F1: James Allen Strategiereport – Bahrain 2013

The Bahrain Grand Prix was another race packed with action and incident, the outcome heavily influenced by race strategy.

The drivers who finished in the top ten tried a wide variety of strategies to attain their result, working around the limitations of the medium and hard Pirelli tyres and the intensely high track temperatures. The DRS wing technical problems encountered by Ferrari’s Fernando Alonso, who started third on the grid, meant that it was a relatively easy win for Red Bull’s Sebastian Vettel. But behind him, everyone else was reliant on strategy for their result as we shall see.

The decision for most teams was whether to make two or three stops, but a surge in track temperature an hour before the race to 50 degrees put a few teams off the idea of doing two stops.

The restriction in Bahrain was not tyre wear, as at other venues this season, it was drop off in performance due to overheating tyres. So the question was whether a driver could be consistent over the length of a stint.

The hard tyre was the preferred race tyre for most. However, because most teams did not feel confident they could be consistent over the race with just two stops (three sets of tyres) they went for three stops, it led to some furious racing action on track as the drivers had to come through and pass other cars on track to make their strategies work.

Lotus – same outcome as last year

Last year Lotus went away from Bahrain with second and third places thinking that they could have won the race. This year the outcome is similar, but could they have challenged Sebastian Vettel for the win?

It is very difficult to say whether Raikkonen would have won the race had he started in the front two rows of the grid, where the team expected him to qualify, especially after the penalties for Webber and Hamilton.

Although the pace of the car in the race was as strong as any car, the problem for Lotus, once again, was the qualifying performance. Last year the car wasn’t strong in qualifying trim, this year the drivers were not able to match their Q2 times in Q3, where the grid places are handed out. Had Kimi Raikkonen simply repeated his Q2 time in Q3, he would have started fifth on the grid instead of 8th. Had he improved by a few tenths, as he did in China and as most drivers did in Bahrain, he would have started 4th in front of Massa and could have mounted a challenge for the win.

From 5th he would have done the race on a three stop strategy, which was the fastest this year in Bahrain and had a go at challenging Vettel.
But from 8th, he was forced to do a two stop strategy because the team knew he would be good on the tyres on long runs and the strategists wanted him to run in free air. By doing two stops you pass cars when they come in for their extra pit stops, not on the race track, so you can run at your pace for more of the time.

Raikkonen’s pace and strategy were spot on and easily enough to move him through the field to second place.

The Finn’s consistent driving in the Lotus once again meant that he was able to maintain performance over long stints on the tyres. Lotus didn’t have any problems with the tyres in Bahrain.

Raikkonen questioned whether he had pitted too early by coming in on Lap 35, having just passed Di Resta, but the team was worried about being undercut by Di Resta stopping before them and then having to repass him on similar age tyres. He might have been a little closer to Vettel at the end by stopping a lap or two later, but Vettel had pace to spare in the final stint anyway.

With his main rivals Alonso out of the picture and Raikkonen two stopping from 8th, Vettel had the race won very early on. He pushed hard in the first three stints of the race and eased off significantly in the fourth and final stint. He was able to measure out his stint lengths evenly and popped in a fastest lap just before the end to show that he could have gone faster.

Di Resta vs Grosjean

Romain Grosjean’s race was interesting. He started 11th, six places behind Paul di Resta, but managed to pass him before the end to take the podium. So how did that work out and could Force India have done anything to get Di Resta the podium?

Grosjean had to stop earlier than planned on Lap 8 as he had a piece of front wing endplate lodged in the entry duct so his engine was overheating and so were the rear brakes. This meant that his stint lengths were lobsided, with a 19 lap second stint, followed by 13 laps and 15 laps in the remaining stints. He also had to pass a number of cars on track, so there was a lot more risk for him, but having been forced into the early stop, he had no choice but to stop three times. The further back on the grid you are, the more traffic there is, but with his car pace and new tyres he was able to come through

The key was that the Lotus gets significantly better performance from its tyres from lap 10 of a stint onwards. Once the rear tyres heat up and the thermal degradation kicks in, the performance clearly drops off on the Force India in comparison with the Lotus and this is where there was nothing that could have been done to prevent losing the podium to Grosjean.

Di Resta did the same strategy as Raikkonen; two stops taking new Hard compound tyres at both of his stops. Could he have beaten Grosjean with the faster three stop strategy?

The answer is no. Grosjean’s advantage was that he did the entire race on new tyres (as Raikkonen did from 11th on the grid last year). Di Resta had only two sets of new Hard tyres left after qualifying and no new sets of Mediums. The pace advantage of the Lotus wasn’t the decisive factor in this outcome, it was the two new sets of tyres that swung it. Look at the plot below with Grosjean in black and Di Resta in yellow. The lap times are fuel adjusted and the lower the line on the plot, the faster the lap time. Di Resta’s times are fairly consistent, where Grosjean’s are all over the place due to traffic, but the underlying pace advantage of the Lotus on new tyres is clear.

Bahrain was one of Lotus‘ most competitive tracks last year and they had the pace to challenge for the win this year. So the fact that Force India competed with them across qualifying and race is a positive sign for the Silverstone-based team.

BAHRAIN TYRE STRATEGIES

M=Medium; H=Hard; N=new; U=Used

Vettel MU HN(10) HN(25) HN (42)
Raikkonen MU HN(16) HN(34)
Grosjean HN HN(16) HN(27) MN (42)
Di Resta MU HN(14) HN(36)
Hamilton MU MU(10) HN(22) HN (38)
Perez MN HN(10) HN(20) HN (39)
Webber MU HN(8) HN(21) HN (37)
Alonso MU HN(7) HU(8) HU (24) HN (39)
Rosberg MU HN(9) HN(20) MU (33) MU (44)
Button MN HN(9) HN(21) HN (34) MU(46)
Maldonado MN HN(10) HN(23) HN (39)
Hulkenberg HN HN(12) MU(26) MN (41)
Sutil MU HN(1) HN(18) MU (42)
Bottas HN HN(13) HN(29) HN (47)
Massa HU HN(10) MN(17) HU (28) MU(36)
Ricciardo MN HN(9) HN(25) HU (41)
Pic MN HN(11) HN(23) HN (35)
Gutierrez HN HN(1) HU(16) MN (33) MN(43)
Bianchi MN HN(9) HN(22) HU (36) MU (48)
Chilton MN HN(10) HN(23) HU (37) MU(46)
Van der Garde MN HN(2) MN(14) HN (24) MU(39) HU (47)