Nico Rosberg stopped Lewis Hamilton's momentum with a commanding victory in Spain, but could the Briton have beaten him if he'd been allowed to drive flat-out to the finish? Adam Cooper analyses the Barcelona race.
The Spanish Grand Prix may not have been a thriller, but behind the scenes there was plenty of intrigue going on as Nico Rosberg got his Formula 1 World Championship campaign back on track.
The key element of the race was how Mercedes changed strategies to help Lewis Hamilton get past Sebastian Vettel – and how it then intervened to try to call off the fight with Rosberg.
The radio conversations between Hamilton and the pitwall at the end of the race were fascinating, as the team tried to call off the fight and the man in the cockpit wanted to push.
Were fans robbed of a fascinating fight between the main title contenders, or was that never in prospect?
First moments were key
The start was, of course, key to how things unfolded as Hamilton lost out to Vettel (and almost Valtteri Bottas) on the run to the first corner.
We'll never know what would have happened had Hamilton got away well, and either made it to the first corner safely in second, or perhaps even snuck ahead of his teammate.
In the event he had a poor getaway, and by his own admission was lucky not to be demoted to fourth by Bottas.
As it was he found himself stuck behind Vettel, and as is so often the way at Barcelona, he couldn't find a way past.
The opportunity should have come with an undercut at the first pitstop, but a rare drama for Mercedes with the left rear – a wheel gun issue was cited by Toto Wolff as the cause – led to a disastrous 5.3s stop.
When Vettel responded a lap later, he was gone in 2.3s, and thus emerged still comfortably ahead.
Had he leapfrogged Vettel, Hamilton would have been perhaps 4-5s behind Rosberg with over 50 laps still to go, and in theory just the one pitstop for the both of them.
An impossible task
It would have been fascinating to see how that would have unfolded, given that priority would have been given to Rosberg at the stops. Hamilton would have had to find his own way past.
Instead, he found himself stuck behind Vettel once more.
A fascinating radio conversation followed as his engineer said, “You need to do this on track.”
Hamilton wasted no time in saying, "That's pretty much impossible."
He added that the pit wall had to "come up with another solution."
And that's just what they did...
Switching to three stops
Instead of running Hamilton to around the 40-lap mark on that second set of tyres – new options (mediums), like both Rosberg and Vettel up ahead – the team brought him in for a set of new primes (hards) on lap 32.
In theory he could run to the flag on lap 66 having now used both types of tyres, but the plan was of course to make this a three-stopper. This would allow him to sprint to the flag with a fourth and final stint back on options. In other words he was free to use those primes up with some quick lappery.
Ferrari didn't respond to Hamilton's stop. The team had a plan for Vettel and they stuck to it, and Maurizio Arrivabene was adamant afterwards that things would only have been worse had the team gone the three-stop route.
Meanwhile, Hamilton made it clear that he wasn't planning to make his set of primes last to the flag as he pushed as hard as he could.
He helped himself by getting past Kimi Raikkonen immediately after the stop, and then passing Bottas without too much drama. Both Finns were on very different strategies and there was no resistance.
Dealing with Rosberg
Hamilton moved into a temporary second place when Vettel pitted on lap 40, and then into the lead when Rosberg stopped on lap 45.
The timing of that stop was intriguing, for Rosberg emerged from the pits and blended in right behind his teammate. At the time it seemed to be more than co-incidental, and to his credit Toto Wolff was open about it afterwards.
"As Lewis was building the gap he needed ahead of Sebastian in his third stint, we actually compromised Nico a little bit by leaving him out longer than optimum before his second stop," said the team boss.
"This made sure the two cars didn't trip over each other on track, while running different strategies, and gave Lewis the clear air he needed to build the gap to secure P2."
In other words Mercedes adjusted Rosberg's strategy to ensure that he didn't come out in front of Hamilton – and in so doing he went a little past the optimum point for his own final stop.
Now given that at this stage Hamilton was chasing Vettel for second, you can understand why Mercedes saw a bigger picture, but at this stage Lewis still had a theoretical chance of catching Rosberg.
And Rosberg had now a) lost a little time by going past the optimum lap for his stop, and b) been denied the chance to keep Hamilton behind him.
The 'what if' scenarios
In the end it didn't matter, but what if somewhere along the way Rosberg had lost a little more time and Hamilton had indeed had the chance to catch and pass him in the closing laps? It might have made for an interesting debrief...
Hamilton made his third and final stop on lap 51, and his Plan B had worked to perfection.
Vettel struggled for performance on the prime tyre, and as he made clear over the radio, had some issues with traffic. When Hamilton came out of the pits for the 15-lap sprint to the flag, he was comfortably clear of the Ferrari.
The question was what could he do about Rosberg over those 15 laps? Hamilton had used options, while Rosberg was on primes that had been new at his stop, and which now had six laps on them. Hamilton of course began a charge, and the gap went 20.6s, 19.9s, 18.9s, 18.1s, 17.2s.
It was at this point, with around 9-10 laps to go, that we heard a fascinating radio conversation between Hamilton and the pitwall.
He was told it was time to "consolidate", and to "let him have this one".
Hamilton asked, "Is it impossible?" It made clear that if he did push, Rosberg was "going to respond".
Caution rules the day
It was understandable that Mercedes should take a cautious route. The team had a secure one-two, and as ever there were concerns about stressing the equipment when there was no need.
Had that been Vettel or anyone other than Rosberg 20 seconds ahead with 15 laps the team would no doubt have been encouraging Lewis, rather than putting doubts in his head and trying to rein him in when his instinct is to ran flat out – and challenge the one man who could deny him his third world championship.
It wasn't looking likely anyway, but the point is that anything can happen. If you put the leader under pressure, he can make mistakes.
Rosberg could have tripped over a backmarker and lost a few seconds here or there – or maybe hit the sort of late brake problems that slowed both drivers in the closing laps in Bahrain.
Hamilton wanted to be there, as close as possible, just in case there was any advantage to be taken.
In the end the closest he got was 12.8s with five laps to go before things stabilised. It looked like he had accepted the inevitable, although he made it clear afterwards that he wasn't happy about being told to back off.
"It's not nice for a driver ever to hear that," he said. "I'm here to race; I'm not here to finish second, so naturally I ignored that.
"I was pushing and really putting the car on the edge and when I realised there were seven laps to go, and I had 13 seconds and I was only seven-tenths of a second up, I had to take the smart approach and just bring the car home.
"But, still, it's not something you want to hear. So I'll definitely be making sure that that's not said again..."
Controlling the situation
As with the Rosberg pitstop timing, we saw the downside of having a world championship fight between two drivers with the same car: the team stepped in and controlled things.
Indeed you could even argue that asking Hamilton to back off was in some ways a 'correction,' guaranteeing that Rosberg had a safe win after his pit strategy was compromised to help Hamilton beat Vettel.
Again, one can understand why the team acted in the way it did, especially with Ferrari providing much stronger opposition than Mercedes did last year.
The team is no longer in a position to risk an all-out fight between its drivers. Nevertheless for those of us hoping to enjoy a no-holds barred fight between them it's a little unsatisfactory.
We now eagerly await a Monaco, an event where Rosberg thrives. And which produced a few headaches for the Mercedes management last year...