How the Canadian Grand Prix got away from Alonso and Vettel

The Canadian Grand Prix was always set to be a close finish because of the nature of the track, the options for race strategy and the effectiveness of the DRS rear wing for overtaking.

And the data shows that the performance of the McLaren, Red Bull and Ferrari on race day was remarkably close, perhaps only a tenth or two of a second in it. The difference was tyre management and, more importantly, strategy.

Post race, Red Bull and Ferrari have been accused of making strategy errors which cost the race, but is it true?

Here is our customary in depth analysis of how - and why - the big decisions got taken, with input and data from some of the decision makers.

The race had three leaders, any one of whom could have won: pole sitter Sebastian Vettel finished fourth, Fernando Alonso led with seven laps to go and finished 5th, while Lewis Hamilton was the only driver to make a 2 stop strategy really work and he won.

Background

The danger with doing one stop in Montreal is that, although you are in front of a two stopper when he comes out from his second stop, he's on fresh tyres and with the DRS wing he will find it easy to pass you. However with a 71% chance of a safety car, which would swing the race to the one stoppers, it can be worth a gamble for midfield runners looking to make up places.

To gamble from the front row of the grid, however is a different matter.

Practice on Friday had shown the teams that the tyre degradation was not a problem and that it would be possible to do one stop effectively, even if it would mean a fair amount of nursing the tyres. However McLaren were convinced that they needed to do two stops, so it would be an attacking race for Lewis Hamilton. They believed that a two stop would be around 10 seconds faster than a one stop.

McLaren only really had one car running on Friday, as Jenson Button lost most of the day to an and oil leak and double gearbox change. Meanwhile Ferrari didn't really do any long running, the longest run was a 12 lap stint by Massa, but this was punctuated by slow laps. And this may well have contributed to what happened on Sunday.

But the track temperature on race day was 15 degrees hotter than Friday and going into the race even teams who had plenty of data on the long run performance of the tyres could not be sure that one stop would turn out better. The only way to find out would be to try it and to monitor the heat degradation, because when it comes in with these Pirelli tyres it is very sudden and the lap times drop off straight away.

The rear tyres were the limitation, and the soft tyre looked like the preferred race tyre.

How the race got away from Alonso and Vettel and went towards Hamilton

The leaders got away in grid order with Vettel leading Hamilton and Alonso. But at the first round of stops, where they all switched from used supersofts to new softs the order changed: Vettel pitted first on lap 16, Hamilton on lap 17 and Alonso on lap 19. Hamilton jumped Vettel in the stops and Alonso jumped both of them. But it took Alonso's Ferrari time to warm up the tyres and Hamilton attacked and repassed him for the lead.

So for the second stint the order was Hamilton, Alonso, Vettel. At this point all three had the option to stop again.

Only Hamilton knew for sure that he would be doing that and so, with clear air ahead of him, he kept pushing. He opened out a gap of four seconds on Alonso and maintained it. For Alonso and Vettel the problem was not knowing how hard to push, as they didn't want to find themselves one stopping and have the tyres go off at the end, but equally they didn't want to do too little and find at the end that the tyres still had plenty to offer.

Decision time

Hamilton noticed that the other two were not staying with him and asked his team if they were certain that Alonso and Vettel were not one-stopping. The team reassured him. This confirmed to Red Bull and Ferrari that Hamilton was stopping again and they will have recalculated their race model based on this information. It will have shown them ahead of him after his second stop, but the unknown was still the tyre degradation on this warm day.

In the laps leading up to Hamilton's stop, Alonso's pace was consistent; in the high 1m 17s and low 1m 18s. Vettel's was a few tenths slower and he sat 3 seconds behind Alonso.

When Hamilton pitted on lap 50 Ferrari and Red Bull had a decision to make. Should they react and pit too? In Vettel's case he would not have got ahead of Hamilton by doing that, but he may have got Alonso.

Ferrari's decision was more finely balanced. As he came down the back straight, Alonso had a lead of 14.8 seconds over Hamilton, about the time it takes to make a four second pitstop. With Ferrari's strong pit stop performance there was every reason to believe that Alonso would be at least side by side with Hamilton as he exited the pits, but more likely just ahead. However they knew from the first stops that Hamilton might be able to pass them again as they struggled to warm the tyres.

But they were concerned about Vettel too. So they did not pit Alonso on lap 51. But they had perhaps also taken their eye off the other cars coming through from behind, especially Grosjean.

At this stage Alonso could have pitted and rejoined ahead of Grosjean, consolidating his position. However they had some time to reflect, because even if they were to pit and come out behind Grosjean, the Ferrari on fresh tyres and with DRS would have no problem passing the Lotus on worn tyres.

The longer they and Red Bull left it, the more other cars came into the picture, like Perez, who's signature strategy seems to be to get to the flag quickly on one stop. So even a delayed pitstop in the laps after Hamilton's would still have given both Alonso and Vettel a podium, but they didn't do that either.

This is one of those situations where it is easy to say with hindsight that they made a mistake. Ferrari argues that they thought they would get similar tyre performance to Lotus and Sauber and make a one stop work.

However what puzzles rival strategists is that by the decisive moment around lap 51/52, the other Ferrari driver Felipe Massa's tyres were 40 laps old and already showing signs of going off. Perhaps Ferrari estimated that Alonso would have better wear, but they were looking to get 51 laps out of Alonso's tyres, ten more than Massa had done to that point.

So it's hard to see where their confidence to stick with one stop came from.

Even as late as lap 60, when Grosjean was just 10 seconds behind Alonso, the models showed that Ferrari could have pitted Alonso, who would have rejoined 5 seconds behind the Frenchman and on fresh tyres Alonso would have been able to pass him in the 10 remaining laps, as Vettel did with Alonso when Red Bull realised their mistake and belatedly brought Vettel in with seven laps to go.

Lessons from Canada

Grosjean's result shows that the Lotus has the potential at times to do one stop less than some of its rivals and still be competitive. It's weakness lies in single lap qualifying pace; if Grosjean or Raikkonen could start in the front five, ahead of Rosberg for example, then they could really make their tyre advantage pay.

Perez' excellent podium again highlights his ability to keep the pace up while also protecting the tyres. It must be a combination of many details in his driving, that he has brought with him into F1, because Kobayashi in the other car can rarely stretch the tyres out in the same way.

Perhaps more worryingly, this was the second race which could be done by cruising around on a one stop strategy and although the climax was exciting due to Hamilton's strategy, the majority of the race was quite dull and processional.

These cars and tyres work best in two or three stop races, where the drivers are able to have periods when they can push more.

The UBS Race Strategy Report is written by James Allen with input and data from several F1 team strategists and from Pirelli

Tyre Choices, Canadian GP

SS= Supersoft; S= Soft: N= New; U= Used, DT= Drive through penalty; (17) = Pit Stop lap

Hamilton SSU SN(17) SN(50)

Grosjean SSU SU(21)

Perez SN SSN(41)

Vettel SSU SN(16) SSU(63)

Alonso SSU SU(19)

Rosberg SSU SN(19) SU(38)

Webber SSU SN(17) SN(52)

Raikkonen SN SSU(40)

Kobayashi SSN SN(24) SN(25)

Massa SSU SN(12) SSU(58)

Di Resta SSU SN(13) SN(44)

Hulkenberg SN SSN(21) SN(42)

Maldonado SN SSN(29)

Ricciardo SSU SN(17) SSN (58)

Vergne SSN SN(16) SN (43) DT (47)

Button SU SSU(15) SSU(33) SN(52)

Senna SSU SN(23)

Kovalainen SS SN(17) SN(42)

Petrov SSN SN (18) SN(43)

Pic SSN SN (28)

RACE HISTORY, Supplied by Williams F1 Team