What started as two clearly different strategies resulted in Lewis Hamilton and Nico Rosberg fighting over the same bit of tarmac on the very last lap of the race. How did it get to that point? Adam Cooper takes an in-depth look.

It's inevitable that the collision between Lewis Hamilton and Nico Rosberg on the last lap of the Austrian GP has grabbed everyone's attention, but there was much more than just tangling teammates to what was a thoroughly absorbing race.

The events leading up to the clash make for a fascinating story in themselves, as Nico and Lewis ended up disputing the same piece of tarmac – less than a lap from the finish – having run very different strategies.

Last weekend had echoes of other recent races, and not just the controversy generated by the first lap collision in Barcelona. For the fourth race in a row since that double retirement, one Mercedes won the race while its sister car finished off the podium, the streak having now run seventh, fifth, fifth and fourth.

It’s further proof that when things don't go perfectly for one of the W07s, the opposition is now close enough to take advantage.

Ultra Complicated

Even more pertinent is the fact that as in Monaco and Montreal, the scenes of his other 2016 wins, Hamilton put in a critical stint during which he appeared to perform miracles to get a set of tyres to go the distance – in this case his opening run on the ultrasoft tyres with which he qualified.

Mercedes had faced some serious blistering problems with that compound in Saturday's FP3 session, with the drivers only able to run a handful of laps before events were rather overtaken by Rosberg's suspension failure and crash.

Nevertheless by setting their Q2 times on the ultrasoft the Mercedes drivers were committed to using them for the first stint. After qualifying, I asked Lewis if he had concerns about starting the race with a potentially fragile tyre, especially given that both Ferraris and both Red Bulls had set their Q2 times with the more durable supersoft.

“This morning wasn't good,” he said. “I didn't have many laps on the [ultrasoft] tyre. I was supposed to do 10 laps, and I did a lot less than that. So for sure it's a concern. It's going to be cooler tomorrow, so it may swing to a different result in terms of how the tyres are used.

“But I learned a lot from that. There's a lot of changes that I can do in my driving style to make them last longer. I'll try to apply that tomorrow. But who knows how long the supersoft is going to go? Ultimately my main competitor, which is Nico, is on the same tyre as me. That means we will both be in a similar situation, and I hope I can make them last...”

The necessity to do just that came sharply into focus when he was told on Sunday morning that Plan A for the race was a one-stop strategy, and that ideally he would be going to Lap 23.

Come the race Hamilton's first task was to get a good start, and this time he did, helped by the fact that Nico Hulkenberg got away poorly from second. Out front and with a clear track ahead he was able to pace himself and focus on protecting those tyres and ensuring that he could meet that lap target.

Conditions were cooler and more favourable, but the challenge Lewis faced was emphasised by the fact that Hulkenberg was soon in dire trouble with his ultrasofts, and the Force India man dropped down the order before stopping after just eight laps.

And then just two laps after that Rosberg came in, having worked his way up from his sixth starting position to third behind Hamilton and Vettel. Lewis, in contrast, stayed out and kept on going – for another 11 laps in fact, as he finally came in on Lap 21, just two shy of the pre-race target.

So why the early stop for Rosberg?

“Nico's tyres were going, so we had to immediately commit to two stops,” Paddy Lowe told Motorsport.com.

“And we were watching Lewis all the way, and he was still gapping people, so we were leaving him out, and keeping options open, one or two stops. We were also wanting to make sure we covered Ferrari, who looked like they were going one stop. As it turned out we were able to leave Lewis out until Lap 21, which was a good one-stop stop.”

Intriguingly, when I asked Nico if he'd struggled with the tyres in that stint – perhaps because he was in traffic and racing people whereas Lewis had clean air – he denied that there was any issue.

“I had 70 per cent rubber left, I could have gone a very long way,” he said. “So there's no difference there. It was just strategy decision to stay ahead of everybody else, and we planned to go for the two-stop.”

Whatever the real story was with Rosberg tyres there's no question that Hamilton again did an awesome job. Even allowing for cooler conditions reaching 21 laps at a winning pace, having managed fewer than a handful in FP3, was no mean feat. As he had suggested on Saturday, he did his homework, and adjusted his style.

“There are different driving styles you can use to nurture and take care and use and abuse these tyres,” he said after the race. “And in practice I killed the tyres, trying a certain way. But I studied a lot last night, my lines and where I need to do the lift and coast, and where I need to look after the tyres. And I also did that today, this morning.

“It seemed to work well. Plan A, which I was on, Lap 23 and then to the end, [when they told me] I was like I will never get to 23, because the other day I only did four laps. But being cool for sure meant I could get further. But yeah, I was really happy with how I looked after tyres. It's not a surprise, I've done it in other races...”

“He did a great job,” added Lowe. “A combination of that [homework] and the cooler conditions, he was able to keep the tyre in good shape. Conversely that didn't seem to be the case with Nico, I don't know why.”

The Strategy Split

When Lewis made that first pitstop he came out just behind Rosberg, with both men now on softs. It may have looked as though he had lost out, but at that stage the team's intention was that only Nico would have to pit again, and that Lewis would run to the flag. As far as the team was concerned, he had the best strategy – the winning strategy.

“Lewis was ahead on the road, and the one-stop seemed to be the better strategy for the leader,” said Toto Wolff.

“We weren't sure how far Ferrari would go, and whether they would try a one-stop, which clearly they did. Maybe they stretched it a bit too far with Sebastian, or for sure they did.

“So we kept him out there. His times were competitive in comparison with the two Ferraris which were behind him, and we didn't care so much about Nico and the Red Bulls, because they were on a two-stop.”

However, these things can be fluid. After the Safety Car period, and with Vettel now out of the picture, the team's calculations called for a change of plan.

“By the time we had got through the Safety Car and seen all the different paces it was clear that Nico's two-stop was actually going to beat Lewis anyway,” said Lowe. “So even though Lewis was behind and able to do a one-stop, his best race had turned into a two-stop, and he had to compete with Nico head-to-head.

“The difference between the one and two stop was not clear at the start of the race. Obviously you always want to give the best strategy to the lead driver.”

“At the certain stage we changed opinion and we felt the two-stop was a safer way to finish the race,” added Wolff. “And this is why we converted to a two-stop which obviously brought Lewis into a situation which put him behind Nico.”

Slow start to Hammer Time

Lewis was just one second behind when he came in for his second stop on Lap 54. He was told it was 'Hammer Time’, and he had a genuine chance to get ahead of Nico. But it was a sluggish stop, and he had a scrappy out-lap that saw him run wide – he was on the softs, which take a while to warm up, so he paid the price.

Crucial tenths were wasted, and when Rosberg came in just a lap later he emerged from the pits still safely in front, and Hamilton's chance to seize the lead was gone.

Instead we now had 26 laps to the flag, and if Lewis was going to win, he would have to do his passing on track.
Lewis had of course been under the impression for most of the race that he wouldn't have to make a second stop, and as he sat behind Rosberg he could be forgiven for being a little confused about how the race had unfolded.

“I was a little bit not understanding exactly why I was in that position,” he admitted. “I did everything they asked me to do, and then I was pitting again, going to Plan B when we were on different strategies. He was on the two-stop, they had even told me from the beginning, 'Nico's on a two-stop,' so I knew that he would have to stop again. My tyres were great, and then I reverted to a two-stop, which meant I was most likely destined to come out behind.

“I didn't quite understand it, and I still don't, I am sure they will explain it to me later. For me I just had to kind of let it go over my head, and think okay I've got a race, I've got to dig as deep as I can and try to overtake this guy if it takes every breath and beat that's in my heart, I'm going to give everything I can, and then at least at the end I know that I have done everything...”

One intriguing aspect to that final stint was that the two drivers emerged from the pits on different compounds. As noted Lewis had the soft, but Nico had supersofts, and the World Champion sounded a little perturbed on the radio when he asked about the different choices.

In fact he had the better choice, as Lowe confirmed: “The soft was a better tyre, but we didn't have a set of softs for Nico.”

That may seem odd, but there's a simple explanation. Mercedes routinely pre-orders one example of the hardest tyre for one driver, and two for the other. Whoever has a second set runs them on Friday, and that chore alternates between Hamilton and Rosberg.

This week it was the turn of Lewis, but because of the rain on Friday, he did barely a lap on them instead of a full run – so instead of binning them he could keep them for the race.

“Lewis had the advantage this weekend in having an extra soft compared to me which you would normally use in free practice,” Rosberg confirmed. “But because of the rain he was able to carry it on to the race, so that was always going to be a big advantage for him today, which I was well aware of. And that is one of the main reasons he was given an opportunity in the end, but I fully accept it was a fair approach from the team. It was just lucky circumstances that he had the extra soft.”

Meanwhile Nico had a set of new supersofts left – because he didn't run at the end of FP3 after his crash – while Lewis didn't, so it was logical that he used those.

That split of compounds, soft for Lewis and supersoft for Nico, added an extra dimension to that final run to the flag. Both men also had to work their way past Max Verstappen, who was one-stopping and got ahead when the Mercs pitted, but obviously didn't have the pace on his old tyres with which to stay in front.

Lewis took two laps longer to get by, and lapped traffic also played a role as the gap ebbed and flowed.

As the laps ticked down, Rosberg had his hands full, with Lewis in his mirrors, while knowing there was potentially less life in his tyres. And then right at the end he hit brake problems.

“He had very high brake wear,” said Lowe. “And we were within the limits of the regulations trying to tell him how to manage them. But on that last lap his brakes failed out to what we call passive mode, so the brake-by-wire wasn't working any more – the brake-by-wire on the rear circuits becomes inactive. You lose some strength in the brakes, and some of your energy recovery.”

Lewis had regularly been in DRS range in those closing laps, but it was only when Nico got the first corner a little wrong at the start of the last lap – clipping the inside kerb – that Hamilton found the momentum to make that charge up the outside into Turn 2, and stuck his nose in front.

And what happened next is another story...

Source: Motorsport.com

Gallery: Analysis: How Hamilton vs Rosberg became an on-track battle