Juan Pablo Montoya wins the championship if: he finishes third or higher.
Graham Rahal wins the championship if: he wins the race, and Montoya finishes no higher than fourth. If Montoya is classified last, Rahal needs to finish eighth or better. If Rahal claims second or third, he needs Montoya to be no better than ninth or 13th respectively.
Scott Dixon will win the championship if: he wins the race and Montoya finishes no higher than seventh. Mathematically, the Kiwi can win with a third place, but he would be dependent upon Montoya finishing 18th or worse.
Will Power will win the championship if: he wins the race, and his Penske team-mate Montoya is no higher than 11th. If the reigning champion finishes second, he needs Montoya to be mired down in 21st or worse.
Helio Castroneves will win the championship if: he wins the race, and Montoya is classified no higher than 18th.
Josef Newgarden will win the championship if: he wins the race, Montoya is no higher than 24th, Rahal is no higher than ninth, Dixon is no higher than sixth, Power no better than third, and Rahal no better than second.
Scoring system for Sonoma: 100-80-70-64-60-56-52-48-44-40-38-36-34-32-30-28-26-24-22-20-18-16-14-12-10 for 1st to 25th in the classification. Drivers who retire still score.
Bonus points: 1 for leading a lap, 2 for most laps led