Why Bottas's defeat was more than just a bad start

This was Valtteri Bottas's weekend, or so it seemed. From the start of practice until the moment the lights went out for the start of the Spanish Grand Prix, he was the faster Mercedes driver and had illustrious team-mate Lewis Hamilton emphatically covered.

Then, in a reverse of the start of the Australian Grand Prix, Hamilton made the better getaway from second on the grid and led all but the first 400 metres of the race to seal a remarkable fifth consecutive one-two finish for Mercedes.

But despite the Circuit de Barcelona Catalunya being notoriously difficult to overtake at, there was a little more to this than Hamilton turning the tables by getting ahead then parking in front of Bottas.

In race conditions, Hamilton showed no signs of the kind of deficit to Bottas that existed in practice and qualifying even if you consider that the 0.634-second gap in qualifying was an exaggerated deficit thanks to Hamilton's preparation for the lap being compromised.

It added up to a crushing win for Hamilton. Not only did he defeat Bottas, but he also spearheaded a Mercedes team that annihilated Ferrari and Red Bull despite the usual raft of upgrades that many hoped might threaten the supremacy of the Silver Arrows.

The start was critical for Hamilton, although a more complex confluence of factors in the early seconds of the race gave him the lead. First of those was Bottas making a poor initial getaway thanks to a clutch problem, which he emphasised was very different to the wheelspin over the startline that cost him the advantage at the start of last month's Chinese GP.

"China was a bit more my own fault and I definitely could have done something better there," said Bottas. "Here, if I could do it again, I wouldn't do anything different.

"We can definitely see the vibration on the clutch and the abnormal behaviour, which cost me that few crucial metres on the way to Turn 1."

Bottas described the feeling as that of the clutch rapidly engaging and disengaging. The team has yet to explain what caused the problem, although often this is a consequence of the clutch being too cool.

But this only allowed Hamilton to do part of the job of getting ahead. In the early moments of the race his front axle drew alongside Bottas but the Finn did still have an advantage heading into the braking zone. Even though Hamilton had the inside line, there was still a move to be completed on the brakes - which is where things became complicated.

"Obviously I did Lewis a favour because I distracted Valtteri" Sebastian Vettel

Vettel, who started third, initially picked up the tow from Bottas then moved to his outside on the run to the Turn 1 right-hander. While Hamilton was outbraking Bottas on the inside line, Vettel tried to go the long way round. He left his braking late, too late, and locked up the inside-front.

"I wanted to brake latest, which I think I did," said Vettel. "Obviously Valtteri was also quite late and I could not really get in, and I couldn't see him so I knew he was there. I saw that he was also braking quite late and if I just turned in, which I think I could have managed, then he would have nowhere to go and I would go the other way. It didn't work.

"In the end, obviously I did Lewis a favour because I distracted Valtteri. It was clear that I couldn't win the race at the first corner but I saw there was something to try."

Remarkably, the three made it round with Vettel only briefly straying beyond the extremities of the track. Bottas was in an awful position between the two, but drove brilliantly - and respectfully - to avoid contact. Vettel was briefly ahead, but was wide and Bottas caught the rear as it snapped while he went past the Ferrari to reclaim second place.

The real winner in all this was Max Verstappen, who had watched the first corner unfold and briefly slipped behind the Ferrari of Charles Leclerc having had to go conservative into Turn 1 when confronted with a wall of three cars in front.

When Vettel rejoined after his brief wide moment, he ran deep into the Turn 2 right-hander and forced Leclerc wide, allowing Verstappen to move back up to fourth. Then when Vettel had a wobble into Turn 3, Verstappen went around him to take third.

As the first stint progressed, it became clear that Bottas didn't have the pace to stay close to Hamilton. Early on, after dropping two seconds on the first lap, Bottas didn't stray too far from the leader's wake.

The time loss was mild and by the start of lap 19 of the 66 the gap had grown to 3.965s - not close enough for Bottas even though the negative effect of turbulent air at this track can still just about affect a car that far back, but only a loss of 0.104s per lap on average since the opening lap. By Barcelona standards, he was still in the game. But with tyres ageing and backmarkers coming into play, things then got away from him.

On lap 19, Hamilton took half a second out of Bottas, but the killer was lap 20 on which he was almost two seconds faster thanks to banging in the fastest lap of the race while Bottas cleared Antonio Giovinazzi's Alfa Romeo and Robert Kubica's Williams. That stretched the gap to 6.349s. Over the next five laps, Hamilton was 0.774s a lap quicker than Bottas, who was 10.221s behind at the start of his in-lap. Game over.

"I had to go through some of the slower cars and, at the same time, my tyres started to drop off," Bottas.

"With less surface on the tyre I lost a bit of temperature. So my tyres were finished much earlier than Lewis's. That's why the gap became bigger. Probably I was sliding the car more during the first stint and he made a gap there."

This was an old Bottas weakness re-emerging, one that has been largely mitigated this year by the thinner-tread Pirelli tyres. In his previous two seasons at Mercedes, he has often struggled to keep the tyres alive for as long as Hamilton and this played a part in any vague hope he had of being able to get back ahead into the lead being eliminated.

There's little doubt he would have held the lead had he stayed ahead at the start, but while accelerated tyre use while in Hamilton's wake did contribute to his struggles at the end of the stint, history suggests it wasn't the sole factor.

Fortunately for Bottas, there was no real pressure from behind. Verstappen held third place, and while he hadn't vanished he didn't show any hints of the pace needed to attack the Mercedes drivers. Red Bull knew its battle was with Ferrari so was focused on the two red cars behind.

The front-right flatspot Vettel picked up was hurting both him and team-mate Leclerc, who was stuck behind him. It took too long for Ferrari to make the switch, which Vettel agreed to and executed at the start of lap 12, by which time the gap to Verstappen had grown from 1.337s at the end of lap one to almost six seconds. Leclerc, once in free air, did start chipping away at Verstappen but only by a tenth of second a lap. This ensured he was well out of undercut range.

Vettel dropped back from Leclerc by three quarters of a second per lap and complained constantly over the radio about his tyres. Such was his desperation to get new boots that he insisted he was happy to be dropped into traffic if Ferrari could not find him a gap.

He eventually stopped at the end of lap 19 to switch from softs to mediums and, although Plan A was still not to pit again, realistically a second visit was likely. A cross-threaded left-rear wheelnut didn't help, ensuring Vettel's pitstop took twice as long as it should have done.

He rejoined behind the Toro Rossos of Daniil Kvyat and Alex Albon down in 10th place, although with the pitstops following thick and fast he didn't lose much time and was back up in fifth by lap 26.

This led Red Bull to pit Verstappen, opting for a second set of softs and committing to a two-stop strategy, coming in a lap later. Leclerc followed five laps later and took hards - also with a double-time pitstop thanks to a crossthread on the left-rear.

By now it was clear that Vettel was also two-stopping, and after Leclerc's stop we once again had a faster Ferrari behind a slower one. Vettel followed Leclerc for an inexplicable 10 laps before finally being let through on lap 36. Vettel eventually pitted on lap 40, having been the fastest car on track once in clear air and lapping eight tenths faster than Leclerc.

The pitstop timing at least was a good move, as it gave Red Bull something to think about. Verstappen then made his second stop for mediums on lap 43 at a point where the team knew he would likely have to catch and pass Leclerc while still ensuring he had a decent margin over Vettel, who was six seconds behind after the stops. Leclerc had an advantage of a little over four seconds, and Verstappen hacked three seconds out of that on lap 45 alone before the safety car intervened.

This was thanks to McLaren driver Lando Norris's ill-fated attempt to pass Lance Stroll's Racing Point for 14th at Turn 1. Stroll defended the inside, Norris tried to hang on around the outside but found himself squeezed at the exit. He tried to back out, couldn't, and they made contact - both retiring. The stewards' verdict: racing incident.

By this stage of the race, Mercedes had already decided to cash in its advantage to take a 'free' second stop with both drivers. Bottas had just come in from second place on a stint where he was actually fractionally quicker - by 0.162s per lap - than Hamilton, but still 7.5s behind.

The race leader, whose right-rear was not in a great condition, was due to come in a lap later and he did, but by then under safety car conditions. Ferrari opted to pit Leclerc, who rejoined fifth ahead of Gasly, meaning Verstappen moved up to third with Vettel in tow.

When the race restarted with 14 laps remaining, the top six remained unchanged - with only Gasly's initial attack on Leclerc hinting at a possible switch. During this phase, with nothing left to fight for, Hamilton was on average just over two tenths per lap quicker than Bottas (disregarding the last lap on which he slowed) and crossed the line four seconds to the good. On the way, both drivers had a tilt at fastest lap, which went to Hamilton by a quarter of a second.

"We brought some upgrades and we were expecting to be in the fight but that has not been the case" Mattia Binotto

Hamilton was delighted to have taken the victory, and was much happier with his performance in the race than over a single lap. When asked to explain the swing from Saturday to Sunday, and whether set-up differences played a part both in that and the fact he is able to eke more life out of the tyres than Bottas, he confirmed the cars were similar despite last-minute tweaks to his to improve the balance.

"The cars are pretty much set the same, so that [extending the tyre life] is how I drive the car," said Hamilton. "I drive the tyres slightly differently in the race, and often I'm able to eke them out a little bit more.

"The car is obviously great, but I've generally struggled with the car since Australia. Valtteri has settled nicely into the car, he's quite happy. There are definitely areas I'll continue to focus on at the factory and this week, so I'll be dialling in to try to really understand."

But what's clear is that Mercedes is ahead, emphatically. With aggressive car upgrades to come and its own engine update still to arrive, there's no reason to expect this run of success to let up any time soon.

As for Ferrari, it needs to take a long, hard look at its car concept and ask whether the trade-offs it's made in terms of where it's generating its downforce are the right ones. Mercedes is looking stronger as the season progresses, not weaker, and such is the team's advantage and operational effectiveness that it's hard to see where the first non-Silver Arrows win will come from.

Verstappen, who many would legitimately have tipped as favourite for the next race in Monaco two months ago, certainly isn't confident - having described the Mercedes as superior to the Red Bull in all types of corner.

"Back in Baku was pretty strong, but people come here with upgrades and clearly we lost out a bit to Mercedes - but it seems that we did catch up to Ferrari," said Verstappen.

"For Monaco, looking at the low-speed performance in the last sector, we are clearly not the favourite and I don't expect it to be like last year when we were super-strong in Monaco."

Ferrari team principal Mattia Binotto will have been disappointed to have seen Mercedes pull away. This weekend was the acid test of his team's prospects, particularly given engine upgrades tend to give the biggest single performance gains - and Ferrari fell short.

"We are disappointed with the performance in the weekend," said Binotto. "We brought here some upgrades, aero and engine, and we were expecting to be in the fight but that has not been the case.

"The upgrades worked well. I think power-wise and on straightline speed we are good enough but certainly we have some weaknesses on the car that were highlighted this weekend. It is up to us to try to understand, to work, to assess and to improve in the future."

But while the car has weaknesses, they aren't overt. There's no fundamental balance problem, even if Vettel isn't completely happy with the feel of the car, and engine performance is a real strength - yet the lap times just aren't good enough. In the slow stuff, in particular, the Ferrari simply can't carry the speed the Mercedes does.

This season is looking more and more like 2016, when Mercedes dominated and the title fight was an exclusively intra-team affair.