BBC F1's fuel-adjusted Spanish GP grid
Jenson Button grabbed all the headlines in qualifying at the Spanish Grand Prix when he grabbed pole with his scintillating last-gasp lap - but it was Red Bull's Sebastian Vettel who was actually the fastest man in the field.
The drivers in the top 10 shoot-out are not allowed to refuel between qualifying and race, so their performance is dictated to some extent by the amount of fuel they have on board.
And once the weights of the cars are published it is possible to work out who has done the best job in qualifying.
It turns out that Vettel, who qualified second, is carrying 5.5kg more fuel than Button - enough for him to be able to do two more laps before his pit stop - and that once the weights of the cars are taken into account, he was fastest by 0.059 seconds.
Every extra kg of fuel costs a Formula 1 car 0.035 seconds around the Circuit de Catalunya, and a car uses an average of about 2.4kg of fuel per lap.
Once that is taken into account, the Spanish GP fuel-corrected grid, with estimated first pit-stop laps, looks like this:
1 Vettel - lap 16
2 Button +0.059 seconds - lap 14
3 Massa +0.151 - lap 17
4 Barrichello +0.172 - lap 15
5 Webber +0.389 - lap 16
6 Trulli +0.454 - lap 16
7 Glock +0.762 - lap 14
8 Alonso +0.959 - lap 13
9 Rosberg +1.321 - lap 23
10 Kubica +1.728 - lap 19
That suggests it could be a really close race on Sunday - with Vettel, Button, Felipe Massa and Rubens Barrichello all very evenly matched, and Mark Webber potentially in the mix as well.
The start should be especially intriguing. With the Kers power-boost and energy storage system on his Ferrari, Massa could easily leapfrog ahead of Button and Vettel on the run down to the first corner.
And once a car is ahead in Barcelona, it can control the race. Not only that but Ferrari clearly have genuine pace for the first time this season - and Button has said the car looks quick on long runs as well.
Could the stage be set for the first Ferrari win of 2009? If so, that would be a quite incredible turnaround after such a disastrous start to the year.