Role the Spanish Grand Prix has in showing the state of play in F1
History tells us that the Spanish Grand Prix is an important race on the Formula One calendar, yet the action at the Circuit de Catalunya in Barcelona has rarely supported that view.
Sunday's race will mark the 23rd time that F1 has raced there since its debut in September 1991, but counting the classic races at the venue does not require much time.
If one word were used to describe the Spanish Grand Prix, "processional" would be the most appropriate.
Only once in the past 12 years has the driver who started on pole position in Barcelona failed to stand on the top step of the podium, and you have to go back to the wet 1996 race, when Michael Schumacher overtook Jacques Villeneuve, for the last time there was a pass for the lead on track.
Even with the introduction of the drag-reduction system (DRS) the entertainment has not grown greatly in the past two years, although last year's race was an improvement, with both Sebastian Vettel and Lewis Hamilton making fine comeback drives from down the grid.
So why, given the fact this is apparently such an uneventful race, is it so important?
Because the 4.6-kilometre track, with its fast, long curves, and tight braking areas, is one of the best aerodynamic tests the cars will face in a season.
The venue is used for two pre-season test sessions as teams try to perfect their cars, with the general attitude being something along the lines of "go well in Barcelona, you will go well anywhere".
In 14 of the 15 years before 2012, the car that won in Barcelona went on to win the most races that season.
Last year's race is, on paper, an anomaly. Pastor Maldonado won in his Williams - the only time in the campaign either the Venezuelan or the British team would finish on the podium.
But, closer analysis can partially explain this.
Maldonado started on pole position only because Hamilton, who had been quickest in his McLaren-Mercedes, was demoted to the back of the field after he had run out of fuel at the end of qualifying and been unable to return to the pits under his own power.
McLaren, over the season, arguably had the fastest car.
Yes, Vettel and Red Bull Racing won the titles in the end, but other than a month-long sweet spot in October they did not have the dominance of previous years they had enjoyed
McLaren had the fastest car over the year, matching Red Bull in seven victories over the season, but mistakes like the whopper in Barcelona ruined both Hamilton and their hopes of silverware.
Barcelona can usually tell a team how good their car is. It was here in March that it became apparent that this year's McLaren, which had looked OK in the first test in Jerez, was actually really not OK and that has been backed up by how Jenson Button and Sergio Perez have run so far this season.
As the F1 show arrives in Spain after a three-week break since Bahrain the hope is Barcelona can give us a better idea of the competitive order in 2013.
It may look like the same old story, in terms of Vettel having the lead as he looks for a fourth successive crown, but it has really not been that way.
The Red Bull is quick, but it has been unable to make the Pirelli tyres last long in the races, thus leading to the pace of the car being compromised.
Fernando Alonso and Ferrari have looked to have the best package thus far, but have not been able to make best use of it.
Poor qualifying in Australia left Alonso stuck behind teammate Felipe Massa early on, and the time lost there proved costly in leaving him too much to do in chasing down Kimi Raikkonen at the end of the race.
In Malaysia, Alonso's race was ended by his collision with the back of Vettel's car at the first corner and the mind boggling decision by Ferrari to leave him out with his front wing scraping on the ground. In Bahrain, he was running third before his DRS failure led to extra pit stops and an eighth-place finish.
Only in China has he had a trouble-free run and there the Spaniard was so dominant that his team told him to slow down, such was his speed as he romped to victory.
Alonso and Ferrari are fast, unquestionably, but we have yet to see him go toe to toe with Vettel and Red Bull at the front in a duel between the pair.
Vettel's weakest race was in China when tyre wear led to him go on a safety-first two-stop strategy that ended in fourth place.
In Bahrain, Vettel's tyre problems seemed to have disappeared as he cruised home, well ahead of Raikkonen.
But, crucially, there was no Alonso pushing him, as would have been the case had the Spaniard not been hamstrung by his faulty DRS.
It is much easier to look after your tyres when you have no pressure on you, and Vettel paced himself magnificently in Sakhir.
It would be wrong to ignore Raikkonen, who has won once and finished second twice to be second in the championship, but the Lotus does not have the raw pace of the Red Bull or Ferrari.
An impressive ability to look after their tyres is the biggest asset to Lotus, and with the long sweeping turns of Barcelona notoriously hard on tyres, expect the Finn to be a contender for victory in Spain - but over the season to fall away.
Eventually, the teams will work out how to make the tyres last better, as was the case last season, and then it becomes about who has the fastest package.
The Circuit de Cataluyna normally demonstrates who has the fastest machine and that is why this weekend's duel between Vettel and Alonso is so fascinating, with implications for the rest of the season, even if the race itself is not entertaining.
Come Sunday evening we should have a clearer picture of the competitive order and who will end the year as champion.
Updated: May 9, 2013 04:00 AM