Post-Race Analysis: Turkey 2020 — A Fitting Race for a Historic Moment
By: Ekagra Gupta
Tags: Formula 1, Strategy, F1, 2020, Data Visualization

Figure 3 above displays the fastest lap completed on every lap of the race as well as what tyre compound was used for that lap time. For the Inter’s 1–3, these refer to the subsequent intermediate tyres used after each stop (i.e. Inter 2 is the 2nd set of intermediate tyres used by that particular driver who set the lap time). Additional to this are fitted values from regressions based on the same lap time data. This is to highlight the trend over that tyre stint.

The key aspects of the chart are the comparisons between the lap times of wet tyres and the first set of intermediates as well as the comparisons between the first and second set of intermediate tyres.

Charles Leclerc was the first driver to set a competitive lap time on intermediate tyres on Lap 9. The lap time was almost 3 seconds faster than the previous time set on the wet tyre by Alexander Albon. And whilst both Williams’ drivers had started the race on intermediates, their lap times were materially slower than the wet runners. However, from Leclerc’s Lap 9 time, it was a clear decision to move onto the intermediate tyres — as most competitor’s did within the next few laps.

Things Unravel for Stroll

The next crossover point is less obvious. The first competitive time from a 2nd set of intermediate tyres come from Max Verstappen. However this was an unplanned stop after suffering from a spin that flat spotted his tyres. The next set of reliable data points came once again from Leclerc on Lap 32. For the next 10 laps there was a back and forth battle for the best lap times between new intermediate runners and old intermediate runners. Assessing the trend lines for both these compounds in Figure 3 above shows a period of overlap where is it very unclear as to which tyre is superior.

To add more to the strategic headache, the faintest of dry lines was beginning to form on track — albeit surrounded by many wet patches and puddles. The carrot was there for all the teams to risk it on slick tyres and jump the field. However, any mistake or excursion off-line would be almost certain peril.

This is what Racing Point were holding out for with Lance Stroll — who was losing time and struggling on his worn intermediates. Ultimately, assessing the crossovers at the time, they made the call to pit Stroll on Lap 36 — corresponding to the crossovers in Figure 2 above. Things only went from bad to worse for Stroll as suspected damage contributed to accelerated graining on his new intermediate tyres. As such, he was never able to get the same performance and went back down the order.

Hamilton Avoids Stroll’s Fate by Creating a ‘New’ Tyre

So how did Hamilton manage to win the race on an old set of intermediates whilst many other drivers were improving on a new set of tyres?

As mentioned earlier, the call to move to new intermediates was tense and marginal. Hamilton had expressed over the radio his doubts that the track would ever be suitable for slick tyres as well as concerns around keeping optimal tyre temperature in a new set of intermediates. Hence the decision was made to go long on the intermediates with the ambition of wearing out the grooves and transform the tyre into a de-facto slick tyre.

The advantage of this is that the intermediate and wet tyres are often much softer than even the softest dry compound tyre — and can hence give you more grip at a lower temperature band. And since the track had evolved to an ‘almost’ dry state, putting new intermediates through an initial heat cycle is risky since it takes time to build in heat and others had already suffered graining issues. The downside of Hamilton’s strategy is risks around tyre integrity and reliance on the heat of the tyre to provide you grip moreso than the remaining tread. Anything that causes a loss in temperature could be catastrophic.