With Vettel and Alonso the only 2 folks able to do the title, here’s how they stick up:
That’s 10 points between the two.
The championship leader can always clinch the title at the penultimate round, so Vettel can now. In order for Vettel to do that he must outscore Alonso by 15 points. If he does beat Alonso by 15 points that means Vettel will win countback anyways – so he just has to draw level with Alonso on points. (If Alonso is to beat Vettel on count back, he has to win)
In order for Vettel to clinch the title in Austin, one of the following must occur:
If Vettel wins:
– Alonso finishes 5th or lower
If Vettel gets P2:
– Alonso finishes 9th or lower
If Vettel gets P3:
Alonso doesn’t score
Any other outcome means the title goes down to the wire.
And the only times those combinations have occured so far this season, were Bahrain (VET 1, ALO 7) Belgium (VET 2, ALO dnf) and Japan (VET 1, ALO dnf). So we have a probability of 83% this championship will be decided at Interlagos.