This year's Red Bull Air Race World Championship hinges on the outcome of this weekend's final round at the tricky Indianapolis, USA, circuit.
Held inside the famous motor speedway known effectionately as "the Brickyard" this weekend's race sees any one of four pilots still challenging for the tile of World Champion.
The Czech Republic's Martin Sonka currently sits atop the table on 63 points, with Japanese pilot Yoshi Muroya in second on 59, Canada's Pete McLeod third on 56 and US hope Kirby Chambliss fourth on 52. With 15 points awarded for a win, any one of these pilots can still take the title.
Despite a late-season revival than won him two successive podium finishes in the last two races, Australian Matt Hall is out of contention, sitting fifth on 37 points. Even if he wins the round, his best possible finish is equal fourth.
However, the Brickyard track is a great leveler, and in a season that has seen 10 out of the 14 pilots score at least one podium finish, any pilot can put in a spectacular performance or make a blinder of an error to put the championship on a knife edge.
"This track is special in many ways," said Red Bull Air Race's own track analyst. "There will be a static start and although the timing starts at Gate 1, the takeoff is very important as the pilots want to hit the first gate at the optimum speed. This means they will get the engine up to full RPM and then release the brakes for a super quick takeoff.
"There are a lot of chances for mistakes. Gates 5 to 7 are particularly tricky. Gate 5 is the Vertical Turning Manoeuvre and the pilots have to fly to vertical before they turn to Gate 6. Usually the following Gate flows from the VTM, but here in Indianapolis it's a 90-degree turn. So the pilot will be upside down when he turns to the next gate – which can be extremely difficult.'
With the track being so tight, the safety lines which pilots must stay within will be very close.
"There are three safety lines, and all of them are close to the optimum racing line," the analyst said. "The pilots will have to use all their skills to fly through this track without a penalty. The track here in Indianapolis is perfect for a fantastic season finale."
Sonka's four-point advantage over Muroya is nominal only. If the Czech pilot wins, it's game over for the championship battle, but if Muroya wins, Sonka will need to finish second to secure the title by one single point. Muroya can win with second place provided Sonka doesn't make the podium.
McLeod, the only one of the four title contenders to make the Final 4 here last year, is also the only one of the four not to take a race win this year. However, three second places and a third show he has consistent speed, and can't be discounted in the championship. McLeod will be pinning his hopes on taking the elusive win, and having Sonka finish no higher than fourth and Muroya at best third.
Veteran American Kirby Chambliss faces a more complex equation. If he can score his third win of the season and have Sonka fail to make the Final 4 and Muroya be classified no higher than fourth, he'll add an unlikely third World Championship trophy to his cabinet.
However, there is a real possibility that any number of the four, or indeed all of the four, won't make the Final 4 round, in which case the existing points advantages will decide the final championship standings.
One spanner in the works could be Australian Matt Hall. Should be come into contention for a race win early in the weekend, it will have the teams running for their calculators to work out what it means for the title race. Hall topped the qualifying table for the last round in Lausitz, Germany, and has a reputation for performing well on races over land. Should Hall win in Indianapolis this weekend, it will be just reward for a hard-fought 2017 campaign, but stand to turn the World Championship on its ear.
The final round of the 2017 Red Bull Air Race World Championship is on at Indianapolis Motor Speedway this weekend, with qualifying at 0700 Sunday morning AEDST and the race starting at 0600 Monday morning AEDST.