Playing F1 chess against itself: McLaren’s strategy calls

Lap 11 of the Belgian Grand Prix and the initially wet track was drying out. Oscar Piastri and Lando Norris were separated by less than 2sec and Piastri was around 10sec clear of third place. So the McLaren pitwall had margin in hand as they tried to decide the optimum moment to switch to slicks. They watched carefully as Lewis Hamilton, Nico Hülkenberg and Pierre Gasly all came in at the end of that lap and exchanged their intermediates for medium compound slicks. Hamilton’s sector times confirmed it was ideal, but the McLarens were by now towards the end of lap 12. Piastri was told, with little notice, to pit. He did so and was fitted with a set of mediums.

In theory they had enough of a margin over Leclerc in third to have brought Norris in on the same lap and stacked him for a couple of seconds behind Piastri. But both drivers had discussed in that morning’s meeting there would be the option of the second-placed driver choosing the hard C1 compound in just such a situation. It was the less appealing option on paper – as the hard was two steps harder than the medium and was probably going to be relatively slow. Pirelli had made this two-step differentiation precisely to try to ensure any dry race would not be a dull one-stop. But as the second driver, it had an appeal: it offered the prospect of doing one stop less than the guy in front. That would be a 21sec saving right there.

Accordingly, Norris was told by his engineer to pit opposite to Piastri – ie: stay out if Piastri pitted, but come in if he didn’t. Norris understood what this meant, as it had been discussed beforehand. If he’d been stacked behind Piastri, the only tyres ready were the mediums. So he’d be on the same strategy. Once Piastri pitted, the hard option made even more sense for Norris, as he would lose around 7sec with his in-lap on the worn inters compared to Piastri’s out-lap on new slicks.

Once informed that Norris had chosen the hards, Piastri knew that his task was to get the mediums to last the remaining distance while maintaining a pace good enough to prevent Norris getting into his DRS range before the end. If, by around lap 30 of the race’s 44 laps, he had a pitstop’s-worth of gap over third place, then there was another possibility for Piastri if his tyres were not holding up: he could make the second stop, exit in second place and try to use his fresh tyre advantage over Norris to close him down and re-pass. He did indeed have the required gap over third by lap 30 and if he’d chosen to pit then he’d have been 11sec behind with 14 laps to go on tyres 17 laps newer. It was feasible. But not preferable. Piastri judged it to perfection, stayed out there to let Norris do all the pushing.

“I would have chosen the hards too if I’d been second,” said Piastri. It offered the possibility of a win from the unfavoured position.

McLaren is essentially playing chess against itself. All it can do to ensure fairness is prioritise the lead driver and allow the other to try an alternative strategy. Piastri had put himself at the strategic advantage by being the lead driver at the pitstop window.