McLaren's Lewis Hamilton, Fernando Alonso and Ferrari's Kimi Raikkonen will fight for the Formula One championship in the season-ending Brazilian Grand Prix this weekend.
Briton Hamilton has 107 points, Spain's double world champion Alonso 103 and Raikkonen 100.
Raikkonen has won five races, Hamilton and Alonso four each.
The following details what each driver needs to do to win the title.
HAMILTON
Hamilton will be Formula One's youngest and first rookie champion if he finishes first or second.
If he is third, fourth or fifth, he will take the title if Alonso fails to win the race.
If he finishes fifth and Alonso is second, Hamilton will be champion on a countback to fifth place (They would be tied 4-4 on wins, 5-5 on seconds, 3-3 on thirds, 1-1 on fourths with Hamilton trumping Alonso 2-1 on fifths).
If he finishes sixth, he must hope Alonso is no higher than third and Raikkonen does not win.
If he finishes seventh and Alonso is third, Hamilton is champion on a countback to second places providing Raikkonen does not win.
If he finishes eighth, Hamilton takes the title if Alonso is no higher than fourth and Raikkonen third or lower.
Hamilton can also win the title without scoring, providing Alonso finishes no higher than fifth and Raikkonen is not in the top two.
ALONSO
The Spaniard will become the first driver since Argentina's Juan Manuel Fangio in 1957 to win successive titles with different teams if he wins the race and Hamilton is third or lower.
Second place would be enough if Hamilton is sixth or lower.
Failing that, third place will give him the title if Hamilton is eighth or lower and Raikkonen does not win.
Fourth place would be enough if Hamilton does not score and Raikkonen is no higher than third.
RAIKKONEN
The Finn must finish first or second to have a chance of his first title.
He can do it by winning, with Alonso no higher than third and Hamilton finishing sixth or lower.
A second place would be enough if Alonso is fourth (Raikkonen leads 5-4 on race wins) or worse and Hamilton scores only one point.
LEVEL ON POINTS
If Raikkonen finishes second, Alonso is fourth and Hamilton eighth, all three drivers would end the season level on 108 points.
Raikkonen will win the title on race wins.
