Why a three-stop strategy could be the winning plan for Spanish GP

There are plenty of varied strategy options on offer to teams for Sunday's 66-lap Spanish Grand Prix, at a baking hot Circuit de Barcelona-Catalunya.

Air temperatures could reach as high as 30 degrees Celsius at the circuit, pushing the track temperatures towards the 50s.

That could play havoc with tyre degradation, leaving drivers forced to protect their rubber as they fight it out for the win or switch to an alternative strategy.

Medium tyre will play big part in the race

The majority of teams will be looking to complete the race on a two-stop strategy, with the Medium C2 compound likely to be the tyre that most drivers start the race on. By doing so, teams allow themselves some flexibility with their strategy, opening the door for them to switch onto either a one-stop or a three-stop, should they wish.

That tyre is expected to be key for the race. Most outfits on the grid pushed it to its limits on Friday, with some reporting that they were surprised by its durability, even in hot conditions.

Pirelli were expecting teams to protect their Medium tyres throughout the weekend, so as to ensure they have two sets available to them on race day. Mercedes, Red Bull, Alpine, Williams, Alfa Romeo and Ferrari have done exactly that, while McLaren, Haas and AlphaTauri have just one set of new Medium tyres left.

But Aston Martin have gone against the curve and could start the race on the Hard C1 compound, with both Lance Stroll and Sebastian Vettel counting just one set of used Mediums heading into the race.

When will teams make a call on stratergy?

The teams will be looking closely at degradation during the early laps of the Spanish Grand Prix, as they look to discover whether the race will play out to be a two-stop or three-stop affair.

Heading towards lights out, the two-stop strategy appears to be more likely, but all will hinge on how the race-starting tyres cope during the first 15-28 laps in the Barcelona heat. That is the window in which Pirelli are expecting to see teams box for new tyres, with their compound choice likely to offer big hints as to which strategy they have decided upon.

The quickest route to the chequered flag, according to Pirelli, will be to swap the race-starting Medium tyres for another set of Mediums, before ending the race on the Soft C3 compound. However, teams could opt to swap Mediums for Softs at their first pit-stop, leaving the door open for a three-stop strategy that would see drivers run three sets of Soft tyres to the finish.

Of those inside the top six, only pole-sitter Charles Leclerc boasts a new set of Soft tyres heading into race day, while his rivals count three sets of used Soft tyres each. That could work in the Monegasque's favour, should the temperatures soar in Barcelona.

What other strategies are on offer?

Pirelli have also predicted that some teams could use the Hard tyres midway through the race to cope with degradation, by prolonging their middle stint and ending the race on the Soft tyres.

Here are the possible race strategies, as outlined by Pirelli, and the tyre sets that each driver has available to them for the Spanish Grand Prix: