Probability management in Formula 1
Posted on May 30, 2014
By James Allen
When Sauber’s Adrian Sutil crashed heavily on Lap 24 of the recent FORMULA 1 GRAND PRIX DE MONACO 2014, the F1 teams’ strategists were on red alert. The question all were asking themselves was – “Will there be a Safety Car?”
This is what strategists call, “Probability Management”. They quickly assess the damage to the accident car, look for debris on the track and work out the probability that the FIA Race Director will deploy a Safety Car.
If a driver can get into the pits first, while the rest of the field is touring round at the mandatory reduced speed behind a Safety Car which equals 140% of the normal lap time, there is a chance he might gain some places.
Why is this significant at Monaco? Because it is extremely hard to overtake on the circuit and so, apart from cars dropping out ahead of you, the only way to make up places is through taking some chances on pit strategy and particularly when there is a Safety Car.
Statistically the chance of a Safety Car this year at Monaco was 80%, one of the highest probabilities of any circuit. The Race Director did deploy a Safety Car because of the debris.
The first car to pit, unsurprisingly, was Jenson Button. The McLaren team has done a lot of work on probability management and always briefs its drivers that there is a "Safety Car window", where they can pit at their discretion if they see an accident or "SC" boards, before the team see it and if they are in a late phase of the lap. In this situation a driver can radio the team that he is coming in so they can get a new set of tyres ready for him.
If a Safety Car is subsequently deployed, this tactic works sometimes, as it did for Button in Australia earlier this year. It works when someone you are racing against does something wrong or unusual; for example, in Australia Button gained two places with this trick because Fernando Alonso slowed behind the Safety Car and stacked up the cars behind him, including his own team mate Kimi Räikkönen.
Button didn't gain any places in Monaco, because everyone went at the correct speed once the "Safety Car Deployed" signs went out.
But it can often bring a gain and Lewis Hamilton remembered painfully that he had lost two places in Monaco the previous year, to Sebastian Vettel and Mark Webber, in precisely this way.
So Lewis felt it was worth a try this year, as a way to get ahead of his team mate. Mercedes’ strategists meanwhile disagreed.
For a start, Mercedes run a clear policy of the leading driver having a stop preference in races and in this case, the leading car was Hamilton’s team mate Nico Rosberg.
Also Mercedes had a comfortable 1-2 lead with a margin of 12 seconds over the third car, Kimi Räikkönen.
Mercedes’ probability management went like this: there was no guarantee a Safety Car would be deployed, as later accidents like that of Esteban Gutierrez proved.
Mercedes assessed that it was 90% likely that a Safety Car would be used, but more importantly, as leaders by 12 seconds, there was 0% risk to Mercedes of losing positions by doing an extra lap and waiting to see if a Safety Car was deployed. Because with all the cars obliged to run at a set Safety Car speed, there was no way they could lose 12 seconds to Räikkönen.
However, if Hamilton had pitted, like Button, and there had been no Safety Car he would have been behind both Ferraris and could have been vulnerable to Ferrari deliberately leaving one of their cars out to block him while the other built a gap. Given that the "blocking" car would be Alonso, this is unlikely, but with a possible second place on offer for Ferrari, you never know.
Mercedes has a single head of strategy on site and his job is to deliver a Mercedes 1-2 finish, which he did, even if Hamilton was frustrated.