The 2016 Verizon IndyCar season has come down to the final race, which will once again determine the champion. There are two contenders this year, teammates Simon Pagenaud and Will Power. Both drivers have had incredible stretches during the season, yet both have four wins and seven podium finishes heading into the season-finale at Sonoma.

The point differential is 43 points, with Pagenaud having a nice cushion after Power crashed out of last weekend’s race at Watkins Glen. Power was not yet cleared to drive until yesterday, when Dr Geoffrey Billows determined that he was okay to get back in the car. That came just in time for the 2014 champion, as testing at Sonoma takes place tomorrow (Thursday) in preparation for next weekend’s race.

There will be 21 IndyCar drivers testing tomorrow, in addition to three Indy Lights drivers; Zach Veach (with Newgarden), Santiago Urrutia (with Hinchcliffe), and Andre Negrao (with Aleshin). The only current driver/team not participating in the test is KV Racing’s Sebastien Bourdais.

Now that Power is clear to drive, there will be a battle for the championship. Pagenaud and Power are the only two drivers mathematically eligible to win the title next Sunday. Scott Dixon is 104 points out of the top spot, but even if everything went his way, he would tie for the championship again, this time losing the tie-breaker for number of wins.

The 43-point deficit is interesting, given that Power missed the season-opening race at St Petersburg after a practice crash. He still managed to earn Pole position, but Oriol Servia had to drive the car for him in the race. Even though he was able to return after that, we never really saw the same Will Power until the double-header at Detroit. Power was dealing with symptoms from an inner ear infection, which plagued him for the first half of the season.

Heading into the second race of the season, Power trailed Pagenaud by 42 points. From Round 2 to Round 15, Pagenaud has outscored Power by one single point.

Power returned to form in the second race at Detroit, where he captured his first win of the season. He ended up winning four of the next six races, and the two he didn’t win, he came home in second place. It was an incredible comeback, and by the time the race at Texas resumed, Power was within three points of the championship lead.

Looking at the GoPro Grand Prix of Sonoma, you would think Power has the edge. He has three wins, four podiums, five poles, and has led a total of 276 laps. Simon on the other hand has just one podium finish (3rd) and has never led a lap at Sonoma in five starts.

What does Power need to do? It is a double-points race, but Power still realistically needs to win the race in order to have a chance at his second championship. Getting the bonus points for pole and leading the most laps wouldn’t hurt either. It may be a tough task, but it’s nothing he hasn’t done before at Sonoma.

For Pagenaud though, the math is simple. A top five finish will earn him the title, no matter what Will does in the race. Still, he must avoid getting into trouble, which is what happened to teammate Juan Montoya in the race last year, when he squandered away a 47-point lead to Dixon. Montoya made contact with Power (of all people) in that race, which really cost him. They may be teammates, but either way, Roger Penske is going to win another championship next weekend. He is going to let these two battle for it.

While we know Team Penske is going to win the title, and that only two drivers are eligible, it is still going to provide plenty of headlines. We’re either going to see Power complete one of the greatest comebacks in IndyCar history, or we will see one of the biggest turnarounds this sport has seen from one year to the next. It would also be the crowning of a first-time champion, which is always satisfying.

The off-season looms with questions abound for teams and drivers everywhere, with big name free agents possibly on the move. There may also be some manufacturer shakeup within the teams. Silly Season will be in full swing in just a few short weeks, but first, there is a championship to be decided on the west coast. The GoPro Grand Prix of Sonoma is set for September 18, with coverage beginning at 6:30 PM ET on NBC Sports Network.