This is our final Strategy Report of the 2011 season, looking not just at how the key decisions were made in Brazil, but also at the trends we have seen in 2011 and what we see as the likely trends for 2012.
The Brazilian Grand Prix brought to an end a season which has seen Formula 1 run to a quite different pattern in terms of Race Strategy, largely due to the Pirelli tyres. But also because the DRS wing has made it easier for cars to overtake, so less time is lost for fast cars in trying to pass slower ones after coming out behind them from a pit stop.
Earlier this season the way the cars used the Pirelli tyres meant that they degraded quickly and the performance of the tyres dropped off a cliff after a small number of laps, forcing multiple pit stops. But as the year went on the teams learned more about how to use the tyres and got longer life from them.
Although it has felt like a year of change, if you analyse the top six or eight starting positions compared to the finish positions, the amount of variation compared to last year isn’t that great; Vettel and Webber normally finish more or less where they start, as does Hamilton Button and Alonso usually make up a place or two, Schumacher qualifies a bit behind but races though to finish where he should have qualified.
So despite the Pirelli tyres and the DRS wings, the outcomes haven’t changed that much, but the way they has been achieved has been more interesting for the spectators because of more overtaking and more use of Race Strategy. So the races have seemed more engaging.
Instead of everyone doing the same strategy, as happened last year, people do different strategies. So instead of everyone running in pace order all race long, cars can rise and fall in positions during the race and there is more shuffling about of the order, which creates crunch situations and battles within the race, such as the Massa /Hamilton scraps or the Alonso/ Webber scraps we’ve enjoyed this year.
If the leading four teams were closer to each other on pace, as the midfield runners are, it would make for some really interesting races. The midfield battle has been really exciting this year with Race Strategy used to make significant gains and here we’ve seen Toro Rosso and Sauber in particular finish well ahead of where they have qualified. Force India have also scored a lot of points from qualifying positions on the fringes of the top ten.
There has been a difference this year between the way different teams have used their tyres. But what has not happened this year is a crossover point between the softer and the harder tyre which offers a range of options as to how to run the race, either taking the longer run on the harder one or the shorter run on the faster tyre, where they cross over.
“What you need is the softer tyres, the super soft and the soft, they need to be fast but degrade,” says Paul Hembery. “The medium and harder tyre need to be slower but be more stable, and basically you have to work how many laps you go before you are better off being on the other one.”
It’s very important that Pirelli achieves the crossover point next year, otherwise the strategies could become a bit generic.
In the final race of the season at Interlagos the teams at the front generally decided before the race that the best way to do the race would be to stop three times, dividing the race into three stints of roughly 20 laps on soft tyres and then a short stint on the slower medium tyres.
Jenson Button did three stops but approached it differently, as we shall examine later.
Several of the midfield teams thought that two stops would be possible and a couple of them pulled it off, with Di Resta and Kobayashi scoring points with the plan
The medium tyre had shown itself to be around 0.8secs a lap slower than the soft in practice and qualifying, but in a race stint it was down to more like 0.5secs for most teams, apart from Ferrari, who really struggled for pace in it again in the race.
Button was pushed into running two stints on the medium tyre because his third set of soft tyres had proved not to be very good on Saturday. When Button went onto the medium tyre on lap 31, he was at the same pace as Alonso on softs. Button did a 1m 16.9 on 3rd lap which looked good and he then ran in the 1m 17s.
The one variation among the top teams was Felipe Massa who did a two stop strategy. He said he was pushed into it by a damaged set of softs after qualifying, but it opened up and interesting option.
It was surprising that Massa hasn’t done this more often this season, because running in sixth place as he usually is, the slowest of the top six drivers, he generally has no pressure from behind and if he does the same plan as the McLarens and Alonso in front of him, he’ll stay sixth.
Here the Ferrari strategists decided to try it and it did allow him to take track position over McLarens for a while so on that level it worked and was worth a try. There is a 71 % chance of a safety car at Interlagos and if one had come in Brazil it would have played into his hands, as would the rain that was forecast, but which never came.
Force India’s Adrian Sutil did a fantastic job to beat the Mercedes of Nico Rosberg for sixth place and they approached the race in quite different ways.
Rosberg did a very long second stint on a new set of soft tyres – 26 laps. He stopped for the first time on lap 16, which is too short for a two stop strategy. But was behind Sutil who had better pace. On a new set of softs he couldn’t keep up with the Force India car. So from that point, if he did a three stop plan, like Sutil, then he wouldn’t beat him.
So the only way he could try to beat him was by doing two stops and trying to get track position after his final stop. It required a very long middle stint on soft tyre.
Although it worked in that he managed to find himself ahead, in the end Rosberg got beaten by a faster car. After the final stops, they found themselves on the same tyre and Rosberg’s tyres were only three laps older, so the plan was great and should have worked, but Rosberg couldn’t stay ahead. The two stop was the right strategy in terms of getting track position but he just couldn’t hold on to the place.
Sutil crammed three stops into what would normally be a two stop window and he managed to keep a good pace. His short stints were an aggressive strategy, but with Massa doing only two stops and not being as quick as he would normally would be, at one point he came back towards Sutil and almost impacted on Sutil’s race, as you can see on the race history graph below.
The Force India was very quick this weekend. Paul Di Resta hadn’t done as well in qualifying and so the team put him on a two stop plan. He was racing Petrov and Kobayashi and easily won that battle.
Di Resta’s two stop was a defensive strategy, like Rosberg’s because it will give you track position after your second stop and then it’s a question of whether you can keep your opponent behind you.
The UBS Strategy Report is prepared by JA on F1 with input and data from several F1 team strategists and engineers.
RACE HISTORY GRAPH