Pirelli has admitted that a single stop for tyres was the only way to go in the Monaco Grand Prix, even if it limited chances to shake up the order more than usual on the tight street circuit.
The Italian company took its soft and supersoft tyres to the Principality to maximise grip levels on streets that are open to the public, even over the race weekend, but teams were denied the chance to learn more about them when it rained during Thursday afternoon's practice session. With Saturday morning then dedicated to catching up on other information sources, many teams went into the race uncertain of their performance on the softest rubber, or of its longevity under heavier fuel loads.
Only five drivers started the race on the soft compound, with the exception of ninth-placed Sebastian Vettel all of them coming from outside the top ten, as the leading runners used the supersoft to set their times. The threat of rain coinciding with the expected time of the first stops then forced teams into running longer than expected on the softer rubber and, when it proved more durable than expected, race strategies began to alter.
Mercedes driver Nico Rosberg was the first of the leaders to change from supersoft to soft on lap 27, banking on no rain coming, and, two laps later, race leader Mark Webber also pitted, crucially emerging still ahead of Rosberg. The longest stint on the supersoft was carried out by Toro Rosso's Daniel Ricciardo, who made his original set of P Zero Reds last for 40 laps.
Vettel's strategy meant that he was able to take the lead by the halfway point of the race, building up a significant advantage by the time he finally pitted for supersoft tyres on lap 46, having put in a series of rapid laps. But it was not quite enough for him to keep the lead after his stop, and the German re-joined in fourth position behind Fernando Alonso.
"Once again, we saw that the cars were all extremely closely-matched, equalling each other on pace throughout the race," Pirelli motorsport director Paul Hembery commented, "This was despite the fact that nobody had any proper running on the supersoft with full tanks, due to the mixed weather conditions during free practice on Thursday. As a result, calculating the strategy was extremely complicated.
"But, with the nature of the circuit, plus a tyre choice that was certainly more conservative, and hardly any tyre degradation, it was clear that a one-stop strategy was the way forward as soon as the teams learned more about the performance of the supersoft after the race got underway. Obviously, that led to longer stints and limited opportunities for overtaking. Although there was some rain at the end, our slick tyres still offered enough grip to carry the leaders through to a very close finish with the top six finishing within six seconds of each other.”
Toro Rosso driver Jean-Eric Vergne was the only one to gamble with the late-race rain, but also used strategy, with an early pit-stop on lap 17, to move from 17th on the grid to a points-scoring seventh. His gamble, switching to intermediates with six laps to go, after running on the soft tyre for 53 laps, did not pay off, however, and he was left to rue what might have been as the downpour only arrived after the chequered flag.
As always, the timing of the pit stops was crucial in Monaco, particularly in order to ensure that cars did not feed out into traffic that is difficult to overtake. A flawless one-stop strategy from Red Bull ensured that Webber was able to convert his pole position into a second win at Monaco.
“Congratulations to Mark Webber and Red Bull," Hembery concluded, "The team managed their race and their tyre strategy perfectly, winning Monaco for the third year in a row and a race for the second time this year."