Rosberg needs to do this when it counts

This was the drive of a champion. Well, not quite, because the man who won the Mexican Grand Prix cannot now finish the 2015 Formula 1 season as champion, but it was a performance worthy of the accolade.

The big question is whether Nico Rosberg can make a habit of what he produced on F1's return to the Autodromo Hermanos Rodriguez for the first time in 23 years, and use his victorious display as a platform on which to build a title tilt in 2016.

In all honesty, Rosberg has not given Lewis Hamilton much to worry about this season. Such has been Hamilton's superiority that he was able to clinch his third world title with three races to spare.

True, Rosberg has suffered two unfortunate car failures over the second half of this year, but even if you credit back the 25 points he lost for a likely victory in Russia, and the 15 he would have scored for third before his engine blew in Italy, Hamilton still would have led the championship by 33 points with 75 to play for coming into the weekend...

Of course, Hamilton could point to 12 points he likely lost when his engine's turbo pipe worked loose in Singapore, but even with 100 per cent reliability on both cars we'd simply be seeing a prolonging of the inevitable.

The two Mercedes lead through the stadium on lap one © LAT

Since winning September's Japanese GP, Hamilton only needed to finish second to Rosberg in every subsequent race to be assured of the championship. This is Hamilton's season; Rosberg just hasn't been good enough.

But if he can reproduce the form he showed in Mexico more regularly then he will be good enough. This was arguably Rosberg's most complete display of the season, staying one step ahead of his Mercedes team-mate through qualifying and converting pole position into victory with a flawless drive in the race.

Well, flawless apart from the brief 'off' he had at the esses late-on, which ultimately cost him nothing on a day when circuit conditions caught out almost everyone. No question, this was Rosberg at his best. The qualifying tide has turned a little already recently (this was Rosberg's fourth straight pole start), but having been outmanoeuvred by Hamilton after inconsistent getaways recently, this time Rosberg nailed it.

"I've been working on it, to try and get everything perfect and today it worked out," said Rosberg, who got a clean launch from pole while Hamilton spun his rear wheels and therefore couldn't take full advantage of an aerodynamic tow from the sister Mercedes on the long run down to Turn 1. "That was important, maybe the most important part of the race."

Thereafter the race was Rosberg's to lose, and he showed no signs of cracking. One wonders if the early climax to this year's championship battle has created a shift in mental balance, whereby Rosberg is able to drive more freely without the pressure of the bigger picture weighing him down, while Hamilton has throttled back slightly, after finally fulfilling his life's ambition.

In actual fact it didn't seem to work out that way. After the first lap, Rosberg was only 0.050 seconds faster per lap than Hamilton on average over the next 24 (before he made his first pitstop) as the duo traded fastest laps.

During the second stint on medium tyres, Hamilton was actually 0.206s faster than Rosberg on average. This wasn't the driving of a newly crowned champion in cruise and collect mode...

Hamilton rues a rare defeat © LAT

"Nico drove really well today, no mistakes, no gust of wind," said Hamilton, referring to the reason Rosberg gave for losing the previous race at Austin.

"It was very difficult to follow [another car] here, but I gave it my all. I was pushing the whole way.

"It was quite fun actually just to be able to push and not have to be worrying about points or anything like that. Just go out and race. That was one of the fun races for me."

So Hamilton was clearly on full-attack, even with the championship settled. In fairness, Rosberg has always been a driver who's seemed strong at resetting after a setback, treating each race as an individual challenge and not allowing a sequence of negatives to trouble him unduly.

Therefore, the question of using any of these final races to build momentum for next season doesn't hold any water for him, despite the fact this was probably his most convincing victory yet over Hamilton.

"I don't think about it that way," he said. "For me, I'm just thinking about the races.

"It's awesome to win here and that was my target, there was no [thought of] P2 in the championship or getting one back on Lewis or whatever, none of that, it was just 'go out there and win' and the same thing for the next two.

Mercedes victory photo line-ups have usually been the other way round © LAT

"I'm not thinking about 2016 yet majorly. Of course there's bits and pieces that you need to plan ahead and already count for next year, but I don't think of these trends or things like that.

"For me, this weekend was [about] the weekend; pole position was the best chance to win and get the job done and that's it. I did manage to put the past away and move forward."

But perhaps one element of the past has been crucial here. Mercedes called a meeting between its drivers ahead of this race, following the contact between the two at the first corner at Austin. Hamilton and Rosberg both consistently refused to comment on that meeting, or relations between them afterwards, but outwardly things looked frosty to say the least.

When world championships are at stake, friendships - even cordial working relationships - surely count for very little. Perhaps now, Rosberg sees clearly that he must put himself first at all costs if he truly wants to conquer the world.

Continuing to take each race step-by-step, focusing on the individual moves that make a race weekend come together, and avoiding the distraction of what's happening on the other side of the garage, will be key if he is to make what happened in Mexico a more regular occurrence.

But whatever Rosberg's state of mind coming into this weekend, Mercedes certainly felt the timing of this victory was vital, coming so soon after he'd thrown the race away at Austin with that oversteer moment at Turn 16 while leading.

"I felt sorry for him because I know how it feels when you get blown off all the time," said the team's non-executive chairman Niki Lauda, who knows what it takes to win a world championship, or three.

Lauda was pleased to see Rosberg back on form © LAT

"The worst thing is when you screw a race up and the other guy is champion. This is the worst thing that can happen to a racing driver.

"Therefore it's good that this race was the other way around, so he [Rosberg] gets his stability back, and he will keep on fighting.

"Psychologically it's the best you can do after the weekend he had before. You cannot do a plan for recovery. You have pole position, you win the race, and Hamilton is second. Then you are fully recovered. This is all it takes.

"For me the most important thing is these two guys push each other, and if one does not push as much anymore the other doesn't go as quick. This calibration is back, which is good for the drivers and good for us."

Whether Rosberg can translate the form he showed here to the majority of circuits on the calendar will also depend on technical aspects, as much as his mental fortitude.

The revised and resurfaced Mexico City track was naturally slippery, with grip levels changing dramatically from session to session.

Rosberg has generally been strong in circumstances where the circuit has been inconsistent, such as Silverstone this year when he was faster than Hamilton on slicks as rain began to fall.

Rosberg was literally on fire on Friday when his brakes overheated, and metaphorically so in the race © XPB

The new surface also behaved similarly to Sochi in terms of its interaction with the tyres, which meant less concern over rear tyre degradation and more about wear. Rosberg was faster than Hamilton in Russia, and was a step ahead on the resurfaced Interlagos circuit at last year's Brazilian GP.

Perhaps there is something about new and smooth surfaces that favours Rosberg, or nullifies an advantage of feel that Hamilton holds at other places?

Whatever the specific reasons, Rosberg held the edge here, and Hamilton's only real chance to steal victory came when Mercedes decided to switch to a two-stop strategy.

Rosberg pitted for a fresh set of mediums on lap 46, conceding his lead to Hamilton. Mercedes mechanics readied themselves in the pitlane to receive Hamilton a lap later, but he stayed out, questioning whether it was really necessary to make another stop.

"This wasn't a simple race," explained Mercedes technical chief Paddy Lowe. "We went into it with lots of unknowns, and plenty of parts of the car right on the limit, especially in terms of brake cooling.

"We had to manage the temperatures throughout to ensure that they stayed within limits, and we didn't get into a situation of runaway brake wear.

Hamilton hinted at trying to spring a tyre surprise © LAT

"Tyre behaviour was also an unknown, and after the first stint, it was clear that the wear levels were higher than we predicted on Friday.

"After completing the first stint, we had no rubber left on one of Lewis's tyres, and a much longer stint to complete on the prime.

"With a clear pitstop gap to the cars behind, we therefore switched to a two-stop strategy because the planned stint length on the prime tyre would have been too marginal for comfort."

Hamilton eventually accepted this argument and made his own second stop on lap 48 (a lap later than scheduled), but insisting that his team "check those tyres and let me know", clearly feeling the stop was unnecessary.

The fact Mexican home hero Sergio Perez was able to complete the race without trouble having done 53 laps on his sole set of mediums suggests Hamilton had a point...

One wonders if he would have ignored the team and stayed out had the title still been on the line, but as it was this became academic when Hamilton decided to obey Mercedes' call to stop.

A bad day for Mercedes' nearest rivals created the conditions for this strategy switch. Red Bull was not as quick on Saturday or Sunday as it looked on Friday when the track was its most gripless, while Ferrari suffered its first double retirement since the 2006 Australian GP thanks to both drivers crashing out in separate incidents.

Ferrari was in no position to interfere in the lead fight © XPB

Hamilton was again marginally faster (by about 0.008s per lap on average) over the final stint on the medium tyres, but could make no significant inroads. In fact, he ran off the road at Turn 12 before Rosberg had his own moment at the esses. Whichever way you sliced it, this was undoubtedly Rosberg's day.

"I just had all the puzzle [pieces] fall into place this weekend and at previous ones there was one that didn't fall into place," he said.

"That's it; that was the only difference - the whole weekend just went really well. From the first lap onwards I just felt comfortable, got the set-up right - we had all of that; a great job from the engineers, pole of course, got into Turn 1 first, all of those things count."

Rosberg talks of the continually evolving battle between himself and Hamilton, as each seeks to self-improve and out-do the other. Perhaps Rosberg has just been a little slower on the uptake this season - taking several races longer to work out the key nuances of the W06 than his team-mate.

Whatever, during the last two races Rosberg has displayed everything he needs to be a champion: pure speed, aggression, confidence in battle, the capacity to stay calm and bounce back from adversity, and the ability to beat his nearest rival convincingly over the course of a full GP weekend - with no obvious extraneous circumstances falling in his favour.

But it's also true that in each of the last two races he's essentially had nothing to lose. The title battle has been all but over for some time, pretty much for the last three races, which is also pretty much the point at which Rosberg has started driving with greater freedom.

Under these circumstances he's proved he can get the job done, but the true test will come when everything is on the line once again. And that situation won't come around again for a while yet...