The Spanish Grand Prix this year turned on Strategy; the battle for the victory between the two Mercedes drivers centred on two different strategies, as did the impressive recovery drive of Sebastian Vettel from 15th to 4th and the battle between the two Ferrari drivers, which has been the subject of a lot of speculation.
Here we will clear up exactly what was going on in the strategies of Kimi Raikkonen and Fernando Alonso and why Alonso ended up ahead.
Based on Friday running, it was clear that the difference in performance between the Pirelli medium and hard tyre was around 4/10ths of a second per lap and the tyres were lasting well enough in most cases for the majority of drivers to feel that a two stop strategy was the best way to go.
Simulations showed that two stops was slightly faster for some teams, albeit fairly similar for others. Arguably two stops is less risky with traffic hold ups, however the teams are learning this year with three stops that if you have a new set of tyres and turn up the ERS boost to the maximum with zero fuel saving modes, the gain is over a second a lap. It is relatively easy to overtake, certainly backmarker cars. Sebastian Vettel’s drive was a perfect illustration of that, but he also had some tough overtakes to make.
If a car was not suffering too much degradation, then two stops was fine, as Bottas’ excellent drive for Williams proved.
In the race, eight of the top ten finishers were on two stops.
Rosberg on a different strategy –did it have a chance of working?
The Mercedes was in a league of its own in Spain. Like Bahrain, Rosberg lost the start to Hamilton and was stuck in second place in the early stages. If he did the same strategy as Hamilton he would follow him for 66 laps. He could try to undercut his team mate by stopping a lap earlier, but would be unlikely to be able to make enough of a difference to get the track position.
The preferred option – the Plan B agreed before the race between the Mercedes strategists and the driver – was to switch him to the harder tyre at the first stop and look to attack in the final laps of the race when Hamilton would be on the slower tyre. This increases the pressure on the leader and is more of a psychological challenge, because the gaps are offset and need to be calculated all the time, allowing for the difference between compounds.
It was noticeable in his radio messages with his team about the gap he needed to maintain over Rosberg, that Hamilton sounded quite stressed.
Simulations showed that Rosberg should catch Hamilton with six laps to go, at which point Rosberg would be 0.58s per lap faster. Would it be enough to overtake?
In fact he only caught Hamilton in the final two laps and didn’t really have a chance to attack. This was partly due to being slightly less effective in clearing slower cars (Button and Kobayashi in particular) than Hamilton, who was also able to maintain the gap in at the higher end of the desired range. He was asked to keep the gap at 5 seconds, Rosberg told to get it down to around 2 seconds.
Against that, Hamilton’s stops were both slower than Rosberg’s. His combined time in the pit lane was 46.54 seconds, while Rosberg’s was 44.56 seconds.
Like Bahrain Mercedes gave Rosberg a fair chance to challenge, after he had lost out in qualifying and the race and he said afterwards that he was happy with the strategy he was given. Another time he will know the details he needs to work on to give himself the best shot at beating his team mate.
Red Bull – Vettel getting the hang of 2014 cars
One thing was crystal clear from Barcelona: Sebastian Vettel is now getting up to speed with the handling of the 2014 cars, whose weaker back end due to reduced downforce, gave him little confidence at the start of the year. His recovery drive from 15th place on a three stop strategy was the drive of the day and the strategy relied on him passing a lot of cars.
The key to his 3 stop plan was that, while slower on paper, it offered the chance to have a bigger pace differential at key points of the race. If he had done two stops he would have struggled to make headway.
It was clear what his plan was from Lap 12, when he made an aggressive early stop and then he was able to run in clear air at times at a high pace as well as to turn up engine and ERS and pass cars relatively easily. He was held up by Massa and Grosjean, but neither was able to hold him for long.
He was fortunate however to finish fourth rather than sixth and this was down to Ferrari making a mistake on the final stop with Alonso.
As we shall see, the Spaniard had been switched onto a three stop plan and was running ahead of Vettel on lap 51; both of them having one more stop to make.
At this point, Ferrari should have pitted Alonso to cover an undercut from Vettel, but Red Bull pitted the German first on lap 52 and he undercut Alonso, taking the position away from him. He also cleared Raikkonen, who was two stopping, in the same move. This allowed Vettel on fresh tyres to catch Bottas and gain another position before the end.
Had Alonso covered Vettel’s final stop, by stopping on lap 51 or 52, they would have been on the same strategy, albeit with Vettel on fresh tyres and it would have been hard for Vettel to pass him. After all, Alonso had comfortably held Vettel behind him for 14 laps before Vettel’s final stop.
Ferrari – did they give Alonso the advantage over Raikkonen?
By far the most talked about subject after the race was the strategy moves at Ferrari, which led to Fernando Alonso beating his team mate Kimi Raikkonen to the finish, despite qualifying and racing behind him for much of the race.
So did Ferrari give Alonso the better strategy, as some people are claiming?
The first point to make is that 3 stops was not faster than two. Both drivers started the race planning to stop twice, what happened was that Alonso had higher tyre degradation in the second stint and converted to a three stop at that point.
The contentious question is why did Alonso get to make the first stop on lap 16, one lap before Raikkonen? Normally the prerogative lies with the lead car. There are two explanations for this.
One is that Ferrari was trying to get Alonso ahead with a classic under cut, but if that was the case he did not pull it off. Another explanation, Ferrari’s explanation, is that he pitted first because he was under threat from Massa, who had pitted aggressively on lap 15 and they had to cover that stop with Alonso. This worked and so Raikkonen and Alonso remained ahead of the Brazilian into the second stint. The optimum stop lap was 18, so Raikkonen was the closest to that with his stop on lap 17.
According to the team, Alonso then suffered greater tyre degradation in the second stint than Raikkonen and they wanted Alonso to cover Vettel, who was clearly three stopping, so the team switched him to three stops. Raikkonen was informed of this via radio.
The lap times don’t really show the degradation difference clearly; they are quite similar with Alonso sitting between two and three seconds behind the Finn from laps 17 to 35. But clearly he felt he was losing performance with another seven or eight laps to go to the second stop. The degradation for Raikkonen towards the end of the second stint was damaging for his race effort and opened the door for Alonso to close and pass in the end (see Race History Graph below).
Again the timing of Alonso’s second stop was set by the gap back to Massa, who was clearly three-stopping. Alonso pitted on lap 35 and stayed ahead of his former team mate.
Even allowing for the difference in tyre use, Alonso had slightly better underlying pace than Raikkonen and this meant that the gap between them was only five seconds after Alonso’s final stop, with the Spaniard now back on medium tyres, albeit used ones.
Approaching that third stop, Ferrari also had an eye on Vettel who was just behind Alonso by this stage, however they made a mistake in not covering him, as they had done Massa earlier in the race. (see separate section)
In the final stint, Alonso cruised up to Raikkonen quite quickly, stayed behind for five laps and then passed him.
Raikkonen said afterwards that two stops was the wrong strategy for him, because he was unable to push at the end and because he struggled all race with low grip and poor traction causing degradation.
He was very frustrated, partly because of the way the strategies worked out, but mainly because he was lapped by the winner and he and Alonso were so far off the pace with little sign of a recovery. It is going to be a very long season for the two Ferrari drivers.
Did Ferrari deliberately favour Alonso? It’s not clear that they did. The moves they made were certainly done with others like Massa and Vettel in mind, as Alonso was vulnerable to both.
Bottas’ race shows that two stops should work out better, but Raikkonen’s tyre degradation was worse than expected, as was Alonso’s.
But something was done to overcome that in Alonso’s case and not in Raikkonen’s. Draw conclusions from that as you will.
The UBS Race Strategy Report is written by James Allen, with help and input from several of the leading teams’ F1 Strategists, from JA on F1 technical adviser Mark Gillan and from Pirelli.
Race History Graph, courtesy of Williams Martini Racing
The zero line is the lap time of an imaginary car doing the winner’s average lap speed every lap. It is intended to show the gaps between car performance.
Note the end of Raikkonen’s second stint, the tyre degradation compared to another car, eg Bottas, doing the same two stop strategy. This is where Raikkonen’s race was compromised.
Williams have had tyre degradation problems in the early races, but Bottas’ result of 5th showed that they are getting on top of these issues. If Ferrari had covered Vettel at the final stop, Bottas would have finished fourth, a great effort.
[Click on graph to enlarge]