Lewis Hamilton inched closer to a sixth world championship with third place at the Japanese Grand Prix -- he can wrap it up in Mexico City on Oct. 27.
Mercedes teammate Valtteri Bottas, who is now the only other driver with a mathematical chance of clinching the title, won that race to close the gap to 64 points with 104 to play for at the remaining four races.
There will be 78 left in play after the Mexico City race, meaning Hamilton's lead over Bottas at the end of that race must be equal to or greater than that to be champion -- even if the Finn wins the remaining races, he would have seven victories to Hamilton's nine, meaning the latter would win any head-to-head tiebreaker.
Effectively, he needs at least a 14-point swing over his teammate, meaning he must finish on the podium to have a chance of sealing it.
F1's points system rewards the top ten drivers in the following fashion: 25-18-15-12-10-8-6-4-2-1. As of this year, there is also an additional point on offer for anyone who finishes in the top ten and manages to secure the fastest lap of the race.
Here is what needs to happen for the title fight to go on to the U.S. Grand Prix on Nov.3.
If Hamilton wins and claims the bonus point for fastest lap, Bottas must finish third or higher.
If Hamilton wins and does not claim the bonus point for fastest lap, Bottas must finish fourth or higher.
If Hamilton finishes second, Bottas must finish seventh or higher regardless of whether Hamilton claims the bonus point for fastest lap.
If Hamilton finishes third and claims the bonus point for fastest lap, Bottas must finish eighth or higher.
If Hamilton finishes third and does not claim the bonus point for fastest lap, Bottas must finish ninth or claim the bonus point and finish tenth.
With only 12 points on offer for fourth position, Hamilton cannot win the title if he fails to score a podium, even if Bottas fails to finish the race in that scenario.
Once secured, Hamilton will move into outright second on the all-time list of world champions. He currently is joint second with Juan Manuel Fangio, who won five titles in the 1950s.
Assuming he wins the 2019 title, he will need just one more to equal Michael Schumacher's record of seven.