What does Lewis Hamilton need to do to retain the World Championship title?
Lewis Hamilton kept his slim championship hopes alive following his second victory in eight days in Mexico on Sunday.
But the 31-year-old Briton is running out of time to overhaul Nico Rosberg at the top of the standings. With just two races remaining, he is 19 points behind his Mercedes team-mate.
Here, we take a look at how Hamilton could complete what will now surely rank as one of the finest championship fightbacks in Formula One history.
What does Hamilton need to do to win the title?
Following successive victories in America and Mexico City, Hamilton has reduced the championship deficit from 33 points to 19 but with only 50 still to play for, it is Rosberg who remains the odds-on favourite to claim his first title.
Hamilton must win in Brazil on November 13 and at the final round in Abu Dhabi on November 27, and hope that Rosberg finishes third or lower on both occasions.
Should Hamilton win in Brazil and Rosberg manage only fourth or worse, then the Briton will head to the season decider knowing a victory in the desert will be enough for a fourth title.
What does Rosberg need to do win his first championship?
For Rosberg, the objective is clear: win in Brazil, and the title is his. The German has a good record at Interlagos, having won there for each of the past two years.
Rosberg, who, in contrast to Hamilton, has enjoyed few reliability issues this year, also knows that second and third in the remaining rounds will be enough to emulate his father Keke, who won the world title in 1982.
So, it is Rosberg's title to lose?
Yes, even Mercedes boss Toto Wolff admitted on Sunday night that Rosberg is in the driving seat.
"I think for Nico it's maybe beneficial now because all this talking 'you need to finish second in order to make it to the end' is finished now," said Wolff.
"He has it in his hands. If he wins the race in Brazil, he's winning the championship early. I think this is maybe a bit easier in terms of tackling the situation with a little bit less pressure."
Is there anything Hamilton can do?
With Mercedes still the class manufacturer in the field, Hamilton must be hoping for rain in Brazil - a factor which contributed to Rosberg finishing only seventh in Monaco earlier this season - or for his team-mate to run into reliability trouble.
Hamilton can also draw on his maiden season in the sport where he led Kimi Raikkonen by 17 points heading into the final two races but missed out on the championship by a single point to the Finnish driver.