Why was Lewis Hamilton off the pace in Monaco qualifying?

Tech Corner: Why is Mercedes struggling in Monaco? (1:42)

Sam Collins joins Jennie Gow in a Monaco Tech Corner, to discuss why Mercedes isn't showing its usual pace. (1:42)

MONTE CARLO, Monaco -- An inability to keep all four tyres in the correct working range saw Lewis Hamilton fail to make the top ten shootout during qualifying in Monaco, but Mercedes was at a loss to explain why he struggled so much.

In a session that saw teammate Valtteri Bottas qualify 0.045s off pole position, Hamilton finished 14th fastest with a time nearly two seconds off the pace. A series of error-ridden laps in the second stage of qualifying saw him knocked out ahead of the top-ten shootout in Q3 and he will start 13th on Sunday's grid once Jenson Button's grid penalty is factored in.

"I was devastated after the session, to the point that I couldn't get out of the car," Hamilton said on Saturday evening. "So much energy and work goes into these weeks, collectively as a team and individually and the way you prepare yourself.

"And when you see the other car is capable of making it work and you can't think of why you aren't able to and it feels it's like a mystery, because none of us can really understand it. So, yes, it's difficult. When you don't get into Q3 your weekend is pretty much done and it's really about trying to recover as much as you can."

What went wrong for Hamilton?

Monaco's low abrasion surface and this year's harder compound tyres meant a number of drivers struggled to get the most out of their car in qualifying. Trying to get the front and rear carcass temperature in the correct window at the same time without overheating the surface of the tyre is a fine balancing act, and Mercedes struggled more than most. As Bottas proved, the W08 was quick when all four tyres were in the window, but finding a setup that can achieve that for a single lap has proved a problem ever since the team started down the wrong setup path on Thursday afternoon.

"You can say there is a certain DNA in the car and I think we have proved that our car can go very quick in qualifying and the race, but it seems to be more of a diva to get it into the right window," team boss Toto Wolff explained. "Probably it is marginal differences that make it drop out of the window, we just need to get on top of this and we have a great team that has shown in the past that its strength is in analysing the data and finding out how to put it on the track on Friday and then develop it over the weekend.

"This is one of the outcomes we've had in the past, we've had it in Singapore for different reasons but this is the second weekend that comes into my mind after three years or four years where we have struggled really bad from the get go and from FP2 with the setup."

Hamilton topped the opening practice session of the weekend on Thursday (setting a faster time than he did in qualifying on Saturday) but has struggled since then. His three best sectors from Q2 would have been enough to make the cut for Q3 and his final lap looked quick enough too before Stoffel Vandoorne's accident brought out yellow flags in the final sector. But the mystery is why he couldn't consistently set fast sectors.

"It's a very, very strange thing because I did the same thing as I do always when I leave the garage, the same thing I did in FP1, but it's just a case of the tyres going in and out, in and out, in and out [of the temperature window]. Mostly they're under the temperature, and it's not just the fronts or the rears -- it could be just one tyre, and another tyre... So, in general all tyres were not in the window."

Why was Bottas so much quicker?

Bottas' Q2 lap was 1.2s faster than Hamilton, but he also reported the same issues in the team's post-qualifying briefing. Unlike the Ferraris that could set a fast time immediately after their outlaps from the pits, the Mercedes drivers needed an outlap and a preparation lap to get the most from their tyres. It seems Bottas, who had the same setup, was better at that tyre preparation than Hamilton.

"We can't combine both of the axles, front and rear, to be on the optimal window with the temperatures at the same time," Bottas said. "So it takes two, three laps to build temperature up to all of the tyres and then to get the balance right and get the feel for the car and the confidence. That's been a bit of an issue. Plus, we had some set-up problems in practice two -- so not the easiest weekend. Definitely they [Ferrari] would be more in the window with everything and their car seems very driveable and stable."

Wolff believes Hamilton may have been closer to Bottas' pace had he made Q3 and also suspects the gap to pole position would have been larger if Sebastian Vettel had extracted the Ferrari's true potential.

"We have seen Lewis perform really well in Monaco and outperform many others, so I don't know what happened today," Wolff said. "The longer qualifying took, the better somehow the car worked for Valtteri. Whether it was finding out how it drives or just getting more laps under his belt, but in the debrief the two drivers described the same characteristics of the car and Valtteri felt it was very difficult as well.

"We haven't seen the Vettel lap, I think he made some mistakes in his lap, and I don't think we've seen the Ricciardo lap. I wouldn't say the pace we had today was close to Ferrari, I think they could have gone faster."