With four races left of the F1 season, Max Verstappen appears to be on the verge of a first world championship title.
He leads title rival Lewis Hamilton by 19 points with 109 to play for.
Here's the run-in:
Nov. 14: Brazilian Grand Prix
Nov. 21: Qatar Grand Prix
Dec. 5: Saudi Arabia Grand Prix
Dec. 12: Abu Dhabi Grand Prix
F1's championship points are handed out as such: first, 25 points; second,18 points; third, 15 points; fourth, 12 points; fifth, 10 points; sixth, 8 points; seventh, 6 points; eighth, 4 points; ninth, 2 points; 10th, 1 point.
There is also one point on offer at each of the remaining four races for any driver who sets the fastest lap of the race and finishes in the top ten.
This in itself could set up some real drama in the final races. At Sunday's Mexican Grand Prix, Mercedes pitted Valtteri Bottas for fresh tyres to ensure he snatched the fastest lap from Verstappen on the final lap of the race. Bottas did not score the point as he was outside the top ten, but crucially Verstappen did not either.
The championship situation has another added element compared to previous run-ins, given the format of this weekend's Brazilian Grand Prix.
Brazil is the third and final running this season of the Saturday sprint race, which sets the grid for Sunday's race.
In that event, the top three finishers are also given points. There are three for the winner (who also officially is given pole position in the record books), two for second, one for third.
Points are then given out on Sunday as normal.
That means a driver can score a maximum of 29 points at the Brazilian Grand Prix this weekend, with 26 on offer at the three races in the Middle East.
Permutations and scenarios
Verstappen certainly looks like the outright favourite to win now.
There is a simple way to look at this. If Verstappen finishes ahead of Hamilton at both of the next two races, regardless of position, he would be able to wrap up the championship at the Saudi Arabian Grand Prix. He needs to leave that race with a championship lead of 26 points or more to be crowned champion at the first race in Jeddah.
The current form book certainly appears to be in Verstappen and Red Bull's favour. Since the end of F1's summer break in August, the Dutchman has finished first or second at every race bar the Italian Grand Prix, where he and Hamilton collided and crashed out of the race.
If Verstappen were to finish the Qatar Grand Prix with a lead of 52 points or greater he would be champion, as Hamilton would be unable to overhaul that deficit over the final two races.
On the current system used as a tiebreaker in a case of a tie, Verstappen leads Hamilton by nine race wins to five, so would win in any head-to-head if the championship finished level because if Hamilton were to win the next four races he would win the championship and it would be impossible for the two to finish level on points.
The tiebreaker is significant. Let's say Hamilton wins the next three races with Verstappen in second place, scores maximum points for fastest laps and takes the three points for the sprint race in Brazil, he would only be eight points clear of Verstappen heading into the final round in Abu Dhabi. Despite entering the finale with a point deficit, Verstappen would know he could win the title with a win and bonus point for fastest lap given the countback.
A race retirement for either driver would be hugely consequential.
Were Verstappen not to finish the next race and Hamilton were to win, for example, Hamilton would go into Qatar leading the championship. A race retirement for Hamilton at either of the next two events would all but end his title bid.
Hamilton must keep the gap to 25 points or less over the next three races if he wants the championship to keep going until the Abu Dhabi Grand Prix.