Courtesy of BBC Sport: 

We are now very much into the business end of the F1 season, and Lewis Hamilton has his work cut out if he is going to win a fourth world drivers’ title.
With four grands prix to go, the Briton trails Mercedes team-mate Nico Rosberg by 33 points, with a maximum of 100 available in the remaining races.
Can he come from behind to pip the German or will Rosberg be celebrating his maiden drivers’ crown? BBC Sport takes a look at how the title may be decided…
F1 points breakdown


1st: 25 points 2nd: 18 points

3rd: 15 points 4th: 12 points

5th: 10 points 6th: 8 points

7th: 6 points 8th: 4 points

9th: 2 points 10th: 1 point

Where and when can the title be won?
The United States Grand Prix on 23 October will go a long way to deciding which of the dominant Mercedes drivers wins the championship.
Hamilton has prevailed in the States in the past two seasons but is very much on the back foot as the title race heads to Austin.
Even if Hamilton wins the last four races, Rosberg only needs to finish second to him on each occasion to be sure of the title.
A retirement for Hamilton between now and the end of the season would almost certainly be the end of his hopes, although the earliest Rosberg could win the title would be following the Mexican Grand Prix in two races’ time on 30 October.
Should the fight go down to the wire in Abu Dhabi on 27 November, Hamilton will be able to draw on greater experience in that scenario than Rosberg. The Briton has battled for the title in the final race on four occasions – 2007, 2008, 2010 and 2014, with Rosberg a factor only once before, two years ago.
Lewis Hamilton’s engine fails during the Malaysian Grand Prix

Hamilton’s engine has failed in China, Russia and Malaysia this season

Will engines play a part in deciding the outcome?
Quite possibly. Hamilton’s engine failure 16 laps from home in Malaysia prevented an almost certain victory that would have left him leading the championship by five points at that stage. Rosberg’s subsequent win – emphatically backed up in Japan – has turned the tide dramatically.
Hamilton has had three engine failures this season but Rosberg says he is “not worried” that he could experience a similar problem, as “it is something that I cannot influence”.
Both Hamilton and Rosberg have two new engines left going into the final four races, which should be enough to see them through to the end of the season – barring failures of the kind experienced by the Briton in Malaysia – without incurring grid penalties.
Remaining races

23 October: United States

30 October: Mexico

13 November: Brazil

27 November: Abu Dhabi

How difficult will it be for Hamilton to topple Rosberg?
A 33-point deficit will be tough to surmount but Hamilton has already wiped out a sizeable gap this season.
He trailed Rosberg by 43 points five races in, but had established a six-point lead six races later, after winning the Hungarian Grand Prix in July.
A week later he won in Germany and had a 19-point cushion. Five races further on and there has been a 52-point swing back towards Rosberg.
It is worth remembering that championships have been won from much less promising positions.
In his debut F1 campaign in 2007, Hamilton was 17 points clear of Ferrari’s Kimi Raikkonen, who was then lying in third, with two races to go.
Under the old system offering 10 points for a win, Raikkonen triumphed in China and Brazil while Hamilton faltered, and the Finn snatched an unlikely world title.