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Analysis: Could Hamilton have won F1 Abu Dhabi GP with a different tyre decision?

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Analysis: Could Hamilton have won F1 Abu Dhabi GP with a different tyre decision?
Dec 1, 2015, 4:04 PM

The Formula 1 season finale lacked drama and tension, as the title was decided last month, but it provided a very interesting talking point from a ...

The Formula 1 season finale lacked drama and tension, as the title was decided last month, but it provided a very interesting talking point from a race strategy point of view. Once again, Lewis Hamilton came up short in both qualifying and the race and his strategy in the final third of the race was the subject of much debate.

Could he have won this race if Mercedes had played it differently and either put him on the faster tyre, or pitted him a few laps earlier?

We will analyse that and answer the question many fans are asking about how you time a pit stop to ensure that the gap to the car you are chasing is bridgeable on your new tyres.

There were some great cameos in the race from other drivers, like Romain Grosjean who went from 18th to 9th on a reverse strategy and Sebastian Vettel who did the same and moved from 15th to 4th.

XPB.cc Nico Rosberg

Pre Race Expectations

Very stable conditions as always at Yas Marina led to ideal practice running for all teams. Friday practice showed that the Ferrari of Kimi Raikkonen was very fast on both tyres, especially the soft, while the Force India looked like it would struggle with tyre life compared to the Red Bull. As Perez outqualified Ricciardo that was set to be a fascinating strategy battle.

All strategists were briefing that it would be a two stop race with cars at the front running supersoft/soft/soft and fast cars coming through from the back doing the opposite: soft/soft/supersoft.

As most of the championship battles were already resolved, there was a sense that everyone would ‘go for it’, with nothing to lose.

Lewis Hamilton

Did Mercedes cost Hamilton the win with final stint strategy?

What marked this Abu Dhabi Grand Prix out from other races in the Nico Rosberg, Lewis Hamilton era was that Mercedes gave Hamilton quite a bit of autonomy in his strategy choices in the final part of the race.

Hamilton lost out again to Rosberg in qualifying, for the sixth race in succession and lost out at the start, meaning that Rosberg had the first call on strategy and pit stops.

As usual, the deal was that if Hamilton had the pace, Mercedes would give him a strategy to challenge his team mate at the end. What made it interesting here was they put the ball in his court and let him and his engineer decide what tyre to use for the final stint and when.

There was no question of doing three stops, as this was a slower strategy than two. Hamilton raised the question of staying out on the second set of softs, making it a one-stop (something he had proposed in Austin).

That would have required a 44 lap stint on softs, which no-one had come close to managing all weekend and his tyres would have been over 4 seconds a lap slower in the final stages, if indeed they lasted that long. To be fair to Hamilton, he did not have that data in front of him, but his engineer knew the numbers and declined that route.

Once Rosberg pitted for his second set of new softs on Lap 31, it was up to Hamilton how to react to try to win the race. He had been just 1.3secs behind when the German stopped.

One option was to extend the stint and then fit super softs at the end for a 12-15 lap sprint. Another was to extend the middle stint long enough to create an offset on the soft and then use the newer tyre performance to catch and pass Rosberg on old softs.

This is all about plotting old tyres versus new and measuring the gaps. To help fans to fully understand how this works, we have generated this graphic, with the help of our JA on F1 technical adviser Dom Harlow, ex Force India chief engineer. It shows the linear degradation of the tyres, with the tyre age in laps across the horizontal and the drop off in lap time up the vertical axis. [Key: Option = Supersoft; Prime = Soft - Click to Enlarge]

Dominic Harlow

It’s clear that the offset from having tyres that are 10 laps fresher is around 1 second. That means that your car is 1 second per lap faster than the other car whose tyres are 10 laps old. To overtake an similar car at Yas Marina you need a pace offset of 1 second, (allowing also for the DRS effect)

So that was Hamilton’s target. Alternatively he could have pitted two or three laps earlier (7 or 8 laps after Rosberg’s stop) - when the gap he would then have to bridge was around 1.5s smaller – and try to get him earlier in the final stint, but with a more difficult overtake. Had he stopped on Lap 38 for example, he would have come out around six seconds behind Rosberg with 17 laps to the finish and he would have caught him after about nine laps, but would have had only a 7/10ths of a second speed advantage to try the overtake.

What appears to have happened to delay Hamilton’s second stop is that the sector times looked reasonable in Sectors 1 and 2, but then on some laps, Sector 3 wasn’t so strong, making it tough to pick the precise moment to pit for tyres

After much deliberation, Hamilton’s engineer Peter Bonnington took the decision in the end, to stick with the soft tyre, rather than the supersoft.

Podium Abu Dhabi 2015

This was done because the evidence of the first stint was that the tyre grained and performance went off after about five laps, so it would not have given Hamilton enough when he would need it to make the pass at the end of the stint. This is borne out by the experience of Sebastian Vettel on the supersoft in the final stint (see Race History Chart below, where the gradient of the red line flattens out as the performance drops)

The computer models show that the gap was bridgeable after he stopped on lap 41 at 12.5 seconds, with 14 laps to go and on tyres that were 1 second per lap faster, but after a strong start; he suddenly started getting variability in the lap times. He wasn’t able to maintain the charge and it stayed at around 7 secs from Lap 47 to the finish. It has to be said that Rosberg responded very well in what was probably one of his best drives in F1.

The mistake was probably in leaving it 10 laps, rather than 8, as he probably overdid it on the tyres.

He was also using engine modes which clearly the team did not want him to use, as he was told several times to revert to a lower mode. The team explained afterwards, that both drivers have to be in the same mode, otherwise it is unfair. This is a legacy of issues around turning up engine modes in Bahrain and Spain last season. An accord was put into place as a result, which it appears Hamilton tried to override in the final 14 laps in Abu Dhabi.

XPB.cc

Force India team game helps Perez to finish on a high

The best of the rest behind the Mercedes and Ferrari cars in Abu Dhabi was not a Williams or a Red Bull; it was Force India, underlining what a strong end to the season the team has had.

After qualifying fourth with a stunning lap, ahead of Daniel Ricciardo, Perez knew that it would be hard to keep the Red Bull driver behind him as the Force India was harder on its tyres.

However the intervention of Perez’ team mate Nico Hulkenberg at the start swung the balance.

From 7th on the grid, Hulkenberg managed to get ahead of Ricciardo on the opening lap, which gave Perez a buffer that the strategists could work with.

On paper the Red Bull was a faster race car, but Hulkenberg's intervention protected Perez from an early undercut from Ricciardo at the first round of pit stops and, although Ricciardo cleared the German at those first stops, Perez already had a cushion. Some smart strategy from there by Force India set the Mexican up for a superb fifth place finish behind the Mercedes and Ferrari cars, even though Ricciardo caught him at the end, it was too late. It meant another 10 points to add to the 68 Perez had already scored this year. A haul of 78 points makes it his best year in F1.

The UBS Race Strategy Report is written by James Allen with input and data from several of the leading teams’ strategists, from Pirelli and from JA on F1 technical adviser Dominic Harlow

Race History Chart - courtesy of Williams Martini Racing - Click to enlarge

Look at Vettel's pace drop off on the Supersoft after around seven laps of his final stint. This is what would probably have happened to Hamilton had he chosen that tyre for the final stint. In contrast, compare it to the soft tyre on Raikkonen’s car, which had much less degradation. If you look at the final few laps of Hamilton’s first stint on used supersofts, the performance is not there after around 8 laps of racing.

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Series Formula 1
Drivers Lewis Hamilton Shop Now
Tags race-strategy-calculator