David Coulthard's Korean Grand Prix preview

Jackie Stewart contends that it's more difficult to defend the world championship than to win it for the first time; that after you reach the pinnacle once, you can struggle. In the case of Mika Hakkinen, my title-winning McLaren team-mate in 1998 and '99, he went away at the end of the season elated with his first title, but he was deflated in the first part of the following year before he rebuilt the energy to go for it again.

So what Sebastian Vettel has done in winning back-to-back world championships in so dominant a style is remarkable. It's as if being champion last year has allowed him to unlock something and move to another level. He does make mistakes - and there have been crashes during Friday practice, as we saw at Suzuka - but very few. He's stepped up, while by contrast Mark Webber has struggled and never had the rub of the green.

Qualifying at Suzuka was a great example. It seemed that McLaren had the edge, but Seb dug deep and delivered an incredible qualifying lap. He is absolutely focused, is not living the rock-'n'-roll lifestyle, and that's reflected in his performances. And there are more wins to come, even though he couldn't clinch the title with the victory he wanted.

The fight for second

You can argue that second in the championship is the first loser, but it really does matter. Look at the situation Jenson Button is in: if he finishes second in the championship, it means he beats Lewis Hamilton. It would be the first time in his career that Lewis has been defeated over a season by a team-mate, which would represent a genuine turnaround.

I suspect Jenson started his McLaren journey knowing that Lewis was a little quicker over a single lap. The first season probably cemented that belief. But now that has to be reassessed. It's as if he has discovered some new speed. Is it because Lewis has lost some because of the negativity over what's happened this season? Possibly, as it's clear that Jenson is far more relaxed than he is. Remember, Jenson used to get a little frustrated by the car in qualifying and then deliver in races, which is often what happened to me at McLaren.

But that isn't the story anymore, as he showed with his win at Suzuka. So it would be massively significant for him to take second place - and vice versa for Lewis to take it off him. Jenson could have number three on the car next year, which suddenly puts him in the position where he gets that position in the garage and his name is listed first in the race programme. Those small psychological things do make a difference.

Button is full of confidence after Japan win © LAT

Momentum counts

The battle for the world championship may be done and dusted, but the run of four races that starts in Korea this weekend still matters to everybody.

Momentum is crucial. Top teams such as Red Bull, McLaren, Ferrari and Mercedes have the resources to develop this year's car in parallel with next year's. There are changes in the rules for 2012, mainly related to the ban on exhaust-blown diffusers, but the rest is largely stable. So if you come up with, say, a new front wing that's more efficient in the last race of the season, you can carry it forward into next year.

There is also the commercial benefit of finishing as high up the constructors' championship as possible, and the fact that finishing on a high boosts the whole team. McLaren has made huge progress since the start of the season and was very competitive at Suzuka, where everyone expected Red Bull to be comfortably ahead, and that could be significant for next year.

The drivers' championship is gone, but there is still plenty to race for.