What's Lewis Hamilton's switch from McLaren to Mercedes all about, then?

Formula One correspondent David Tremayne answers all the questions posed by the British driver's decision to end a 14-year association by signing a three-year deal to join the German team next season

Lewis Hamilton will wave goodbye to McLaren, and succeed Schumacher (left) at Mercedes (AP)

Q: So, did Hamilton leave McLaren because Mercedes were offering a bigger salary?

A: It was easy to believe that initially, with talk of an annual $12m offer from Mercedes compared to McLaren's rumoured $7.5m, except that the latter was increased in recent weeks to a sum said to be a lot closer to Mercedes' offer. It could be, however, that the revised offer simply came too late to make a difference. If it is about money, it's more likely to have been XIX Entertainment seeking the big score than Hamilton.

Q: Is it about the commercial rights, then?

A: Partly. Hamilton has wanted greater freedom for some time to develop his own brand, and he was severely restricted in that aspiration by the terms of his McLaren contract. Mercedes offer him much greater freedom on the commercial side, which will enable Hamilton to build something for the future.

Q: Was there anything else that might have come into play?

A: Insiders at McLaren have hinted that Ron Dennis may have pushed the paternal side of things too much, and there's a case for thinking that, after 14 years with the team, Hamilton had to 'leave home' to show he has grown up. It's not that he was regarded as part of the furniture but that he felt the need for a new environment in which to express himself.

Q: Why swap McLaren – who have won races this season – for Mercedes, who have been off the pace of late?

A: That's the key question, especially when Hamilton recently reiterated that his number one interest is winning. That makes his decision look like career suicide, given that Mercedes have won a single race to McLaren's 16 in the past three seasons since the German manufacturer bought Brawn in their world championship-winning year. And that while McLaren have challenged for the title in each of those years, Mercedes have not.

Insiders suggest that Hamilton felt he had to 'escape' McLaren, and that with little interest from either Red Bull or Ferrari – where neither Sebastian Vettel nor Fernando Alonso would welcome such a blisteringly quick team-mate – Mercedes were the only remaining option with even any credibility.

"I know we made a very, very big financial offer, bigger than I believe any Formula One driver is enjoying today," McLaren boss Martin Whitmarsh says. "I know what we did but I think it is better for others to comment on these things rather than for me speculate."

Q: What about the suggestion that Mercedes will have an advantage in 2014 when new turbo engines come into play? Will it have an impact that McLaren are just a customer?

A McLaren have been a Mercedes customer for three years now, yet they have flogged Mercedes in the victory stakes, and there is no reason why Mercedes should have an advantage with the car they build for 2014 just because they manufacture its engine.

Q: Did Bernie Ecclestone play a role in all this?

A: Most likely. He is not unhappy to see a top driver go to a fourth top team.

Q: When did McLaren finally find out?

A: Whitmarsh says they found out on Wednesday, and that they had been working towards Hamilton staying with the team, "but we knew there was always a chance he wouldn't so we had to look other options. We knew two days ago, and at that point we signed Sergio [Perez] for next year."

Q: Does Whitmarsh regret saying he had no Plan B should Hamilton leave?

A: "I don't regret saying that because we hadn't got a contract at that point. When I judged it was the right time to do so, we moved forward with an option in place."

Q: How did Ron Dennis react, losing his long-time protégé just as he lost Ayrton Senna back in 1993?

A: "Ron is a racer," Whitmarsh says. "What is important is what we are doing with the team and he knows, as we have monitored Sergio over a number of years, that he is a massively exciting talent and we have the opportunity now to mould him. We are looking forward to competing this season successfully and also to next year."

Q: Why did McLaren opt for Perez when Ferrari, to whose Drive Academy he belongs, said he was too young and inexperienced?

A: McLaren have always been adventurous with their driver choices, most notably in recent years when they gave Hamilton a race drive for 2007. Perez has done an excellent job this year and shown himself to have the fire and commitment to win.

"Sergio is young and undeveloped but it has been proven you can sculpt drivers; we like doing that and it will be a challenge for us," Whitmarsh says. Presumably he wasn't including Juan Pablo Montoya in his comment.

Q: Will Jenson Button be McLaren's No 1 driver?

A: Both drivers will have equal status and McLaren expect them both to be vying for victory in 2013.

Q: Is this the end of the F1 road for Michael Schumacher?

A: As a driver, maybe, especially after his incompetent performance in Singapore. There has been talk of a management role at Mercedes, but with former champion Niki Lauda being appointed non-executive chairman of the board yesterday there may not be room for him. Schumacher also recently admitted to friends within Sauber that he was still interested in speaking "with any team that will have me".

Q: Does anyone else lose out in all this?

A: Nico Hulkenberg and Paul di Resta are probably the biggest losers.

The Force India drivers both entertained high hopes for 2013.Hulkenberg was thought to be in the McLaren frame and on paper was perfect for them. Di Resta hoped for Schumacher's seat at Mercedes. He should also have been a top contender for the McLaren seat, but Whitmarsh shed possible light on why he missed out when he admitted of the Hamilton/Button Dream Team: "There were some partners who were uncomfortable with the Britishness of our team and its line-up."