Analysis: Did strategy cost Williams the chance of victory in British GP?
The British Grand Prix was exciting once again, even more than the 2014 race, as there was a large element of unpredictability about it throughout.
The British Grand Prix was exciting once again, even more than the 2014 race, as there was a large element of unpredictability about it throughout. Mercedes lost the start to Williams and then rain came towards the end of the race, creating plenty of risk and reward.
It asked a lot of the drivers, but also of the strategists and Race Strategy was at the heart of why the race turned out as it did.
The key question we will address this week is, Could Williams have won the race with different strategy calls?
We will also examine the result of Sebastian Vettel, which also owed a lot to strategy.
Williams 1-2 at the start turns to Williams 4-5 at the end
There has been much speculation about how Williams conducted this race and whether they could have won, or at least collected a podium, given that they had a 1-2 in the early stages of the race. Felipa Massa rocketed between the two front-row Mercedes at the start and then, following a brief safety car period, Valtteri Bottas passed Lewis Hamilton for second place.
Williams had not won Silverstone since 1997 and this unexpected situation definitely presented an opportunity to get a great result.
What made the Williams cars so hard for the Mercedes drivers to overtake was the fact that they were running together, with Bottas the second car not only getting a tow from Massa, but also able to use DRS. Had they split up, with one car acting as a hare, it might have been a little easier for Mercedes to pick the Williams cars off individually.
But team ethos is strong at Williams; they usually refuse to impose team orders, of the kind that Ferrari has used in the past with Schumacher and Alonso.
It soon became apparent that Bottas was faster than Massa in that opening stint. Initially the call from the Williams pit wall was not to race each other, as the management was concerned that this would not only allow the Mercedes to close, it would also damage the tyres.
Bottas made several pleas to be allowed through. We have been here before with races in the early part of last year, like Malaysia, where Massa refused a rare Williams team order to let Bottas through.
Here, Williams did not grant Bottas' wishes, but did relent on their ‘no racing’ policy and told him he was allowed to try to pass. There was clearly quite a bit of discussion going on among key figures on the pit wall, compared to Mercedes' set up, where one man makes all the Strategy decisions.
Had Williams been more cynical (and ambitious) here they would have instructed Massa to let his teammate through as soon as it appeared Bottas was faster and he would have been able to build a lead of over four seconds.
This gap would have protected him from Hamilton’s undercut, which eventually did for both Williams at the first stops. An undercut is where the car behind pits first and uses the performance of the new tyre to leapfrog the lead car when it pits on the next lap to cover the move.
This would have left Bottas ahead in the second stint of the race on hard tyres and would have obliged Hamilton to pass him on track, as it was a one-stop strategy.
Williams were in good shape for this; they had prepared for the hard tyre phase of this race very carefully. Part of their over-arching Strategy for the Silverstone weekend, based on learnings from Barcelona when these Medium and Hard tyres were last used, was to make sure they were as fast and consistent as possible on the hard tyre as this would be the weaker tyre for their main rivals Ferrari and would be used for the longest time in the race.
So that would have been Scenario A and it would have put Bottas in good shape to control the race before the rain came. But he then struggled in the wet as we will see.
Scenario B would have been for them to ask Bottas to hold Mercedes back in certain key points of the circuit, with delayed acceleration out of slow bends and such like, to allow Massa to build the four second gap.
By then pitting Bottas first, in that scenario, they could have protected Massa’s podium.
Massa would have found it harder to pull the gap, as he didn’t have Bottas’ pace, but it was another route they chose not to go down.
Mercedes goes aggressive at the first stop
As Williams did neither of the above scenarios, it made it easy for Mercedes to go aggressive on the timing of the pit stop. This was based on trying to force Williams to run a longer final stint on hard tyres than it might have wanted to. But it was more cunning than that; by timing it as they did on Lap 19, which is on the cusp of the two-stop and one-stop window, it created some doubt at Williams as to whether Hamilton might be planning to two-stop.
Once Hamilton stopped, Williams had to pit Massa and he lost track position, as did Bottas inevitably. So the advantage was lost.
This put Hamilton in the lead of the race, but Nico Rosberg was still stuck behind in fourth, as Hamilton had the priority as the lead car on the timing of the pit stop.
Mercedes asked Rosberg to pass the Williams and to be aggressive, but he could not due to the tow effect outlined above. Only when the rain began to fall did he progress past them and bring himself into play.
Splitting the risk: Rain takes away Williams’ podium chance
At this point, entering the final third of the race, Williams may have lost the chance of the win, but they still had the podium beckoning for Massa. The rain cost them that chance, but again, decision-making was central to what unfolded.
In normal dry running the pit stops are decided by the team strategist. When it is raining, the driver has to play a leading role. There were two rain showers; the first persuaded Kimi Raikkonen to move to intermediates, but it was too early. He had already lost track position to his teammate Vettel.
The second shower was heavier and some teams had the added advantage of weather ‘spotters’ outside the track radioing in information about the timing of the weather moving in.
As the lead car Hamilton had the most to lose from making the wrong decision on when to stop for intermediate rain tyres. The falling temperature of his front tyres prompted him to stop on Lap 43 and it turned out to be exactly the right moment. Vettel had clearly been weighing up a similar move and when he and Ferrari saw the race leader going for it, they drew confidence and went for a stop on the same lap.
Mercedes had to inform Rosberg that Hamilton was stopping and as he had good pace still and there was no point in following Hamilton into the pits on the same lap, as it would offer no chance to win, he gambled on an extra lap on slick tyres. The rain fell more heavily and it didn’t work out for him.
So, in a situation of high uncertainty, Mercedes split the risk. Williams did not do that, instead missing the Lap 43 pit-stop opportunity and pitting both cars on Lap 44.
The gap back to Vettel as the rain fell, was coming down by 3 seconds per lap, so Williams was at increasing risk from him. They lost another seven seconds by doing the extra lap; Lap 44 and Vettel took third place off them.
Williams has had problems with tyre performance in wet conditions and Bottas suffered more than Massa on Sunday. He was faster in the dry, but slower in the wet.
Vettel had been nowhere in the dry conditions, but Raikkonen’s mistake in going too early to intermediates, followed by Williams mistake in not splitting the risk on its two cars, offered him a podium he gratefully accepted.
So, in conclusion, the most likely outcome for Williams, if they had played their cards differently, but without betraying their principles, would have been for Massa to finish on the podium.
Splitting the cars early on in a tortoise and hare strategy would have made the task of overtaking them easier for Mercedes and so it is likely that with a faster car and more aggressive strategy Mercedes would still have won the race, but the extreme scenario of getting Massa to yield to Bottas early on would have made the fight for the lead between the Finn and Hamilton very interesting.
The UBS Race Strategy report is written by James Allen with input and data from several of the leading teams' strategists and from Pirelli
Race History & Tyre Usage Graphs, Kindly Supplied by Williams Martini Racing - Click to Enlarge
Note the substantial pace gap between the Williams cars and the Ferraris, their normal rivals, in the dry conditions (upward curved lines). Note also the reversal of that trend in the wet conditions after Lap 43, Bottas and Massa’s pace falls away while Vettel’s matches the Mercedes.
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