Just before this Formula 1 season started, we were set to have a winner takes all championship – whoever won most races would win the world title. It seems like a lifetime ago, doesn’t it?

It’s just as well we didn’t though. One of the worries about that system was that one of the Brawn GP drivers could dominate the early part of the season, and seal the championship regardless of their later performance. Well, that’s just about happened, hasn’t it?

With four races to go, Rubens Barichello and Sebastian Vettel – with a pair of wins each – would both be in with a chance of the title. But with Jenson Button on six wins, one of them would need to win every one of those four races.

So the championship is more open than it would have been under the winner takes all format.

Vettel and Mark Webber are both less than 30 points behind Button, with 40 left to play for, but really it’s Barrichello, just 14 points back in second, who has the most realistic chance of overhauling Button. That’s the same Barrichello that I confidently wrote off back in April.

Earlier in the season, I thought that Button’s greatest threat would come from other teams improving, but that he might hold on to his advantage if they fought amongst themselves. Actually it’s his team-mate bothering him, but he’s still being helped by Hamilton, Raikkonen and the Red Bull Racing pair having taken points off Barrichello at various points in the season.

It’s probably going to take Barrichello dominating the closing part of the season, in the manner than Button dominated the opening part, for him to take the title. It doesn’t sound likely, but neither did Button’s early dominance.