The fastest driver from qualifying doesn’t start from pole position and changeable weather leaves teams with little data when it comes to slick tyre performance, all adding to the unpredictability of the Belgian Grand Prix. So here are a few of the options that are likely to be available to the teams and drivers on race day at Spa…
What’s the quickest strategy?
If you have been following this race weekend since Friday, then you will know that there has been very little in the way of dry weather running. In fact, there has been nothing in terms of high fuel analysis on slick tyres, meaning that the strategic choices have had to be worked out solely on simulations rather than hard data from this weekend.
But the teams know the constructions from earlier races this season to understand how they work on their own cars, and the tyre compounds brought by Pirelli to Spa-Francorchamps are the same as they had here a year ago, so there is some pretty accurate history to work with.
And when all of that is taken into account, a two-stop strategy appears quickest at this point of the weekend.
Given what are likely to be low temperatures (more on that later) and relatively low grip conditions due to earlier wet weather, starting on the soft tyre would give the best performance in the opening laps – and the soft should be able to hold on without high track temperatures for a long enough stint.
Targeting a first stop between Lap 10 and Lap 15, drivers would then switch to the medium for a second stint and add another 15 laps before taking on another set of mediums for the run to the flag.
How about a different option for the top 10?
A slightly more aggressive version of the above strategy includes two stints on the soft compound, which could work depending on how a car is managing its tyres. The first stint will be crucial in understanding what is possible, and a slightly longer run to the first pit stop will help later in the race, but is not essential.
At the first stop the likely switch would be to mediums once again because it opens up flexibility.
Having completed the requirement to run two different tyre compounds during the race, if a driver can then reach Lap 28 they can switch to softs once again – or if that proved too challenging with degradation then the medium remains an option from a few laps earlier.
The benefit of the final stint on softs is increased performance over the medium to allow for overtaking, while it also guards against any light drizzle that might not force a pit stop.
What are the options for the bottom half of the field?
A one-stop strategy could well be seen but it is likely that starting on the medium tyre would be preferred to make this approach work. Although giving up some performance on the opening lap to soft-tyre runners, the medium opens up the ability to run as long as Lap 20 based on the data available, then allowing a switch to the hard compound to the end of the race.
As an alternative approach, a first stint on the softs but with some more tyre management to allow a slightly later pit stop than those two-stopping is also possible, before taking on the hard tyre for up to 32 laps if required. If the softs hold on and are well handled on high fuel, then anything beyond 20 laps before a first stop could also lead to a chance of making a soft-medium strategy work.
It’s not completely out of the question that one or two drivers might gamble on the hard compound at the start to run as long as possible in case rain hits at some stage and everyone needs to switch to intermediate or wet weather tyres, because they would gain position over anyone who had already stopped on softer compounds. But the hard is more likely to be a difficult tyre to manage if there is light rain compared to the soft or medium.
Unlike at many races where the remaining tyre allocations can play a major part in strategic decisions, all of the teams have all of the above options available to them as a result of the lack of dry weather running so far this weekend, with at least two new sets of softs and mediums and one new set of hards still available to all drivers.
Wait, but what’s the weather doing?
This is always a challenging section to write because it really is tough to predict the weather at Spa-Francorchamps, where rain can appear out of almost nowhere. Although rain was forecast at times, that was still the case on Saturday when some heavy showers developed near the circuit in the build-up to the Sprint and caused a delay to the start.
The forecast currently suggests a 40% chance of rain during the race, but there has been an increasing possibility of a shower at some stage, so the teams will be factoring that into their strategic calculations. They at least have plenty of data on how both the full wet and intermediate tyre react this weekend given the wet running on Friday and Saturday, and now know the crossover times when they would need to switch to each tyre.
On low fuel, the crossover point between slick and intermediate is around the 1m53s mark, while between intermediate and full wet it is closer to 2m05s. Those times obviously increase depending on the fuel load in the car, so as a percentage it’s around 108% of a dry lap time from slick to intermediate, and up to 120% intermediate to full wet.
If it stays dry then lower temperatures than the rest of the weekend are expected, with a high of 17C during the race that will make tyre warm-up that bit more challenging but should help with overheating and degradation, again pushing drivers towards the softer compounds available.