Why F1 turned upside down

What we are left with then is a Force India and a BMW that have jumped from knocking on the door of final qualifying to artificially topping it and a McLaren that went in the opposite direction.

Both the Force India and BMW had shown very real improvements prior to Spa.

At Valencia the previous week, BMW's Robert Kubica graduated to the shoot-out and beat Webber's Red Bull to eighth in the race and Adrian Sutil qualified the Force India a solid 12th.

The difference between the fastest car in second qualifying and 12th these days is typically around 0.5 seconds or less. So we are not talking about a night and day difference.

McLaren came to Spa absolutely not expecting to figure strongly, knowing that their continuing lack of fast-corner performance was not going to allow them to take up where they left off around the slow- and medium-speed twists of Hungary and Valencia.

Nonetheless, while accepting all these provisos, the Force India and BMW were suddenly a lot more competitive at Spa, at least as fast as a Ferrari, despite no major developments since a week earlier.

This is largely to do with the very different aerodynamic demands of Spa to any track F1 has visited this year so far and how that suits some cars better than others.

Spa is the first truly low-downforce track of the season, one of only two (Monza, where the Italian Grand Prix will be held on 13 September, being the other).

The long straights of sectors one and three demand that a car has good straight-line speed, so the necessary wing level for the optimum lap time is much lower than anywhere else so far this season.

However, different cars will hang on to different proportions of their downforce when wing levels are lowered. Downforce is not only derived from the wings but also from the bodies and underbodies of the cars themselves.

Each design will have its own unique point of trade-off between straight-line speed and lap time at each track, and the competitive order between the cars will vary along with the demands of a given track.

The demands of Spa being so different to the other tracks to date simply revealed that the cars have a different order of performance relative to each other when wing levels are lowered so far.