Hamilton and Button show McLaren's edge in the wet

Red Bull got their 12th pole position in 13 races today, but behind that headline is an interesting story which gives McLaren some encouragement for the Grand Prix, particularly if it is wet, as it has been every day this weekend.

I spoke with Mark Webber after the qualifying session and he seemed to be more impressed with Lewis Hamilton's improvement of four tenths of a second at the end of the session when the track was wet, than he was with his own pole position. Asking engineers from other teams they share that sense of wonder at Hamilton's final lap. And given that it boosted him to the front row of the grid it may turn out to be an important moment in the championship story. Button too was able to improve in the final run, but not by as much as Hamilton.

McLaren have shown all weekend that they have the fastest car when the track is damp, something we also saw in China, but here it is noticeable that the McLaren is more sure footed on intermediate tyres and on slicks on a damp track.

Hamilton was fastest in the first two parts of qualifying. In Q1 most times were set on the intermediate tyre, although Webber set his on slicks. In Q2 the track was therefore ten seconds faster, but still the McLaren had the edge. Only in Q3 when it dried further and the track was another half second faster again did the Red Bull have the edge.

This could prove quite significant in the race tomorrow if, as expected, the rain continues to come in bursts as it has all weekend.

"They were better than us in Shanghai, "said Webber. "Obviously that was a very consistent condition, it was generally pretty wet. Many things have changed since then in terms of how cars have been developed."

As far as qualifying was concerned, Hamilton did a 1m 46.2 on his first run, at the same time as Webber did the pole lap of 1m 45.7. Then the rain fell on the first corner and yet Hamilton still managed to go four tenths of a second faster on his final run. Team mate Button managed to find two tenths of a second on his final run. At the same time Vettel was 3/10ths slower.

Interestingly Webber and Hamilton were also first and second in final practice on Saturday morning and by a similar margin - a tenth of a second.

There is a lot of talk this evening about Hamilton being in a great position to attack Webber on the long straight after Eau Rouge at the start tomorrow. I've spoken to some engineers about this and there is no doubt that the tow down that straight is worth a lot, as much as 2/10ths of a second. But Hamilton is only one kilometre per hour faster through the speed trap than Webber, so it's not as clear cut as you might think. Once through that phase and into the second sector of the lap, Webber will be able to open up a few tenths of a second gap and settle into his stride. The Red Bull seems to be 0.4s faster in that sector, which is heavily downforce dependent, than the McLaren.

"I don't think tomorrow's Grand Prix will be won and lost on the first lap. I'm expecting Lewis to be pretty close but it's nothing unusual, we've been there before and we will try to do our best, " said Webber.

The performance of Robert Kubica in the Renault is interesting. Although the times today have to be taken with a bit of a pinch of salt, as they are dependent on what time they were set and how the track was at that time, there is no doubt that running the F Duct has really lifted Renault's performance.

Here the engineers tell me that it is worth half a second per lap, probably the most of any track, so that is the gain Renault has made this weekend and it's got Kubica in the game.