Nico Rosberg has taken a vital win this Sunday in the Brazilian Grand Prix, and has closed to within 17 points in the World Championship of Mercedes teammate Lewis Hamilton.
Double points have given the German a greater shot at the title than was otherwise possible with single points.
Hamilton wins with first or second, regardless of what Rosberg does.
In simplest terms, the easiest way for Rosberg to overcome the gap and win the title in two weeks at Abu Dhabi is to win (50 points) and have Hamilton come third (30 points) or worse. That scenario would net Rosberg the title by three points.
Rosberg can also win the title with second and Hamilton sixth or worse, third with Hamilton seventh or worse, fourth with Hamilton ninth or worse, or fifth with Hamilton 10th or worse.
Under standard points, Rosberg could only win the title down 17 with first or second.
In either case, Hamilton holds a 10-5 win tiebreaker for the season finale.
Here are the points permutations, double points versus standard points, between the two teammates: