Is Rosberg turning the tables on Hamilton?

Could the tide be starting to turn in this season's Formula 1 world championship?

Lewis Hamilton still leads it by 10 points, but he's tasted defeat in three of the last four races and also trailed Mercedes team-mate Nico Rosberg during the first day of practice for this weekend's British Grand Prix.

Sure, this is only practice, but we saw a similar story last time out in Austria, which formed the bedrock of arguably the most impressive victory of Rosberg's F1 career thus far - despite the fact he messed up in qualifying and started behind Hamilton for the seventh time in eight races.

Of course if you examine the circumstances of the last four races things are not so clear-cut. Hamilton squandered pole in Austria with a bad start, but he was also slower than Rosberg at pretty much every other point of the weekend.

Hamilton won well in Canada, where Rosberg was hindered by a 'bad' set of tyres in qualifying and overheating brakes in the race, and Monaco was Hamilton's by right, where that strategic blunder by Mercedes handed it to Rosberg. But Hamilton was comfortably second best in Spain, where Rosberg scored his first win of this campaign.

Rosberg has had the prime spot in a lot of team celebrations of late© LAT

So in terms of individual performance it's neck-and-neck - a two-all-draw in football parlance. But that still represents a shift in favour of Rosberg, who was comfortably beaten by Hamilton in each of the first four races of 2015.

There are suggestions Hamilton is unhappy with a clutch modification introduced ahead of May's Spanish GP, and that this probably cost him victory in Austria, but there was nothing wrong with the starts he made in Monaco and Canada, remember.

We have got used to Hamilton suffering setbacks and bouncing back spectacularly. Think of last year's Hungarian GP, where his car caught fire in qualifying, relegating him to the back of the grid. Yet he still stormed through the field to beat Rosberg.

There was a general feeling that Rosberg could not quite muster the necessary verve to pull off similar turnarounds if things went against him, yet at the last race he overturned his qualifying deficit to win, and there were further encouraging signs of a new 'steel' at Silverstone on Friday.

His Mercedes let him down early in practice one, grinding to a halt thanks to a loss of hydraulic pressure in the gearbox, but the way he recovered to top the session, with two late laps good enough to eclipse Hamilton, was very impressive.

He continued his good form in the heat of the afternoon, setting the fastest time of the day on the medium tyre (only a tenth up on his morning best on account of less favourable conditions).

Hamilton was unhappy on Friday © LAT

Hamilton seemed to struggle in the later session, complaining at one point over the radio that his Mercedes was "all over the place", and he admitted afterwards that it was "not the easiest of days".

But on the bright side he said the feeling from his clutch had returned to something like the opening four rounds, so those who think Rosberg 'lucked' into victory in Austria thanks to a poor Hamilton getaway should - if both qualify on the front row, as one would expect - get to see a straight drag race this time.

The longer runs (though still relatively short in the grand scheme of things, thanks to a couple of unfortunate red flags) did not make for better reading for Hamilton, who trailed his team-mate by roughly half a second per lap over a five-lap stint on the mediums, and told the team it was "not possible" to achieve the high 1m38s laps they asked of him during the run.

Neither driver was particularly happy with their car's balance during a hot and windy session, and with conditions expected to be cooler come Sunday's race perhaps this won't matter, but Hamilton is certainly on the back foot as things stand.

Nevertheless, he's bounced back from tougher situations than this before, and will doubtless be buoyed on by the expectant home crowd.

The question is whether he will meet far sterner resistance from what looks to be a genuinely improved Rosberg on the other side of the garage.

THE FERRARI 'CHALLENGE'

Reading into Ferrari's Friday form has become an exercise fraught with the perils of a false dawn. Even its team principal Maurizio Arrivabene has grown frustrated by his squad's propensity to flatter to deceive with strong pace on the opening day of a grand prix weekend, only to fall away on the days that count.

Ferrari split the Mercedes but often falls back after Friday © LAT

Friday at Silverstone followed the usual pattern, with both Ferrari drivers lapping a few tenths adrift of Mercedes' outright pace (though Kimi Raikkonen could have been faster had he strung his best sectors together) but fractionally faster over the comparative longer runs.

There is little point suggesting Ferrari will pose a serious threat to Mercedes here. That's based on recent form, the fact Mercedes has introduced upgrades to the W06 (which the team was likely trying to hide from view when it was reprimanded for covering Rosberg's stricken car illegally in first practice), and the likelihood race day will be cooler than Friday, which doesn't generally suit the SF15-T.

The focus should be on ensuring it doesn't give away a podium finish for the third race in succession. Grateful recipient of those two recent gifts has been Williams, which superbly charged from the rear of the grid to second at this race last year with Valtteri Bottas.

Hamilton suggested it would be difficult to know whether Williams or Ferrari would be "the biggest threat" to Mercedes here, and we can obviously expect the improved FW37 to get quicker when it is turned up to full blast on Saturday and Sunday, as is the norm.

But Bottas is concerned by the car overheating the medium tyre over a single lap, which could hurt its chances in qualifying, and his longer run did not suggest that Williams will be in prime position come Sunday either.

LONG RUN AVERAGE ON THE MEDIUM TYRE (OVER FIVE LAPS)

Toro Rosso showed superb pace © XPB

• Toro Rosso (Max Verstappen) 1m38.502s
• Ferrari (Sebastian Vettel) 1m38.920s
• Mercedes (Nico Rosberg) 1m38.972s
• Red Bull (Daniel Ricciardo) 1m39.318s
• Force India (Nico Hulkenberg) 1m39.574s
• Lotus (Romain Grosjean) 1m39.899s
• Williams (Valtteri Bottas) 1m40.206s
• Sauber (Marcus Ericsson) 1m41.527s
• McLaren (Jenson Button) 1m41.662s

Red Bull and Toro Rosso expected the higher downforce demands of Silverstone to suit their cars. Daniil Kvyat was very fast over one lap on the harder tyre early on in the second session, while Max Verstappen's long-run pace on the faster medium tyre looks very impressive (with the usual unknown relative fuel load caveat).

Given how similar this circuit is in terms of demand to Barcelona, one would expect Red Bull and Toro Rosso to be stronger here than at the recent 'power' tracks of the Red Bull Ring and Montreal.

But the podium is still probably beyond reach. Daniel Ricciardo reckoned Red Bull (armed with its new front wing on the RB11) might be able to stay ahead of Williams, depending on how much of a leap the Grove outfit makes on Saturday, while Toro Rosso will need to focus on avoiding the sort of race day disaster that turned top-six qualifying form at Barcelona into only two points.

Updates encouraged Red Bull © LAT

Toro Rosso's youngsters are bullish, and both driving well, but they must beware the trap of over-expectancy. They will also need to be wary of a renewed threat from Force India, which has performed strongly at the last couple of races, as upgrades have been drip-fed onto the VJM08.

Its predecessor struggled on the windy fast sweeps of Silverstone last year, but the performance of Nico Hulkenberg in particular so far this weekend (eighth fastest overall and decent over a longer run) suggests Force India's major 'B-spec' aero upgrade has allowed it to maintain its recent level on a circuit at which it was woefully off the pace last year.

Fellow Mercedes engine customer Lotus is likely to improve substantially, having suffered a difficult Friday in which Romain Grosjean lost much of his running in second practice after finding the gravel at Luffield, following a clutch problem that hindered team-mate Pastor Maldonado in practice one.

The E23 has generally been strong in race trim on the harder tyre compounds so far this year, which should provide some necessary optimism for the rest of the event.

Further back, McLaren and Sauber are really struggling. The updated MP4-30 is looking difficult to drive here, on top of the known current weaknesses of the Honda engine, while Sauber - a marginal points contender with an outdated engine spec in Canada and Austria - looks exposed for not yet substantially upgrading the C34 chassis on a circuit that requires good levels of downforce.

Conversely, Manor seems to have made a step forward, after introducing an update package to the MR04. Comparing its outright pace on Friday here to that shown ahead of May's Spanish GP suggests the car is 1.46 per cent closer to the Mercedes benchmark.

The team is still in a race of its own at the back, but that's nevertheless an encouraging sign for F1's minnow.