https://www.bbc.com/sport/formula1/45812129
Sebastian Vettel admitted after the Japanese Grand Prix that he and Ferrari had helped Lewis Hamilton to the verge of a fifth world title by their own failings.
"We made it a bit too easy for them in the last couple of races," the German said. "Credit to them, they executed well. But we need to look after ourselves and do our bit and then we see."
Vettel was still clinging on to the hope that he could turn things around in the remaining four races.
Yet Hamilton now has a 67-point lead and can tie up the championship if he wins the US Grand Prix on 21 October and Vettel is lower than second. And with the performance advantage Mercedes have suddenly developed in the last three races, a Mercedes one-two looks eminently possible.
The errors made by Vettel and Ferrari have been a defining story of the season. But just how would the championship be poised if they - and Mercedes - had had error-free seasons?
In other words, just how "easy" have Ferrari and Vettel made it for Hamilton?...........................................................................................................................................
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..............What is the total effect on the championship?
Adding all that up brings a total net loss to Vettel of 80 points. Which means, had Ferrari had a perfect season, he could still be leading the championship by 13 points.
That might not have changed the end result of the championship. Mercedes have made a big step forward in performance in the last three races and developed a significant advantage. If that is maintained over the remaining four grands prix, it is hard to see how Vettel could defend that lead.
At the same time, Hamilton has driven arguably his best season, and has been sensational in snatching some of the wins. It could easily be argued that only his genius put him in a position to win the races in Germany, Italy, Singapore and Russia, for example.
But, taking nothing away from Hamilton, it does go to show just how much easier Ferrari and Vettel have made it for him.