Indian Grand Prix: Strategy Predictions

Posted on October 26, 2011


With the Indian Grand Prix being a new race, we are dependent upon the simulation data from the teams to have any idea of how the race might play out. Pirelli are bringing the soft and hard tyres, but in a break with tradition it is the softer tyres which are being designated the prime tyres. At the previous race in which this tyre combination was used, the difference between the tyres was of the order of 2 seconds. This might not be the case here, but the expectation is that the option tyres will be significantly slower than the primes.

With little data to go on, I have cast around, and it seems that the fuel penalty will be similar to that at Suzuka and the surface is smooth, but green. Therefore it is not clear how far the tyres will go, but come Sunday, they may last well – intelligentF1 will make an assessment of the Friday practice to see if there are any indications on the tyre life. The pitstop loss time appears to be reasonably average, at around 20s it is again similar to Suzuka.

So, let’s consider two scenarios. Firstly that the options are 2s slower than the prime tyres, and secondly that the time difference is only one second. With a 2s difference, the prediction of the race history looks like this:

The difference between a 2 stop race (which needs the soft tyres to last 26 laps) and the 3 stop race (20 lap tyre life to be optimal) is about three seconds. Therefore, as there is more flexibility in the three-stopper, this must be the favourite option. A one stop strategy is 30s slower. If the time difference is genuinely two seconds, and the tyres last, the optimum three-stop strategy is to do one lap on the hard option tyres. This is not particularly good for the racing, so it is my hope that the hard tyres are more competitive, although it does open the intriguing option of teams starting on the hard tyres and hoping to change with an early safety car.

If the hard tyres are within 1s of the soft tyres on pace, then the picture looks like this:

The main difference here is that the one stop strategy becomes more competitive, now being only 15s off the pace. Therefore a long stint on the hard tyres looking towards a one stop race is only likely if the hard tyres are less than 1s slower than the softs. This is not out of the question for teams which tend to perform better on the hard tyres – the good relative performance on the harder tyres is the main reason that Sauber are able to be competitive on a smaller number of stops than (most of) the other teams. The optimum one stop strategy needs 35 laps from the softer tyre in this case.

Again two and three stops are closely matched, the difference being only two seconds. This time the required tyre life is 23 laps for a two stop and 17 laps for a three stop, but at least in this case we get a reasonably sensible final stint length. The expectation would be that the quick teams would tend towards three stops and the midfield towards two – if the tyres last.

So in summary, it seems (with the limited data available) that the pace difference between the hard and soft tyre is likely to be key to deciding on a strategy – with three stops being the safe way out as it is as competitive as a two stop, but requires less longevity from the soft tyres. The numbers from the intelligentF1 simulations are:

Hard tyre pace deficit 2s:                3 stop optimal;          2 stop +3s;                 1 stop +30s

.                              tyre life needed-   20 laps                          26 laps                         40 laps

Hard tyre pace deficit 1s:                2 stop optimal;          3 stop +2s;                 1 stop +15s

.                             tyre life needed-    23 laps                          20 laps                         35 laps