for at least one or two cars to fail to make the first corner, and a couple more to tangle on the second. The third strings out the field. By the time the leader is approaching the right-hander at the top of the hill, the last cars are usually sorting themselves out at the bottom of it.

But Sepang is a complex and difficult track - in the back complex, that few spectators see and TV does no justice to, there is a sharp left-hander with a steep hill immediately after it. Button is used to such tracks - one of the circuits he raced in karts, Buckmore Park in Kent, has similar features. He used to win there. He know exactly how not to be bogged down at the bottom of a hill.

And Button needs to build the biggest lead he can for Brawn has a problem: the newness of the car and the lack of testing means it's not been out in the wet. Of course, no one has tested their cars in a tropical storm such as Malaysia is suffering at this time of year.

These storms flood main roads - which have massive storm drains - to a depth of several inches in less than ten minutes. Then ten minutes after the rain has stopped, the roads are dry.

Sepang has good drainage but not that good.

For each of the past two years, the race finished at about 4:30. Fifteen minutes later, there was a downpour.

This year, the race starts at 5pm. And almost every day this week, central Kuala Lumpur has had a storm at around 6pm.

Sepang is a very strange place: it has a microclimate. It can be raining like a waterfall two or three kilometres away but the circuit will be bathed in hot sunshine.

Or the opposite.

Button is an excellent wet weather driver: he's calm and smooth.

But, like last year, the cars have no traction control so taming them is tough. And with no wet-weather running, Brawn have no data relating to their current car. They are going to have to extrapolate data from previous years - but the current car has almost nothing in common with the Hondas of the past two years. The aerodynamics have not bee tested in the wet: chucking buckets of water into the wind tunnel just isn't the same, and computer models are fine except they don't say where the puddles are.

So increasingly it looks as if Button's biggest challenge tomorrow will not come from rival drivers but from the weather - and whether his pit crew are up to the job of working out and implementing new settings mid-race. And doing it quickly.

In Melbourne, BrawnGP's pit stops were slow. They can't afford to lose time in the pits tomorrow.

Button needs to be so far ahead of the field by the time it rains that he is not disadvantaged by the lack of wet weather testing and data.