IndyCar

Top 5 are mathematically in it, with 104 points still available. But there are enough points given to the last place finisher to rule out both RHR and Dixon providing Will Power at least takes part. By my maths, the ways in which each driver would win the championship would be as follows:

Dixon – Will Power does not take part in the weekend, Dixon wins the race and scores bonus points for leading a lap, leading the most laps and scoring pole, with Castroneves finishing lower than 7th. It’s possible but a very, very long shot.

RHR – Needs to win the race and Will Power to not make the start, Castroneves 6th or lower. Again, a very long shot.

Pagenaud – Needs to win the race with all bonus points. He will need Castroneves to finish 3rd or lower, and Power to finish 21st or lower.

Castroneves – Only one with realistic chance of beating Power to the title. If he wins, Power would have to finish 8th or lower, although that may change to 7th or 9th depending on whether either score bonus points.
Castroneves could finish 2nd place and would be champion if Power finished 16th or lower, but again could go a position could be slightly changed by bonus points.
If Castroneves finishes 3rd, again, he would be champion if Power manages 21st or worse.
If Helio comes 4th, his only hope is if he manages to score all bonus points and Power finishes 22nd. If he cannot score all bonus points, 4th will not be enough no matter what happens to Power. And of course, any lower than 5th would not be enough either.

Power – it’s quite simple from his point of view. In order to cover off all outcomes, he has to:

Take part in the race weekend – this will eliminate Dixon from the running.
Start the race – RHR is out.
Finish in top 20 – Pagenaud is out.
Finish in top 6 – Castroneves can’t score enough points, Power will be champion.

It could be worth pointing out that, if last year is anything to go by, Fontana is a car-killer. Only 9 of the 25 that started were running at the finish, so Power wouldn’t need to choke again to lose another championship, if his car lets him down.