A reminder of how they line up.

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"Quickest strategy on paper for the 66-lap race is a two-stopper. Start on the soft tyre for 22 laps, do another soft stint for 23 laps, then medium to the end.

"Teams will probably aim for a one-stopper though: especially as it’s quite hard to overtake. The theoretically fastest one-stopper is: start on the soft tyre for 27 laps (managing it carefully) and then switch to the hard until the finish.

"A less marginal strategy – which is quite close anyway on overall race time – is to start on the medium for 30 laps, then switch to the hard for the final 36 laps. However, nobody in the top 10 of the grid will be able to try this."

Here's our track. Romain Grosjean wiped out Nico Hulkenberg and Pierre Gasly at Turn Three here last year. More opening lap drama coming up?

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Will Max give his fans something to cheer about? He won at the age of 18 years and 228 days in 2016 when the two Mercedes banged into each other.

Why do Formula 1 drivers need to keep fit and how do they do so?

Williams driver George Russell tells us how not to let your head feel like it's going to fall off your shoulders during an F1 race, along with all the other ways to keep yourself in shape - if you're a racing driver.

Andrew Benson
BBC Sport’s chief F1 writer at the Circuit de Barcelona-Catalunya

Image source, Getty Images

A chink of light for Williams at last? They are alone in not bringing upgrades to this weekend, a result of the need to build new parts to replace the ones smashed in two big crashes in Baku. But George Russell was just 0.4secs off the back of the midfield - Antonio Giovinazzi’s Alfa Romeo - the closest it has been all year.

"The fact that everybody has brought their big upgrades and we haven't really brought anything to the car, just a few little test items to try to understand the car better, is encouraging,” Russell said. "Perhaps we optimised for qualifying more than the guys just ahead of me did but there's no reason yet we can't be on the back of them in the opening laps and see what happens later in the race. But at the moment we're just being realistic. It would be silly to go out there and expect points or anything, so we have to go out there and use each session as a test session really and try to understand stuff for later in the year.”

Robert Kubica was a massive 1.2secs off, struggling with oversteer and confused.

Benjamin Lee‏: Think that grid is pretty reflective, for all the talk, of where each team really is in terms of performances and development this season. Can't be the only one pretending to be completely engrossed in this race to distract from what's about to happen at 3pm...

Karen Waddy: Don't envy Vettel being between sandwiched in between two Mercedes drivers who might not be playing nicely any more and Mad Max!

Watch as Nico Hulkenberg takes a trip to the gravel...

Andrew Benson
BBC Sport’s chief F1 writer at the Circuit de Barcelona-Catalunya

Image source, Getty Images

It has been another difficult weekend for Renault. The car has lacked pace all weekend, and Daniel Ricciardo only just scraped through into the second qualifying session, while Nico Hulkenberg did not get out of Q1. The German did not help himself with a crash at the start of Q1, which required a new front wing. The new one was the old specification, which Hulkenberg himself admitted to the broadcast media straight after qualifying. But he then changed his tune when speaking to the written media, saying it was the same spec. FIA technical director Jo Bauer reported them to the stewards for the technical discrepancy and Hulkenberg has to start the race from the pit lane. Renault initially claimed to the stewards the wing was of a “similar” spec but accepted the verdict.

Ricciardo did make it into the top 10 - by the skin of his teeth over McLaren’s Lando Norris. But has a three-place grid penalty for his crash with Daniil Kvyat in Baku. And on average over the season the Renault remains at the back of the midfield on pace - even if this result moves them fractionally ahead of Alfa Romeo into eighth-fastest overall. This is not good news for a team that started the season with ambitions of closing on the top three.

So how did Valtteri Bottas get himself on to pole for the third race in a row? This is how...

Listen live to commentary of the Spanish Grand Prix from the Circuit de Barcelona-Catalunya with our team of Jack Nicholls, Jolyon Palmer and Jennie Gow.

Coverage starts on BBC Radio 5 Live sports extra but you can tune into uninterrupted coverage via the audio icon at the top of this page from 14:00 BST.

Max Verstappen, speaking to Martin Brundle on the grid says he's feeling happy.

"Compared to Ferrari we have a chance. We will try to take a position but if not then not. We'll try and have a good race and see what we can do on strategy."

Andrew Benson
BBC Sport’s chief F1 writer at the Circuit de Barcelona-Catalunya

Image source, EPA

Charles Leclerc was a disappointed man after qualifying. All weekend, he had been nip and tuck with Sebastian Vettel, perhaps shading him by a fraction. But it all went wrong when he ran wide at Turn Nine in Q2. That not only meant another run on another set of new tyres to get into the top 10 shoot-out, but also only one set of tyres for Q3, and a damaged car. “In Q2 I don’t really know how I could lose that much the car on the kerb,” he said. “I did not expect it.

"I had a bit of understeer but I kept it flat thinking it would be fine, but we broke quite a lot and in Q3 the balance was very strange so we need to check the car. But we were slower than Mercedes and that’s it.”

Leclerc keeps making these qualifying errors. Little ones in Australia, China and Spain prevented him being on terms with Vettel and of course there was the crash that ended his hopes of what looked a near-certain pole in Baku. If he can iron them out, the Ferrari team could become his. But he needs to do so first.

Everyone loves a good underdog story. Well Spain was the setting for one of the most unlikely race winners in Formula 1.

Send your minds back to 2012 and the time when Pastor Maldonado got himself his one and only race win.

That's right, a driver who ended up with the nickname 'Crashtor' because of his incredible ability to send his car into the wall or a rival car, but in 2012 there he was, race winner.

He was a bit lucky to get himself on to pole as Lewis Hamilton qualified first but was sent to the back because of a fuel infringement and 66 laps later Williams' driver Maldonado had held off the home challenge of Fernando Alonso to take the victory -the Venezuelan's only podium finish in his 95-race Formula 1 career.

Imagine the craziness that has to happen over the next two hours for there to be a Williams winner today?

Image source, Getty Images

Honda's F1 technical director Toyoharu Tanabe celebrates his birthday today at the Circuit de Barcelona-Catalunya.

It seems the team at Red Bull had an office whip-round and bought him this lovely cake, with a big Honda badge on it. Hopefully there is still a slice each for Max Verstappen and Pierre Gasly by the end of today's proceedings.

Image source, Getty Images

Image source, Getty Images

Kayleigh: Quickly little prediction before I go back to work. Bot for the win, Vet to be the meat in the Merc sandwich, Ham P3. Points for Norris and Hulk and Ric! Hope it’s a good one.

Jeremiah Kariuki‏: The BBC F1 updates say "today is the day"! Indeed, besides being about Bottas and Hamilton, it could be the day Ferrari team orders fail dismally again, and Leclerc get's onto the podium at the expense of Vettel.

Lisa Higgins: If Ferrari don’t start making inroads into Mercedes dominance Hamilton and Bottas will be driving off into the distance with the championship. They have been pressured into errors, so much promise but yet again Ferrari have shown fragility and tactical naivety!

Andrew Benson
BBC Sport’s chief F1 writer at the Circuit de Barcelona-Catalunya

Image source, Getty Images

Can Ferrari do anything about Mercedes in Spain? It didn’t look like it through the weekend - they were way off the pace on both single-lap and long runs. But Sebastian Vettel remains optimistic and said he saw some hope as a result of changes to the car he made for qualifying.

“We tried a lot of stuff yesterday, and again today,” he said on Saturday. “Different directions. I think we ended up getting the best out of the car for today, which, as I say, wasn’t enough and we’re certainly not satisfied – but I’m very happy with the approach, with the chance that we took, in terms of trying something daring, something I think ultimately will pay off. But hopefully it helps us in terms of pace (in the race). Hopefully sets off the right direction for the next couple of weeks.”

Hang on, what's going on here?

Former Real Madrid defender Alvaro Arbeloa has snuck on to Barcelona turf to present McLaren driver Carlos Sainz with a Real Madrid shirt.

One footballer who won't be completely absorbed by today's Premier League title race is Paris St Germain forward Neymar.

The Brazilian, who used to ply his trade in Barcelona, is enjoying the scenes around the Circuit de Barcelona-Catalunya with fellow superstar Dani Alves, stopping off for a visit to Red Bull's garage for a snap with Red Bull's Team Principal Christian Horner and a chat with driver Pierre Gasly.

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images