Hamilton in driving seat for fourth world title

Lewis Hamilton will seek a fifth win in six visits to Texas this weekend and hope for further Ferrari misfortune as he bids to clinch his fourth world title at the United States Grand Prix.
The Briton leads nearest rival Sebastian Vettel by 59 points with four races remaining and will take this year's crown if he can outscore him by 16 points.
In short, that means that if Hamilton wins, Vettel must finish in the top five to keep his own challenge alive - a seemingly straightforward prospect if he and Ferrari can avoid the mishaps that have afflicted them in the last four races.

Since their home Italian Grand Prix at Monza, Ferrari have succumbed to a series of mechanical setbacks and mistakes that culminated, at the Japanese Grand Prix on October 8, in Vettel being forced to retire due to the failure of a $60 spark plug.
That embarrassing exit followed a crash with his Ferrari team-mate Kimi Raikkonen in Singapore and an engine problem in Malaysia - incidents that allowed Hamilton to capitalise for Mercedes by grabbing three wins in four races.

Hamilton now has 306 points and Vettel, the only other man to have won at Austin's Circuit of the Americas, has 247.

A dramatic, tense and hotly-contested race is in prospect on Sunday when the ceremonial preliminaries may see Hamilton 'take a knee' during the playing of the anthem in support of the protest, initiated by National Football League (NFL) players, against racial injustice and police brutality.
Mercedes boss Toto Wolff made clear that he would not stop him.
"The more you try to limit him - put him in a box - the more detrimental it will be for his performance," he said.
With temperatures forecast to continue at around 30 degrees Celsius it may be that conditions favour Ferrari's faster, but less reliable car at a track that Hamilton, chasing a sixth overall United States GP win, relishes.

Hunting his ninth win this year, Hamilton will know that Vettel is sure to mount a ferocious attack of his own to prevent him joining the German and Alain Prost as four-time champions.
Only Michael Schumacher, with seven titles, and Juan- Manuel Fangio, with five, have more and a fourth Hamilton triumph would make him the most successful British driver.
- 'Take nothing for granted' -
But as Ferrari seek to preserve their challenge with improved reliability, Hamilton's main threat may come from Red Bull's Max Verstappen, who won in Malaysia three weeks ago, or Daniel Ricciardo, like Hamilton a man very at home in America.

Fully aware that both Ferrari and Red Bull have shown superior speed in recent weeks, Wolff has, however, warned Hamilton and his team to avoid any complacency.
"The team is operating at an incredibly high level in every area and continuing to develop," he said. "But Lewis has driven brilliantly this year and, since the summer break in particular, he has been on another level.
"It has been impressive to watch him extracting everything from the car and working with the team to solve problems and improve even further.
"But we can take nothing for granted... We have seen a strong points swing in our favour in both championships -- good fortune has played its part, of course - and we have put ourselves in the right position to make the most of the opportunities.

"But nobody is allowing those good results to disguise the challenges we have faced. We approach every race with a healthy dose of scepticism."
For Fernando Alonso, it will be a chance to thank the American fans for their support of him when he took part in the Indianapolis 500 - and he plans to switch helmets and use the one he wore at 'The Brickyard' in May.
The weekend will also see New Zealand's Le Mans 24-Hours winner Brendan Hartley, a former Red Bull squad junior and reserve driver, make his debut with Toro Rosso alongside returning Daniil Kvyat.

Hartley will be the ninth Kiwi to take part in an F1 race on Sunday, if he qualifies and takes a place on the grid.
He succeeds Carlos Sainz who has been released to join Renault.