Pole king Lewis Hamilton cautious ahead of Belgium Grand Prix
Lewis Hamilton believes Sunday's Belgian Grand Prix is impossible to predict despite storming to pole position.
Hamilton claimed his sixth consecutive pole with a flawless lap in qualifying at an sun-drenched Spa-Francorchamps.
The world champion, bidding for his first victory since 2010 at this most historic of Formula One venues, was almost half a second clear of his title rival Nico Rosberg.
It sent out an emphatic message to his Mercedes team-mate who left the track on Friday night believing he was "one step ahead" of Hamilton after dominating practice.
But the roles were reversed here, and on Saturday's form at least, Rosberg faces an uphill challenge to take the fight to Hamilton.
Yet the Briton, who joins a small club of drivers to secure six straight poles, believes the new start procedure - which places greater emphasis on the driver rather than the pit wall - makes Sunday's race tough to call.
"It is really difficult to know what is going to happen tomorrow," said Hamilton, 21 points ahead of Rosberg in the championship.
"I have got a good team behind me who prepare me as well as possible to get good starts. It is going to be difficult but everyone is in the same boat."
The nature of this track, with the long run up to Les Combes - the scene of Hamilton's crash with Rosberg last year - means it can be a disadvantage starting from the front of the field. Indeed only five of the last 13 pole-sitters have gone on to win.
"It is not a very good place to start from pole," Hamilton added. "When you are up ahead you create a great tow for whoever is behind.
"In the perfect scenario I will get a mega start out of turn one and I'll be enough car lengths ahead, but that is never the case generally.
"I can't look into it and hope I will get the second best start and come out behind Nico - that is not a good way to approach it - so I have just got to try and stay in the lead as otherwise it will be a tough race. If you're behind it is very difficult to overtake here."
Rosberg, who has lost out to Hamilton at all but one of the 11 races this season, was at a lost to explain his performance.
It is the second qualifying session in a row where he has finished half a second down on his team-mate, relative light years in Formula One.
"I was expecting to be on pole so it came as a big surprise," said Rosberg. "Getting out of the car and looking at the times - that he again improved his time - was very surprising and very annoying.
"He pulled that extra little bit out of the bag that I wasn't able to do."
Behind the Mercedes pair, Valtteri Bottas was third in his Williams with Romain Grosjean an impressive fourth for Lotus, although the Frenchman will be demoted five places following a gearbox change.
Sebastian Vettel, who won the Hungarian Grand Prix, could manage only ninth at his 150th race. His Ferrari team-mate Kimi Raikkonen stopped on track after a loss of power. He will start only 14th.
McLaren fell at the first hurdle in qualifying but such is their demise this season it came as little surprise. Jenson Button finished 17th, half a second ahead of his team-mate Fernando Alonso.
As has been the theme this weekend, only the Manor pair of Will Stevens and Roberto Merhi were slower, but both Button and Alonso will be demoted to the final row.
The pair have taken on an eighth Honda engine of the campaign - their second of the weekend - and following a raft of replacement components, were subjected to an unprecedented 105-place grid drop.
With only 20 cars on the entry list, their punishment is confined to propping up the pack when the lights turn green on Sunday.