Why Mercedes needs to watch its back in Malaysia

On the bare face of it, the Mercedes Formula 1 team should feel utterly relaxed about its prospects for the Malaysian Grand Prix.

Lewis Hamilton and Nico Rosberg finished both of Friday's free practice sessions one-two on the timesheet, with a chunky gap back to their nearest rivals.

Rosberg was more than a second clear of Kimi Raikkonen's Ferrari in FP1 at the Sepang circuit, and although Raikkonen's team-mate Sebastian Vettel got closer in FP2, Hamilton still enjoyed a comfortable advantage of more than six tenths of a second.

Game, set and match, right? Well, not necessarily.

Mercedes did not enjoy anything like that kind of significant edge over the longer runs in the second free practice session.

In fact, Red Bull's Max Verstappen stole the show here, lapping quicker than both Mercedes drivers, Ferrari's Vettel, and the other Red Bull of Daniel Ricciardo, during the most-representative race runs of the day.

Often the Mercedes drivers don't complete many laps over the longer runs on GP Fridays, perhaps safe in the knowledge they usually have an inherent advantage over the rest already, so don't need to wear out their cars amassing tonnes of data.

But Sepang has been completely resurfaced this year, which means all the teams are on a journey of discovery with the Pirelli tyres.

The general consensus suggested the circuit is smoother and definitely offering up more grip. Hamilton's session-topping laptime of 1m34.944s in FP2 marked the first time F1 cars have gone below 1m35s since 2011.

But, as McLaren's Jenson Button said, the surface was still "tricky' to read.

"It's very strange," he said. "You get a false sense of hope with the new asphalt - you feel like you have a lot of grip and then suddenly it's taken away from you.

"It doesn't feel normal, it feels like Sochi. It's tricky asphalt. We're the best guys in the world, and we normally feel when we're getting oversteer, but with this it just comes out of nowhere."

All meaning Mercedes couldn't afford to rest on its laurels in practice. It has the fastest car in F1, but the sensitive Pirelli tyres play a large role in defining competitiveness, and they have caught Mercedes out on occasion.

Hamilton, Rosberg, Verstappen, and Vettel all completed significant 10-lap runs on the soft compound, which they are all likely to start the race on if they qualify inside the top 10 as expected.

Mercedes' one-lap advantage on pure pace means it may be able to get through Q2 on a different compound - Hamilton's 1m35.956s lap on the hard tyre was fast enough to put him fifth in FP2, while Rosberg managed a 1m36.543s effort on the medium that was just about good enough to make the top 10.

Starting the race on the harder tyre could buy strategic advantage, but the risk of getting overtaken off the start line is much greater in that instance - as Rosberg found almost to his cost in China earlier this season.

And that's the real danger facing Mercedes here this weekend. If for some reason it cannot convert its single-lap pace advantage into superior track position on Sunday, it stands a very real chance of losing the race.

The graph shows that Verstappen set off at a much quicker pace than the rest, but was able to stay quicker than all of them for the first half of his stint.

Even when his pace dropped away, and the Mercedes drivers pumped in some fast laps midway through their respective runs, Verstappen was still able to hold onto his tyres well enough to regain the upper hand over the final two laps of his stint.

Vettel too was right in the mix with the Mercedes for the first half dozen laps, before his pace dropped away irrevocably.

Verstappen's laptime average over that stint was 1m40.498s, compared to 1m40.742s for Hamilton, 1m40.764s for Rosberg, and 1m40.895s for Vettel.

Raikkonen managed an even quicker 1m40.494s average right at the end of FP2, but his run is less representative, having been conducted at a different time and over half the number of laps completed by his rivals.

The situation looks even more encouraging for Verstappen on the medium tyre. He lapped in 1m39.773s on average over a five-lap stint on that compound, compared to 1m40.449s for Rosberg, 1m40.747s for Ricciardo, and 1m40.754s for Vettel.

It should be noted the Red Bulls did shorter stints of only five flying laps on this tyre, compared to seven for the Mercedes and nine for the Ferrari.

But no wonder Verstappen declared this a "positive day" for his side of the Red Bull garage.

"The long runs look very strong," he said. "It felt like I could do what I want with the car. I could throw it into the corner like I wanted to, and that's always positive."

Hamilton did no long running on the medium tyre; instead logging laps on the hard compound that Pirelli has mandated must be used at some point during Sunday's race.

The reigning world champion averaged 1m40.217s over a five-lap stint on that compound, which was only 0.016s quicker than Raikkonen's Ferrari managed over a stint of 12 laps on the same tyre, but much earlier in the session when the track was greener.

All told, it looks as though Mercedes has little or no race-pace advantage on any of the various tyre compounds here, which suggests it could struggle to counter-attack its rivals should they somehow steal track position away on Sunday.

Mercedes suffered that fate at this circuit last year. Hamilton and Rosberg qualified one-two but fell behind Vettel's Ferrari after deciding to pit under an early safety car. Once in front, Vettel couldn't be stopped.

The onus will be on Mercedes to prevent a repeat. If the new track surface continues to be Sochi-kind to the tyres, the chances of overhauling rival cars with alternative strategy will be substantially reduced.

So Mercedes will have to do its damage in qualifying and at the start of the race.

The good news in this regard is that its single-lap speed looks mighty at the moment.

PURE PACE RANKING
1. Mercedes (Hamilton) 1m34.944s
2. Ferrari (Vettel) 1m35.605s
3. Red Bull (Verstappen) 1m36.037s
4. Force India (Perez) 1m36.284s
5. McLaren (Alonso) 1m36.296s
6. Toro Rosso (Sainz) 1m36.836s
7. Renault (Palmer) 1m36.940s
8. Williams (Bottas) 1m37.016s
9. Haas (Gutierrez) 1m37.048s
10. Sauber (Ericsson) 1m37.449s
11. Manor (Wehrlein) 1m37.878s

That advantage at this stage is bigger than Mercedes has enjoyed at either of the past two Malaysian GPs.

Hamilton also looks back in his groove after a difficult weekend in Singapore last time out.

There is nothing substantially different with his car here, but the chance to reset mentally after the disappointment of getting out-driven by Rosberg on the streets of Marina Bay is clearly working wonders.

There was only hundredths to choose between the two title rivals through sectors one and three of the lap, but Hamilton was able to find a crucial 0.151s advantage in sector two, which runs from Turn 4 to the exit of the hairpin at Turn 9.

"At the moment it's a good feeling," said Hamilton, who ended the second session 0.233s clear of Rosberg. "No issues with the car, very few mishaps on the track. Generally we were able to bank lap after lap after lap.

"We got through all of our running so there's not really any excuses for us now. Fingers crossed we're in a good position."

The fact Red Bull seemed to struggle to extract single-lap speed from the RB12 also plays into Mercedes' hands.

Neither Red Bull driver managed a good first sector on their quickest laps, and were also disappointingly slow through the second sector, which should be the part of the circuit that plays most to the car's strengths.

"Still a bit to find definitely, on low fuel and high fuel," said Ricciardo, who was slower than Sergio Perez's Force India and Fernando Alonso's McLaren-Honda over a single-lap in FP2, and also some way off Verstappen's pace over the longer runs.

"We didn't find a big gain on low fuel. High fuel, we just struggled basically - not so much keeping the tyres in a good window, but trying to get the grip out of the tyres.

"The new surface definitely has more grip in it, so that's a positive, but we didn't find as much as the others.

"We did expect Ferrari to be quite quick here. Obviously last year they had some good success. Personally, I'm a bit too far off the pace. We can get closer."

Ultimately, Red Bull seems to have superior race pace, but looks unlikely to qualify better than fifth, while Ferrari looks to be Mercedes' potential nearest challenger - if it has one - in qualifying, but lacks any advantage in race trim.

So it seems all Mercedes needs to do is qualify on pole and make it into the first corner ahead in the race.

But as we've seen occasionally in the recent past, even with F1's dominant car at your disposal that is sometimes easier said than done.