The Bahrain Grand Prix was another example of close racing with uncertain outcomes, dependent on race strategy, which has already come to characterise the 2012 F1 season.
Sebastian Vettel and Red Bull became the fourth different car/driver winning combination in four races, showing not only how closely matched the teams are, but also how delicate the balancing act is in getting the strategy right on the Pirelli tyres.
In just four races we have already had eight different drivers on the podium, more than in the whole of 2011.
Bahrain’s Sakhir circuit provided the sternest test yet of the tyres, with plenty of high energy corners, hard braking zones and track temperatures around 40 degrees.
Tyre degradation was very high, especially due to the heat. Degradation is a measure of the decline in lap time performance, whereas wear is the consumption of the tyre.
Strategists briefed on Sunday morning that the wear was not a problem – it would be possible to do a whole race distance on one set of tyres – but the drop-off in lap time was severe over 20 or so laps on the medium tyre and 14 on the soft.
So it was a question of being reactive. It was essential to have a plan in mind, whether that was two stops or three stops, but to be prepared to change it, reacting quickly to pit once you saw degradation affecting the lap time. There was also a huge benefit in having new sets of tyres, rather than used sets.
Pre-race expectations were that most drivers would do three stops, with a few trying a two stop strategy. In the event, among the top ten finishers, only Force India’s Paul di Resta managed to do two stops.
There were many surprises in this race. The poor performance of McLaren on track and in the pits, for example. But the biggest was the way the Lotus cars of Kimi Raikkonen and Romain Grosjean took on the Red Bulls. They managed to beat Mark Webber fairly easily, but Raikkonen couldn’t quite do enough to beat Vettel to the win.
Lotus has had a good car at every race this season, but hasn’t quite got the strategy right before. In China, for example, they tried to do a two stop race with Raikkonen, but timed the stops wrong and on worn tyres he was vulnerable to the three stoppers at the end of the race, falling from 2nd place to 14th.
In Bahrain they got it almost perfect. The strategy planning began in qualifying, where the Finn did only one lap in the Q2 session, intending save a new set of soft tyres. Here Lotus made a small mistake, which turned out to be a benefit as they sent him out too early and underestimated the track improvement at the end of the Q2 session. Raikkonen failed to make the top ten shootout, where Ricciardo’s result shows that a 6th place start might have been possible for the Lotus. But to do that would have used up more tyres.
It wasn’t their intention to miss Q3, however the upside was that by failing to make the top ten, it meant Raikkonen had two new sets of soft tyres and two new sets of mediums, so he would do the whole race on new tyres. He also had a free choice of starting tyres. Vettel, in contrast, by going all the way to the end of qualifying and taking pole, used all his tyres except for one set of mediums and was forced to start on used softs.
How much was the gain from this on Raikkonen’s side? Every new set you run compared to your rival on a used set is worth around 8 seconds for a stint. Here’s how the strategists work it out: Degradation is 0.3 seconds per lap, so after 3 laps in qualifying on a set of a tyres they is 0.7s per lap slower than a new set.
So for Raikkonen compared to Vettel, in the first three stints there was 24 seconds available to him, provided he could make use of the new tyres and not lose time with mistakes or in traffic. It’s what got him in the game and almost won him the race.
Lotus went for the soft tyre for the start, because it has a higher working temperature than the medium and free practice had shown the car worked well on it with high fuel. They thought they were the fastest car on Friday.
We’ve seen how the start is crucial in strategy terms and Raikkonen made a great start, showing the advantage of new softs tyres off the line, up from 11th to seventh and ahead of Rosberg and Perez. He made a mistake on lap three and let Massa past, taking a couple of laps to get back past him again. During this time he lost three seconds to the leader Vettel. But more significantly he damaged his front wing and so had to deal with some aerodynamic loss, which also cost him for the rest of the race.
Thanks to the new tyres he passed Hamilton, who was struggling, and he managed to extend the first stint to lap 11. By doing this he got ahead of Alonso, Webber and Button. Now he was a contender for the win.
In the second stint on new softs he was the fastest car on the track until he caught his team-mate Grosjean and it was here, arguably, that he lost the chance to win. Vettel was not getting away at the front, Grosjean was on used medium tyres and Raikkonen was caught up behind him. He passed the Frenchman then set off after Vettel.
On new mediums compared to Vettel’s used softs he caught up quickly, but couldn’t pass. With some clear air instead of the four laps he spent behind Grosjean, he might have had the platform to jump Vettel in the final stops, but instead he made his third stop on the same lap and with Vettel using his only new set of tyres in the final stint, Raikkonen had no further tyre advantage to play and had to follow him home.
Raikkonen was disappointed after the race. He had a chance to win, just as Perez had a chance to win in Malaysia. The strategy was good enough to give him a chance, but not perfect. Perhaps with a little more ruthlessness by Lotus, moving Grosjean aside, it could have been perfect.
After a trying weekend off the track the Sahara Force India team got a great result on Sunday with Paul Di Resta finishing sixth. As the Scotsman said afterwards, this felt like a win for the midfield team.
He did it despite having the slowest car of the top 12 qualifiers, with a pace offset of 8/10ths of a second per lap to the Red Bulls and McLarens and 3/10ths to the Mercedes.
Again the strategy planning began in qualifying; the team had taken the decision not to do a lap in Q3 but instead to save tyres for the race, knowing that he was going to try to do a two-stop race. This gave him two new sets of soft tyres and one new set of mediums for the race.
The ideal two stop race was to stop on laps 19 and 38, but even though he had new soft tyres at the start, he couldn’t get further than lap 14 before the degradation became too great, relative to the three stoppers, and he had to pit. He was the last of the top ten to do so.
With everyone around him three stopping, Force India knew their driver would be vulnerable at the end of the race on worn tyres to three stoppers on fresh tyres, but Di Resta drove a masterful race, keeping the tyres alive at the same time as keeping the pace up.
On new softs at the start, he lost two places off the line and lost time behind Senna. However, by extending his soft tyres to lap 14 he was able to get ahead of many of the three stoppers, including Rosberg, whom he was racing for final position.
Traffic is less of a problem for a two stopper than a three stopper, but Di Resta still lost time at various stages of the race, particularly the second stint where he was faster than many three stoppers, despite looking to do a 19 lap stint compared to their 13 laps. If there was a place where he lost the opportunity to finish ahead of Rosberg, it was probably here.
With a final stint of 24 laps, he was vulnerable at the end of the race, to Rosberg, but was helped by Button’s late race retirement and the fact that Alonso didn’t quite have the straight line speed to attack in the final laps. Using KERS, Di Resta could defend and hold his 6th position, equalling his career best F1 finish.
The UBS Race Strategy Report is written by James Allen with input from F1 team strategists and from Pirelli.