Former Formula 1 driver Anthony Davidson has said that Fernando Alonso can only win the drivers' title if Sebastian Vettel has reliability issues.
The Red Bull driver is 10 points ahead of Alonso with two races remaining.
Davidson told Sky Sports News: "Let's not kid ourselves - Vettel is in the best car compared to Alonso definitely.
"I think the only thing that is standing in Vettel's way is reliability and mistakes from the team."
If Vettel scores 15 points more than the Spaniard in the next race in Austin he will be crowned world champion for the third consecutive year.