How Lewis Hamilton lost the 2015 Monaco GP

Twelve months after Hamilton's calamity, it's easy to forget just how dominant the reigning world champion was around Monte Carlo's mean streets last May.

"Only in the early phase of qualifying did he look anything other than in control," noted Sky F1's Martin Brundle. Pole position - remarkably, the first of Hamilton's F1 career at F1's most famous venue - was achieved with over three tenths of a second to spare. On race day, Hamilton remained a class apart, opening up a 24 seconds lead over Nico Rosberg as the grand prix wound go down to its final ten laps.

But then Max Verstappen crashed out, a Virtual and then a full Safety Car was deployed, and everything changed.

Except it didn't need to. Worried that Ferrari would call in Sebastian Vettel for a 'free' stop and a new set of soft tyres for the restart, Mercedes had already u-turned on a plan - articulated to Hamilton over the team radio - to pit the race leader for a fresh set of tyres when Hamilton himself urged the team to call him in.

But why?

Taking a glance at a trackside big screen, Hamilton thought he had seen Rosberg, running behind him in second place, pit for new tyres, leaving him to assume he would have been at a tyre disadvantage at the restart.

"Guys, that's not good," Hamilton urged. "These tyres have lost all their temperature. Everyone is going to be on options now."

But just because a driver calls for a pit-stop doesn't mean that a driver will be called in.

The crux of the matter - and the mistake that was to lost Hamilton the race - was Mercedes' mistaken belief Hamilton had a sufficient lead to pit and return in front of both Rosberg and Vettel.

Their calculations hadn't taken into account the time Hamilton was losing when running behind the Virtual Safety Car and the full Safety Car.

"We had a problem in the maths. The calculation we had was actually giving us a bigger gap than we had," conceded Mercedes boss Toto Wolff. "We had one second to react and, combined with our wrong timing data, we made the mistake of calling him in."

But Rosberg and Vettel hadn't stopped. And nor did they stop when they reached the pitlane entry.

First Rosberg and then, by the narrowest of margins, Vettel passed Hamilton in the pits and as he returned to the track, the Englishman suffered that gut-wrenching sinking feeling.

"What's happened guys? Guys, what's happened?" he called out to race engineer Peter Bonnington. "I've lost this race, haven't I?"

He had.

Having stopped to cover off the threat of Vettel and Rosberg on fresher tyres at the restart, the devilish irony was that, despite his superior speed and new boots, Hamilton couldn't find a way past the Ferrari over the final ten laps - which just highlighted what a grievous mistake the team had made.

"Even if Vettel had stopped, Mercedes would still have had track position," noted a bemused Ted Kravitz. "Track position is king here and even on the quicker tyre Vettel wouldn't have been able to get past, just like Hamilton wasn't able to get past."

After the race, the sight of a crestfallen Hamilton on the podium, unable to hide his devastation, became the definitive image of the day.

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In the subsequent press conference, Hamilton accepted culpability. "I saw a screen, it looked like the team was out and I thought that Nico had pitted," he told reporters.

"The team said to stay out, I said 'these tyres are going to drop in temperature,' and what I was assuming was that these guys would be on options and I was on the harder tyre. So they said to pit. Without thinking, I came in with full confidence that the others had done the same."

But as Wolff later remarked: "It was our decision to call him in and our mistake, pure and simple; in these situations, a driver trusts his team."

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Not only had Mercedes made a fatal mistake in their calculations but they had failed to reassure Hamilton that Rosberg hadn't pitted - and nor was he likely to. But equally baffling for many was Mercedes' decision to pit Hamilton when, even in their best-case scenario, the margins were so slender.

"The team incorrectly thought they had three or so seconds in hand which still very much begs the question 'why risk it?'' argued Brundle. "Hindsight is a wonderful thing, but to so many people at the track and at home it just looked like a crazy decision - and so it proved to be."

Radio gaga: How Hamilton lost the 2015 Monaco GP

Peter Bonnington: "So, just a reminder, you are in your Safety Car... Virtual Safety Car. Virtual Safety Car. So look at your dash, look at the boards. Keep positive. Stay positive. And you are staying out."

PB: "So we are staying out and you are just staying positive."

PB: "Okay, Lewis, a Safety Car has been deployed."

Lewis Hamilton: "Are you sure it's the best thing to stay out?"

PB: "Nope, we will be boxing the end of the lap. Boxing the end of the lap. So just stay positive. Stay positive. We are going to go +1 ½ turns for the option tyre unless you tell us different."

PB: "Okay Lewis, just give us pit confirm."

PB: "Okay, so we are now staying out. Staying out. Staying out. Just confirm on the radio."

LH: "Guys, that's not good. These tyres have lost all their temperature. Everyone is going to be on options now."

PB: "Okay. Copy, copy. Box, box. Box, box."

PB: "So, cancel brake magic. Cancel the brake magic."

PB: "Caution on pit entry."

PB: "RS modes. RS modes."

PB: "So, cancel RS. Watch the line on pit exit."

LH: "What's happened guys? Guys, what's happened?"

PB: "Okay, Lewis, so we got caught behind. So we're just getting a look now, just having a look now. Just reviewing the video. So stick the brake warming on, let's get some temperature into these brakes."

PB: "Okay, Lewis. So we have lost the marshalling system so we may need to do something to override DRS."

LH: "I've lost this race, haven't I?"

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