Lewis Hamilton v Nico Rosberg: How the 2016 title may be decided

The gloves are off: Can Hamilton fight back or will Rosberg land a knockout blow?

There is one race to go and Lewis Hamilton has his work cut out if he is to win a fourth world drivers' title.

With one grand prix to go, the Briton trails Mercedes team-mate Nico Rosberg by 12 points, with a maximum of 25 available in the last race.

Can Hamilton 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...

How can the title be won?

Hamilton has won the past three races ahead of Rosberg, but a similar result in the final race of the season would hand the German his first title.

For Hamilton to win his fourth world title - after successes in 2008, 2014 and 2015 - he needs to claim victory in Abu Dhabi on Sunday and hope Rosberg finishes outside the top three, or does not finish at all.

If Hamilton comes second, Rosberg would have to finish outside of the top six. There is still a chance for Hamilton, albeit a slight one, if he comes third as he would need Rosberg to finish ninth, 10th, out of the points, or not finish.

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A retirement for Hamilton would gift Rosberg the title before the race has finished.

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.

Will engines play a part?

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" 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 two 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.

How difficult will it be for Hamilton?

A 12-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. Six races further on and there has been a 45-point swing back towards Rosberg.

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

It is worth remembering that championships have been won from 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.

Raikkonen appeared to be out of the world title reckoning with two races to go in 2007 but turned a 17-point deficit into a single-point championship win

What happens if both drivers finish on the same amount of points?

It is an unlikely scenario, but if both men end the season on the same points a countback system is used.

Firstly, the number of wins is used. However, this will not come into play as a deciding factor as both men have won nine races, and a 10th for Rosberg gives him the title.

Secondly, the number of runner-up places is used.

Rosberg has come second in four races, Hamilton three. If Rosberg comes seventh in Abu Dhabi and Hamilton second then both men end on 373 points, both with nine wins and both with four second-place finishes.

The world champion would then be decided by who finished third more often - and the title would be Hamilton's as he leads that 'race' 4-2.

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If Rosberg does not finish or scores no points and Hamilton comes fourth, then both men end up on 367 points. Rosberg would this time have the edge on the strength of his four second-placed finishes, compared to only three from Hamilton.